WorldWideScience

Sample records for dgp-inspired braneworld scenario

  1. Phantom-like behavior of a DGP-inspired Scalar-Gauss-Bonnet gravity

    Energy Technology Data Exchange (ETDEWEB)

    Nozari, Kourosh; Azizi, Tahereh [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47416-95447, Babolsar (Iran, Islamic Republic of); Setare, M.R., E-mail: knozari@umz.ac.ir, E-mail: t.azizi@umz.ac.ir, E-mail: rezakord@ipm.ir [Faculty of Science, Department of Physics, University of Kurdistan, Pasdaran Ave., Sanandaj (Iran, Islamic Republic of)

    2009-10-01

    We study the phantom-like behavior of a DGP-inspired braneworld scenario where curvature correction on the brane is taken into account. We include a possible modification of the induced gravity on the brane by incorporating higher order curvature terms of Gauss-Bonnet type. We investigate the cosmological implications of the model and we show that the normal branch of the scenario self-accelerates in this modified scenario without introducing any dark energy component. Also, a phantom-like behavior can be realized in this model without introducing any phantom field that suffers from serious difficulties such as violation of the null energy condition.

  2. Inflationary dynamics in the braneworld scenarios

    Institute of Scientific and Technical Information of China (English)

    Zhang Kai-Yuan; Wu Pu-Xun; Yu Hong-Wei

    2013-01-01

    We analyze the attractor behaviour of the inflation field in braneworld scenarios using the Hamilton-Jacobi formalism,where the Friedmann equation has the form of H2 =ρ + ε√2ρ0ρ or H2 =ρ + ερ2/2σ,with ε =+ 1.We find that in all models the linear homogeneous perturbation can decay exponentially as the scalar field rolls down its potential.However,in the case of a-ρ2 correction to the standard cosmology with ρ < σ,the existence of an attractor solution requires (σ-ρ)/φ2 > 1.Our results show that the perturbation decays more quickly in models with positive-energy correction than in the standard cosmology,which is opposite to the case of negative-energy correction.Thus,the positive-energy modification rather than the negative one can assist the inflation and widen the range of initial conditions.

  3. Emergent universe in the braneworld scenario

    Energy Technology Data Exchange (ETDEWEB)

    Heydarzade, Y.; Hadi, H. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Darabi, F. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Sheykhi, A. [College of Sciences, Shiraz University, Physics Department and Biruni Observatory, Shiraz (Iran, Islamic Republic of)

    2016-06-15

    According to Padmanabhan's proposal, the difference between the surface degrees of freedom and the bulk degrees of freedom in a region of space may result in the acceleration of Universe expansion through the relation ΔV/Δt = N{sub sur} - N{sub bulk} where N{sub bulk} and N{sub sur} are referred to the degrees of freedom related to the matter and energy content inside the bulk and surface area, respectively (Padmanabhan, arXiv:1206.4916v1, 2012). In this paper,we study the dynamical effect of the extrinsic geometrical embedding of an arbitrary four-dimensional brane in a higher-dimensional bulk space and investigate the corresponding degrees of freedom. Considering the modification of the Friedmann equations arising from a general braneworld scenario, we obtain a correction term in Padmanabhan's relation, denoting the number of degrees of freedom related to the extrinsic geometry of the brane embedded in higher-dimensional spacetime as ΔV/Δt = N{sub sur} - N{sub bulk} - N{sub extr} where N{sub extr} is for the degree of freedom related to the extrinsic geometry of the brane, while N{sub sur} and N{sub bulk} are defined as before. Finally, we study the validity of the first and second laws of thermodynamics for this general braneworld scenario in the state of thermal equilibrium and in the presence of confined matter fields to the brane with the induced geometric matter fields. (orig.)

  4. Friedmann equations in braneworld scenarios from emergence of cosmic space

    CERN Document Server

    Sheykhi, A; Hosseini, S E

    2013-01-01

    Recently, it was argued that the spacetime dynamics can be understood by calculating the difference between the degrees of freedom on the boundary and in the bulk in a region of space. In this Letter, we apply this new idea to braneworld scenarios and extract the corresponding Friedmann equations of $(n-1)$-dimensional brane embedded in the $(n+1)$-dimensional bulk with any spacial curvature. We will also extend our study to the more general Gauss-Bonnet braneworld with curvature correction terms on the brane and in the bulk, and derive the dynamical equation in a nonflat Universe.

  5. Robustness of braneworld scenarios against tensorial perturbations

    CERN Document Server

    Bazeia, D; Menezes, R; Olmo, Gonzalo J; Rubiera-Garcia, D

    2015-01-01

    Inspired by the peculiarities of the effective geometry of crystalline structures, we reconsider thick brane scenarios from a metric-affine perspective. We show that for a rather general family of theories of gravity, whose Lagrangian is an arbitrary function of the metric and the Ricci tensor, the background and scalar field equations can be written in first-order form, and tensorial perturbations have a non negative definite spectrum, which makes them stable under linear perturbations regardless of the form of the gravity Lagrangian. We find, in particular, that the tensorial zero modes are exactly the same as predicted by Einstein's theory regardless of the scalar field and gravitational Lagrangians.

  6. Modulus stabilization in a non-flat warped braneworld scenario

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Indrani [S.N. Bose National Centre for Basic Sciences, Department of Astrophysics and Cosmology, Kolkata (India); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

    2017-05-15

    The stability of the modular field in a warped brane world scenario has been a subject of interest for a long time. Goldberger and Wise (GW) proposed a mechanism to achieve this by invoking a massive scalar field in the bulk space-time neglecting the back-reaction. In this work, we examine the possibility of stabilizing the modulus without bringing about any external scalar field. We show that instead of flat 3-branes as considered in Randall-Sundrum (RS) warped braneworld model, if one considers a more generalized version of warped geometry with de Sitter 3-brane, then the brane vacuum energy automatically leads to a modulus potential with a metastable minimum. Our result further reveals that in this scenario the gauge hierarchy problem can also be resolved for an appropriate choice of the brane's cosmological constant. (orig.)

  7. Modified Chaplygin gas inspired inflationary model in braneworld scenario

    Science.gov (United States)

    Jawad, Abdul; Rani, Shamaila; Mohsaneen, Sidra

    2016-05-01

    We investigate the modified Chaplygin gas inspired inflationary regime in the brane-world framework in the presence of standard and tachyon scalar fields. We consider the intermediate inflationary scenario and construct the slow-roll parameters, e-folding numbers, spectral index, scalar and tensor power spectra, tensor to scalar ratio for both scalar field models. We develop the ns - N and r - N planes and concluded that ns˜eq96^{+0.5}_{-0.5} and r≤0.0016 for N˜eq60^{+5}_{-5} in both cases of scalar field models as well as for all values of m. These constraints are consistent with observational data such as WMAP7, WMAP9 and Planck data.

  8. Virial mass in warped DGP-inspired L(R) gravity

    CERN Document Server

    Heydari-Fard, Malihe

    2012-01-01

    A version of the virial theorem is derived in a brane-world scenario in the framework of a warped DGP model where the action on the brane is an arbitrary function of the Ricci scalar, L(R). The extra terms in the modified Einstein equations generate an equivalent mass term (geometrical mass), which give an effective contribution to the gravitational energy and offer viable explanation to account for the virial mass discrepancy in clusters of galaxies. We also obtain the radial velocity dispersion of galaxy clusters and show that it is compatible with the radial velocity dispersion profile of such clusters. Finally, we compare the result of the model with L(R) gravity theories.

  9. Dynamics of bulk viscous pressure effected inflation in braneworld scenario

    Science.gov (United States)

    Jawad, Abdul; Ilyas, Amara; Rani, Shamaila

    2016-08-01

    The main goal of the present work is to examine the possible realization of warm chaotic inflation and logamediate inflation within the framework of a modified Chaplygin gas brane-world model. In this respect, the slow-roll parameters, number of e-folds, scalar-tensor power spectra, spectral indices, tensor-scalar ratio and running of scalar spectral index is being evaluated. These parameters are being analyzed for variable as well as constant dissipation and bulk viscous coefficients. Further, the trajectories among the inflationary parameters such as ns - ϕ , ns - r , αs - ϕ and ns -αs are also developed to examine their behavior as well as physical cosmology. Some of results of inflationary parameters in all cases are: r < 0.11, ns = 0.96 ± 0.025 and αs = - 0.019 ± 0.025 . It is interesting to mention here that the results of inflationary parameters are consistent with BICEP2, WMAP (7 + 9) and Planck data.

  10. Braneworld Black Holes

    CERN Document Server

    Whisker, Richard

    2008-01-01

    In this thesis we investigate black holes in the Randall-Sundrum braneworld scenario. We begin with an overview of extra-dimensional physics, from the original proposal of Kaluza and Klein up to the modern braneworld picture of extra dimensions. A detailed description of braneworld gravity is given, with particular emphasis on its compatibility with experimental tests of gravity. We then move on to a discussion of static, spherically symmetric braneworld black hole solutions. Assuming an equation of state for the ``Weyl term'', which encodes the effects of the extra dimension, we are able to classify the general behaviour of these solutions. We then use the strong field limit approach to investigate the gravitational lensing properties of some candidate braneworld black hole solutions. It is found that braneworld black holes could have significantly different observational signatures to the Schwarzschild black hole of standard general relativity. Rotating braneworld black hole solutions are also discussed, an...

  11. Neutrino Dark Energy and Moduli Stabilization in a BPS Braneworld Scenario

    CERN Document Server

    Zanzi, A

    2006-01-01

    A braneworld model for neutrino Dark Energy (DE) is presented. We consider a five dimensional two-branes set up with a bulk scalar field motivated by supergravity. Its low-energy effective theory is derived with a moduli space approximation (MSA). The position of the two branes are parametrized by two scalar degrees of freedom (moduli). After detuning the brane tensions a classical potential for the moduli is generated. This potential is unstable for dS branes and we suggest to consider as a stabilizing contribution the Casimir energy of bulk fields. In particular we add a massive spinor (neutrino) field in the bulk and then evaluate the Casimir contribution of the bulk neutrino with the help of zeta function regularization techniques. We construct an explicit form of the 4D neutrino mass as function of the two moduli. To recover the correct DE scale for the moduli potential the usual cosmological constant fine-tuning is necessary, but, once accepted, this model suggests a stronger connection between DE and n...

  12. Effects of Density Gradients on Braneworld Stars

    Science.gov (United States)

    Ovalle, Jorge

    During the last few years the braneworld consequences on general relativity have been studied with great interest. The implications in both, cosmological and astrophysics scenarios, have been considered for many authors. However there are some aspects of braneworld consequences which have not been clearly elucidated yet. For instance, the role played for density gradients in the astrophysics scenario is not clear so far, leaving thus the study of braneworld stars as one of the most difficult scenarios. Here it is shown an approach which allows the study of density gradients and their consequences through the Weyl fluid produced inside a stellar distributions. Some general aspects are discussed in detail.

  13. Configurational entropy in brane-world models

    Energy Technology Data Exchange (ETDEWEB)

    Correa, R. A. C., E-mail: fis04132@gmail.com [CCNH, Universidade Federal do ABC, 09210-580, Santo André, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [CMCC, Universidade Federal do ABC, 09210-580, Santo André, SP (Brazil); International School for Advanced Studies (SISSA), Via Bonomea 265, 34136, Trieste (Italy)

    2015-11-02

    In this work we investigate the entropic information on thick brane-world scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model and hence the brane-world entropic information measure is shown to be an accurate way for providing the most suitable range for the bulk AdS curvature, in particular from the informational content of physical solutions. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the configuration of the system, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy.

  14. Configurational entropy in brane-world models

    Energy Technology Data Exchange (ETDEWEB)

    Correa, R.A.C. [CCNH, Universidade Federal do ABC, Santo Andre, SP (Brazil); Rocha, Roldao da [CMCC, Universidade Federal do ABC, Santo Andre, SP (Brazil); International School for Advanced Studies (SISSA), Trieste (Italy)

    2015-11-15

    In this work we investigate the entropic information on thick brane-world scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model and hence the brane-world entropic information measure is shown to be an accurate way for providing the most suitable range for the bulk AdS curvature, in particular from the informational content of physical solutions. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the configuration of the system, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy. (orig.)

  15. Configurational entropy in brane-world models

    Science.gov (United States)

    Correa, R. A. C.; da Rocha, Roldão

    2015-11-01

    In this work we investigate the entropic information on thick brane-world scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model and hence the brane-world entropic information measure is shown to be an accurate way for providing the most suitable range for the bulk AdS curvature, in particular from the informational content of physical solutions. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the configuration of the system, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy.

  16. Braneworld cosmology and noncommutative inflation

    CERN Document Server

    Calcagni, G

    2005-01-01

    In this work we develop the patch formalism, an approach providing a very simple and compact description of braneworld-motivated cosmologies with nonstandard effective Friedmann equations. In particular, the Hubble parameter is assumed to depend on some power of the brane energy density, H^2 \\propto \\rho^q. The high-energy limit of Randall-Sundrum (q=2) and Gauss-Bonnet (q=2/3) braneworlds are considered, during an accelerating era triggered by a single ordinary or tachyonic scalar field. The inflationary dynamics, solutions, and spectra are provided. Using the latest results from WMAP and other experiments for estimates of cosmological observables, it is shown that future data and missions can in principle discriminate between standard four-dimensional and braneworld scenarios. The issue of non-Gaussianity is also studied within nonlinear perturbation theory. The introduction of a fundamental energy scale reinforces these results. Several classes of noncommutative inflationary models are considered and their...

  17. Braneworld gravastars admitting conformal motion

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Ayan; Rahaman, Farook; Islam, Sayeedul [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Govender, Megan [Durban University of Technology, Department of Mathematics, Faculty of Applied Sciences, Durban (South Africa)

    2016-01-15

    In this paper, we propose the braneworld gravastar configuration which is an alternative to the braneworld black hole. We study the Mazur and Mottola gravastar model within the context of the Randall-Sundrum type II braneworld scenario, based on the fact that our four dimensional spacetime is a three-brane, embedded in a five dimensional bulk. We present exact solutions of the modified field equations in each of the three regions making up the gravastar, namely, (I) the core, (II) the shell, and (III) the vacuum exterior. The junction conditions at each interface are fulfilled and we further explore interesting physical properties such as length, energy and entropy of the spherical distribution. (orig.)

  18. Aspects of braneworld cosmology

    Science.gov (United States)

    Vinet, Jeremie

    What is essential is invisible to the eye. Antoine de Saint-Exupery Of course, Saint-Exupery didn't have extra dimensions in mind when he wrote this famous line. Nevertheless, the recent realisation that standard model degrees of freedom can naturally be restricted to a submanifold embedded in a higher dimensional Universe means that an ingredient essential to our description of nature might quite literally be "invisible to the eye". Exploring the consequences of such braneworld scenarios has occupied a large part of the theoretical physics community over the last seven years, and this thesis is a collection of contributions to this endeavour. After reviewing the motivations for and early successes of braneworld scenarios, we examine rho2 corrections to the Hubble rate in the stabilized Randall-Sundrum I model, where the hierarchy problem is solved in a natural way, in order to ascertain whether such corrections might be of help in addressing some issues with inflation and baryogenesis. The three following chapters are concerned with six-dimensional models that have been advertised as possibly leading to a self-tuning solution to the cosmological constant problem. We examine this claim thoroughly, through the study of thick codimension-two braneworlds. This allows us to provide a generalization of the relationship between the deficit angle and the brane matter content. We also present the first derivation of the Friedmann equations on a codimension-two brane containing matter with an arbitrary equation of state, first in the context of Einstein-Hilbert gravity and then in six dimensional supergravity.

  19. Cosmological perturbations in a noncommutative braneworld inflation

    Institute of Scientific and Technical Information of China (English)

    Kourosh Nozari; Siamak Akhshabi

    2012-01-01

    We use the smeared,coherent state picture of noncommutativity to study evolution of perturbations in a noncommutative braneworld scenario.Within the standard procedure of studying braneworld cosmological perturbations,we study the evolution of the Bardeen metric potential and curvature perturbations in this model.We show that in this setup,the early stage of the universe's evolution has a transient phantom evolution with imaginary effective sound speed.

  20. Braneworld cosmology and noncommutative inflation

    Science.gov (United States)

    Calcagni, Gianluca

    2005-03-01

    In this work we develop the patch formalism, an approach providing a very simple and compact description of braneworld-motivated cosmologies with nonstandard effective Friedmann equations. In particular, the Hubble parameter is assumed to depend on some power of the brane energy density, H^2 propto rho^q. The high-energy limit of Randall-Sundrum (q=2) and Gauss-Bonnet (q=2/3) braneworlds are considered, during an accelerating era triggered by a single ordinary or tachyonic scalar field. The inflationary dynamics, solutions, and spectra are provided. Using the latest results from WMAP and other experiments for estimates of cosmological observables, it is shown that future data and missions can in principle discriminate between standard four-dimensional and braneworld scenarios. The issue of non-Gaussianity is also studied within nonlinear perturbation theory. The introduction of a fundamental energy scale reinforces these results. Several classes of noncommutative inflationary models are considered and their features analyzed in a number of ways and energy regimes. Finally, we establish dual relations between inflationary, cyclic/ekpyrotic and phantom cosmologies, as well as between scalar-driven and tachyon-driven cosmologies. The exact dualities relating the four-dimensional spectra are broken in favour of their braneworld counterparts. The dual solutions display new interesting features because of the modification of the effective Friedmann equation on the brane.

  1. Braneworld black holes

    CERN Document Server

    Gregory, Ruth

    2008-01-01

    In these lectures, I give an introduction to and overview of braneworlds and black holes in the context of warped compactifications. I first describe the general paradigm of braneworlds, and introduce the Randall-Sundrum model. I discuss braneworld gravity, both using perturbation theory, and also non perturbative results. I then discuss black holes on the brane, the obstructions to finding exact solutions, and ways of tackling these difficulties. I describe some known solutions, and conclude with some open questions and controversies.

  2. The Schwarzschild's Braneworld Solution

    CERN Document Server

    Ovalle, J

    2010-01-01

    In the context of the Randall-Sundrum braneworld, the minimal geometric deformation approach, which has been successfully used to generate exact interior solutions to Einstein's field equations for static braneworld stars with local and non-local bulk terms, is used to obtain the braneworld version of the Schwarzschild's interior solution. Using this new solution, the behaviour of the Weyl functions is elucidated in terms of the compactness for different stellar distributions.

  3. The Schwarzschild's Braneworld Solution

    Science.gov (United States)

    Ovalle, J.

    In the context of the Randall-Sundrum braneworld, the minimal geometric deformation approach, which has been successfully used to generate exact interior solutions to Einstein's field equations for static braneworld stars with local and nonlocal bulk terms, is used to obtain the braneworld version of the Schwarzschild's interior solution. Using this new solution, the behavior of the Weyl functions is elucidated in terms of the compactness for different stellar distributions.

  4. Static domain wall in braneworld gravity

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, M.C.B.; Carlesso, P.F. [UNESP, Universidade Estadual Paulista, Instituto de Fisica Teiorica, Rua Dr. Bento Teobaldo Ferraz 271, Bloco II, Barra-Funda, Caixa Postal 70532-2, Sao Paulo, SP (Brazil); Hoff da Silva, J.M. [UNESP, Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil)

    2014-01-15

    In this paper we consider a static domain wall inside a 3-brane. Different from the standard achievement obtained in General Relativity, the analysis performed here gives a consistency condition for the existence of static domain walls in a braneworld gravitational scenario. Also the behavior of the domain wall's gravitational field in the newtonian limit is shown. (orig.)

  5. Asymmetric dark matter in braneworld cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Michael T.; Whittingham, Ian B., E-mail: Michael.Meehan@my.jcu.edu.au, E-mail: Ian.Whittingham@jcu.edu.au [School of Engineering and Physical Sciences, James Cook University, Townsville, 4811 Australia (Australia)

    2014-06-01

    We investigate the effect of a braneworld expansion era on the relic density of asymmetric dark matter. We find that the enhanced expansion rate in the early universe predicted by the Randall-Sundrum II (RSII) model leads to earlier particle freeze-out and an enhanced relic density. This effect has been observed previously by Okada and Seto (2004) for symmetric dark matter models and here we extend their results to the case of asymmetric dark matter. We also discuss the enhanced asymmetric annihilation rate in the braneworld scenario and its implications for indirect detection experiments.

  6. Strong Planck constraints on braneworld and non-commutative inflation

    Energy Technology Data Exchange (ETDEWEB)

    Calcagni, Gianluca [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Kuroyanagi, Sachiko; Ohashi, Junko; Tsujikawa, Shinji, E-mail: calcagni@iem.cfmac.csic.es, E-mail: skuro@rs.tus.ac.jp, E-mail: j1211703@ed.tus.ac.jp, E-mail: shinji@rs.kagu.tus.ac.jp [Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

    2014-03-01

    We place observational likelihood constraints on braneworld and non-commutative inflation for a number of inflaton potentials, using Planck, WMAP polarization and BAO data. Both braneworld and non-commutative scenarios of the kind considered here are limited by the most recent data even more severely than standard general-relativity models. At more than 95 % confidence level, the monomial potential V(φ)∝φ{sup p} is ruled out for p ≥ 2 in the Randall-Sundrum (RS) braneworld cosmology and, for p > 0, also in the high-curvature limit of the Gauss-Bonnet (GB) braneworld and in the infrared limit of non-commutative inflation, due to a large scalar spectral index. Some parameter values for natural inflation, small-varying inflaton models and Starobinsky inflation are allowed in all scenarios, although some tuning is required for natural inflation in a non-commutative spacetime.

  7. Braneworld gravity Influence of the moduli fields

    CERN Document Server

    Barcelo, C; Barcelo, Carlos; Visser, Matt

    2000-01-01

    We consider the case of a generic braneworld geometry in the presence of one or more moduli fields (e.g., the dilaton) that vary throughout the bulk spacetime. Working in an arbitrary conformal frame, using the generalized junction conditions of gr-qc/0008008 and the Gauss--Codazzi equations, we derive the effective ``induced'' on-brane gravitational equations. As usual in braneworld scenarios, these equations do not form a closed system in that the bulk can exchange both information and stress-energy with the braneworld. We work with an arbitrary number of moduli fields described by an arbitrary sigma model, with arbitrary curvature couplings, arbitrary self interactions, and arbitrary dimension for the bulk. (The braneworld is always codimension one.) Among the novelties we encounter are modifications of the on-brane stress-energy conservation law, anomalous couplings between on-brane gravity and the trace of the on-brane stress-energy tensor, and additional possibilities for modifying the on-brane effectiv...

  8. Braneworld gravity: influence of the moduli fields

    Science.gov (United States)

    Barceló, Carlos; Visser, Matt

    2000-10-01

    We consider the case of a generic braneworld geometry in the presence of one or more moduli fields (e.g. the dilaton) that vary throughout the bulk spacetime. Working in an arbitrary conformal frame, using the generalized junction conditions of gr-qc/0008008 and the Gauss-Codazzi equations, we derive the effective ``induced'' on-brane gravitational equations. As usual in braneworld scenarios, these equations do not form a closed system in that the bulk can exchange both information and stress-energy with the braneworld. We work with an arbitrary number of moduli fields described by an arbitrary sigma model, with arbitrary curvature couplings, arbitrary self interactions, and arbitrary dimension for the bulk. (The braneworld is always codimension one.) Among the novelties we encounter are modifications of the on-brane stress-energy conservation law, anomalous couplings between on-brane gravity and the trace of the on-brane stress-energy tensor, and additional possibilities for modifying the on-brane effective cosmological constant. After obtaining the general stress-energy ``conservation'' law and the ``induced Einstein equations'' we particularize the discussion to two particularly attractive cases: for a (n-2)-brane in ([n-1] + 1) dimensions we discuss both the effect of (1) generic variable moduli fields in the Einstein frame, and (2) the effect of a varying dilaton in the string frame.

  9. Observing braneworld black holes

    CERN Document Server

    Gregory, R; Beckwith, K; Done, C; Gregory, Ruth; Whisker, Richard; Beckwith, Kris; Done, Chris

    2004-01-01

    Spacetime in the vicinity of an event horizon can be probed using observations which explore the dynamics of the accretion disc. Many high energy theories of gravity lead to modifications of the near horizon regime, potentially providing a testing ground for these theories. In this paper, we explore the impact of braneworld gravity on this region by formulating a method of deriving the general behaviour of the as yet unknown braneworld black hole solution. We use simple bounds to constrain the solution close to the horizon.

  10. Brane-world cosmology and inflation

    Indian Academy of Sciences (India)

    Misao Sasaki

    2004-10-01

    There has been substantial progress in brane-world cosmology in recent years. Much attention has been particularly paid to the second Randall–Sundrum (RS2) scenario in which a single positive-tension brane is embedded in a five-dimensional space-time, called the bulk, with a negative cosmological constant. This brane-world scenario is quite attractive because of the non-trivial geometry in the bulk and because it successfully gives four-dimensional general relativity in the low energy limit. After reviewing basic features of the RS2 scenario, we consider a brane-world inflation model driven by the dynamics of a scalar field living in the five-dimensional bulk, the so-called bulk inflaton model. An intriguing feature of this model is that the projection of the bulk inflaton on the brane behaves just like an ordinary inflaton in four dimensions in the low energy regime, 2 ℓ2 ≪ 1, where is the Hubble expansion rate of the brane and ℓ is the curvature radius of the bulk. We then discuss the cosmological perturbation on superhorizon scales in this model. We find that, even under the presence of spatial inhomogeneities, the model is indistinguishable from the standard four-dimensional inflation to (2 ℓ2). That is, the difference may appear only at O(4 ℓ4).

  11. New Constraints on Brane-World Inflation from the CMB Power Spectrum

    CERN Document Server

    Gangopadhyay, Mayukh R

    2016-01-01

    We analyze the Randal Sundrum brane-world inflation scenario in the context of the latest CMB constraints from Planck. We summarize constraints on the most popular classes of models and explore some more realistic inflaton effective potentials. The constraint on standard inflationary parameters changes in the brane-world scenario. We find that in general the brane-world scenario increases the scalar-to-tensor ratio, thus making this paradigm less consistent with the Planck constraints. However, in the cases of axion monodromy and natural inflation, the additional shift of the spectral index to smaller values actually improves the concordance of these models with the Planck constraints.

  12. Brane-world cosmology with black strings

    Science.gov (United States)

    Gergely, László Á.

    2006-07-01

    We consider the simplest scenario when black strings/cigars penetrate the cosmological brane. As a result, the brane has a Swiss-cheese structure, with Schwarzschild black holes immersed in a Friedmann-Lemaître-Robertson-Walker brane. There is no dark radiation in the model, the cosmological regions of the brane are characterized by a cosmological constant Λ and flat spatial sections. Regardless of the value of Λ, these brane-world universes forever expand and forever decelerate. The totality of source terms in the modified Einstein equation sum up to a dust, establishing a formal equivalence with the general relativistic Einstein-Straus model. However in this brane-world scenario with black strings the evolution of the cosmological fluid strongly depends on Λ. For Λ≤0 it has positive energy density ρ and negative pressure p and at late times it behaves as in the Einstein-Straus model. For (not too high) positive values of Λ the cosmological evolution begins with positive ρ and negative p, but this is followed by an epoch with both ρ and p positive. Eventually, ρ becomes negative, while p stays positive. A similar evolution is present for high positive values of Λ, however in this case the evolution ends in a pressure singularity, accompanied by a regular behavior of the cosmic acceleration. This is a novel type of singularity appearing in brane-worlds.

  13. Braneworld setup and embedding in teleparallel gravity

    Directory of Open Access Journals (Sweden)

    A. Behboodi

    2015-01-01

    Full Text Available We construct the setup of a five-dimensional braneworld scenario in teleparallel gravity. Both cases of Minkowski and Friedmann–Robertson–Walker branes embedded in anti-de Sitter bulk are studied and the effective 4D action were studied. 4-dimensional local Lorentz invariance is found to be recovered in both cases. However, due to different junction conditions, the equations governing the 4D cosmological evolution differ from general relativistic case. Using the results of Ref. [13], we consider a simple inflationary scenario in this setup. The inflation parameters are found to be modified compared to general relativistic case.

  14. Solution for a local straight cosmic string in the braneworld gravity

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, M.C.B.; Carlesso, P.F. [UNESP, Universidade Estadual Paulista, Instituto de Fisica Teorica, Rua Dr. Bento Teobaldo Ferraz 271, Bloco II, Barra-Funda, Caixa Postal 70532-2, Sao Paulo, SP (Brazil); Hoff da Silva, J.M. [UNESP, Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil)

    2015-09-15

    In this work we deal with the spacetime shaped by a straight cosmic string, emerging from local gauge theories, in the braneworld gravity context. We search for physical consequences of string features due to the modified gravitational scenario encoded in the projected gravitational equations. It is shown that cosmic strings in braneworld gravity may present significant differences when compared to the general relativity predictions, since its linear density is modified and the deficit angle produced by the cosmic string is attenuated. Furthermore, the existence of cosmic strings in that scenario requires a strong restriction to the braneworld tension: λ ≥ 3 x 10{sup -17}, in Planck units. (orig.)

  15. Configurational Entropy in Brane-world Models: A New Approach to Stability

    CERN Document Server

    Correa, R A C

    2015-01-01

    In this work we investigate the entropic information on thick brane-worlds scenarios and its consequences. The brane-world entropic information is studied for the sine-Gordon model is and hence the brane-world entropic information measure is shown an accurate way for providing the most suitable values for the bulk AdS curvature. Besides, the brane-world configurational entropy is employed to demonstrate a high organisational degree in the structure of the system configuration, for large values of a parameter of the sine-Gordon model but the one related to the AdS curvature. The Gleiser and Stamatopoulos procedure is finally applied in order to achieve a precise correlation between the energy of the system and the brane-world configurational entropy.

  16. Exact Inflation Braneworlds

    CERN Document Server

    Solomons, D M; Ellis, G; Solomons, Deon; Dunsby, Peter; Ellis, George

    2001-01-01

    In Randall-Sundrum type braneworld cosmologies, the dynamical equations on the three-brane differ from the general relativity equations by terms that carry the effects of embedding and of the free gravitational field in the five-dimensional bulk. In a FRW ansatze for the metric, we present two methods for deriving inflationary solutions to the covariant non-linear dynamical equations for the gravitational and matter fields on the brane. In the first approach we examine the constraints on the dynamical relationship between the cosmological scale factor and the scalar field driving self-interaction potential, imposed by the weak energy condition. We then investigate inflationary solutions obtained from a scalar field superpotential. Both these techniques for solving the braneworld field equations are illustrated by flat curvature models.

  17. Braneworld cosmology in $f(R,T)$ gravity

    CERN Document Server

    Moraes, P H R S

    2015-01-01

    Braneworld scenarios consider our observable universe as a brane embedded in a 5D space, named bulk. In this work, I derive the field equations of a braneworld model in a generalized theory of gravitation, namely $f(R,T)$ gravity, with $R$ and $T$, representing the Ricci scalar and the trace of the energy-momentum tensor, respectively. The cosmological parameters obtained from this approach are in agreement with recent constraints from Supernovae Ia data combined with baryon acoustic oscillations and cosmic microwave background observations, favouring such an alternative description of the universe dynamics.

  18. Revamped braneworld gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Ruoyu; /Chicago U., EFI /Chicago U.; Carena, Marcela; /Fermilab; Lykken, Joseph; /Chicago U., EFI /Chicago U. /Fermilab; Park, Minjoon; /Chicago U., EFI /Chicago U.; Santiago, Jose; /Fermilab

    2005-11-01

    Gravity in five-dimensional braneworld backgrounds often exhibits problematic features, including kinetic ghosts, strong coupling, and the vDVZ discontinuity. These problems are an obstacle to producing and analyzing braneworld models with interesting and potentially observable modifications of 4d gravity. We examine these problems in a general AdS{sub 5}/AdS{sub 4} setup with two branes and localized curvature from arbitrary brane kinetic terms. We use the interval approach and an explicit ''straight'' gauge-fixing. We compute the complete quadratic gauge-fixed effective 4d action, as well as the leading cubic order corrections. We compute the exact Green's function for gravity as seen on the brane. In the full parameter space, we exhibit the regions which avoid kinetic ghosts and tachyons. We give a general formula for the strong coupling scale, i.e. the energy scale at which the linearized treatment of gravity breaks down, for relevant regions of the parameter space. We show how the vDVZ discontinuity can be naturally but nontrivially avoided by ultralight graviton modes. We present a direct comparison of warping versus localized curvature in terms of their effects on graviton mode couplings. We exhibit the first example of DGP-like crossover behavior in a general warped setup.

  19. Stability of a tachyon braneworld

    CERN Document Server

    German, Gabriel; Kuerten, Andre M; Malagon-Morejon, Dagoberto; da Rocha, Roldao

    2016-01-01

    Within the braneworld paradigm the tachyonic scalar field has been used to generate models that attempt to solve some of the open problems that physics faces nowadays, both in cosmology and high energy physics as well. When these field configurations are produced by the interplay of higher dimensional gravity with some matter content, braneworld models must prove to be stable under small fluctuations of the background matter fields, among other consistency tests. Here we present a complete proof of the stability under scalar perturbations of tachyonic thick braneworlds with an embedded maximally symmetric 4D space-time, revealing its physical consistency. This family contains a recently reported tachyonic de Sitter thick braneworld which possesses a series of appealing properties. These features encompasses complete regularity, asymptotic flatness (instead of being asymptotically dS/AdS even when it contains a negative bulk cosmological constant and the relevant 3-brane has dS symmetry), and a graviton spectr...

  20. Simple inflationary models in Gauss-Bonnet brane-world cosmology

    Science.gov (United States)

    Okada, Nobuchika; Okada, Satomi

    2016-06-01

    In light of the recent Planck 2015 results for the measurement of the cosmic microwave background (CMB) anisotropy, we study simple inflationary models in the context of the Gauss-Bonnet (GB) brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index (n s) and the tensor-to-scalar ratio (r) from those obtained in the standard cosmology. In particular, the predicted r values in the inflationary models favored by the Planck 2015 results are suppressed due to the GB brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall-Sundrum brane-world cosmology, where the r values are enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the GB brane-world cosmology can be tested by more precise measurements of n s and future observations of the CMB B-mode polarization.

  1. Brane-world cosmology with black strings

    CERN Document Server

    Gergely, L A

    2006-01-01

    We consider the simplest scenario when black strings (cigars) penetrate the cosmological brane. As a result, the brane has a Swiss-cheese structure, with Schwarzschild black holes immersed in a Friedmann-Lema\\^{\\i}tre-Robertson-Walker brane. There is no dark radiation in the model, the cosmological regions of the brane are characterized by a cosmological constant $\\Lambda$ and flat spatial sections. Regardless of the value of $\\Lambda$, these brane-world universes forever expand and forever decelerate. The totality of source terms in the modified Einstein equation sum up to a dust, establishing a formal equivalence with the general relativistic Einstein-Straus model. However in this brane-world scenario with black strings the evolution of the cosmological fluid strongly depends on $\\Lambda$. For $\\Lambda$ less or equal to zero it has positive energy density $\\rho$ and negative pressure $p$ and at late times it behaves as in the Einstein-Straus model. For (not too high) positive values of $\\Lambda$ the cosmolo...

  2. Stability of a tachyon braneworld

    Energy Technology Data Exchange (ETDEWEB)

    Germán, Gabriel [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apartado Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Herrera-Aguilar, Alfredo [Instituto de Física, Benemérita Universidad Autónoma de Puebla,Apartado Postal J-48, 72570, Puebla, Puebla (Mexico); Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo,Ciudad Universitaria, CP 58040, Morelia, Michoacán (Mexico); Kuerten, André Martorano [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apartado Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC),Avenida dos Estados, 5001, Santo André, SP (Brazil); Malagón-Morejón, Dagoberto [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apartado Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Rocha, Roldão da [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC (UFABC),Avenida dos Estados, 5001, Santo André, SP (Brazil)

    2016-01-26

    Within the braneworld paradigm the tachyonic scalar field has been used to generate models that attempt to solve some of the open problems that physics faces nowadays, both in cosmology and high energy physics as well. When these field configurations are produced by the interplay of higher dimensional warped gravity with some matter content, braneworld models must prove to be stable under the whole set of small fluctuations of the gravitational and matter fields background, among other consistency tests. Here we present a complete proof of the stability under scalar perturbations of tachyonic thick braneworlds with an embedded maximally symmetric 4D space-time, revealing its physical consistency. This family of models contains a recently reported tachyonic de Sitter thick braneworld which possesses a series of appealing properties. These features encompass complete regularity, asymptotic flatness (instead of being asymptotically dS or AdS) even when it contains a negative bulk cosmological constant, a relevant 3-brane with dS metric which naturally arises from the full set of field equations of the 5D background (it is not imposed), qualitatively describing the inflationary epochs of our Universe, and a graviton spectrum with a single zero mode bound state that accounts for the 4D graviton localised on the brane and is separated from the continuum of Kaluza-Klein massive graviton excitations by a mass gap. The presence of this mass gap in the graviton spectrum makes the extra-dimensional corrections to Newton’s law decay exponentially. Gauge vector fields with a single massless bound state in its mass spectrum are also localised on this braneworld model a fact that allows us to recover the Coulomb’s law of our 4D world. All these properties of the above referred tachyonic braneworld together with the positive stability analysis provided in this work, constitute a firm step towards the construction of realistic cosmological models within the braneworld paradigm.

  3. Stability of a tachyon braneworld

    Science.gov (United States)

    Germán, Gabriel; Herrera-Aguilar, Alfredo; Martorano Kuerten, André; Malagón-Morejón, Dagoberto; da Rocha, Roldão

    2016-01-01

    Within the braneworld paradigm the tachyonic scalar field has been used to generate models that attempt to solve some of the open problems that physics faces nowadays, both in cosmology and high energy physics as well. When these field configurations are produced by the interplay of higher dimensional warped gravity with some matter content, braneworld models must prove to be stable under the whole set of small fluctuations of the gravitational and matter fields background, among other consistency tests. Here we present a complete proof of the stability under scalar perturbations of tachyonic thick braneworlds with an embedded maximally symmetric 4D space-time, revealing its physical consistency. This family of models contains a recently reported tachyonic de Sitter thick braneworld which possesses a series of appealing properties. These features encompass complete regularity, asymptotic flatness (instead of being asymptotically dS or AdS) even when it contains a negative bulk cosmological constant, a relevant 3-brane with dS metric which naturally arises from the full set of field equations of the 5D background (it is not imposed), qualitatively describing the inflationary epochs of our Universe, and a graviton spectrum with a single zero mode bound state that accounts for the 4D graviton localised on the brane and is separated from the continuum of Kaluza-Klein massive graviton excitations by a mass gap. The presence of this mass gap in the graviton spectrum makes the extra-dimensional corrections to Newton's law decay exponentially. Gauge vector fields with a single massless bound state in its mass spectrum are also localised on this braneworld model a fact that allows us to recover the Coulomb's law of our 4D world. All these properties of the above referred tachyonic braneworld together with the positive stability analysis provided in this work, constitute a firm step towards the construction of realistic cosmological models within the braneworld paradigm.

  4. Brane-World Multigravity

    CERN Document Server

    Papazoglou, A

    2001-01-01

    In this thesis, we discuss the idea of multigravity, namely the possibility that a significant component of gravity that we feel at intermediate distances (1 mm < r < 10^26 cm) is due to massive but ultralight gravitons. We demonstrate how this phenomenon can be realized in brane-world models in a spacetime with more than four dimensions and discuss how modifications of gravity at cosmological scales emerge as a consequence. Firstly, we consider five dimensional multigravity models with flat branes. We see how the existence of freely moving negative tension branes gives rise to ultralight graviton Kaluza-Klein states. Secondly, we study the moduli corresponding to the position of the branes and the size of the extra dimension, the radions and the dilaton respectively. We show that the radions corresponding to negative tension branes have wrong sign kinetic term. We also derive a stabilization condition for the dilaton in a brane model with general bulk scalar field dynamics. Thirdly, we show how we can ...

  5. Gravity localization in sine-Gordon braneworlds

    CERN Document Server

    Cruz, W T; Sousa, L J S; Almeida, C A S

    2016-01-01

    In this work we study two types of five-dimensional braneworld models given by sine-Gordon potentials. In both scenarios, the thick brane is generated by a real scalar field coupled to gravity. We focus our investigation on the localization of graviton field and the behaviour of the massive spectrum. In particular, we analyse the localization of massive modes by means of a relative probability method in a Quantum Mechanics context. Initially, considering a scalar field sine-Gordon potential, we find a resonance to the graviton at zero mode. However, when we consider a double sine-Gordon potential, the brane structure is changed allowing the existence of massless and massive resonant states. The new results show how the existence of an internal structure can aid in the emergence of massive resonant modes on the brane.

  6. Gravity localization in sine-Gordon braneworlds

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, W.T., E-mail: wilamicruz@gmail.com [Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Juazeiro do Norte, 63040-540 Juazeiro do Norte, Ceará (Brazil); Maluf, R.V., E-mail: r.v.maluf@fisica.ufc.br [Departamento de Física, Universidade Federal do Ceará (UFC), C.P. 6030, 60455-760 Fortaleza, Ceará (Brazil); Sousa, L.J.S., E-mail: luisjose@fisica.ufc.br [Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Canindé, 62700-000 Canindé, Ceará (Brazil); Almeida, C.A.S., E-mail: carlos@fisica.ufc.br [Departamento de Física, Universidade Federal do Ceará (UFC), C.P. 6030, 60455-760 Fortaleza, Ceará (Brazil)

    2016-01-15

    In this work we study two types of five-dimensional braneworld models given by sine-Gordon potentials. In both scenarios, the thick brane is generated by a real scalar field coupled to gravity. We focus our investigation on the localization of graviton field and the behaviour of the massive spectrum. In particular, we analyse the localization of massive modes by means of a relative probability method in a Quantum Mechanics context. Initially, considering a scalar field sine-Gordon potential, we find a localized state to the graviton at zero mode. However, when we consider a double sine-Gordon potential, the brane structure is changed allowing the existence of massive resonant states. The new results show how the existence of an internal structure can aid in the emergence of massive resonant modes on the brane.

  7. Simple inflationary models in Gauss-Bonnet brane-world cosmology

    CERN Document Server

    Okada, Nobuchika

    2014-01-01

    In light of the recent measurements of the CMB anisotropy by the WMAP and Planck satellite experiments and the observation of CMB $B$-mode polarization announced by the BICEP2 collaboration, we study simple inflationary models in the context of the Gauss-Bonnet brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology. In particular, the power spectrum of tensor perturbation is suppressed due to the Gauss-Bonnet brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall-Sundrum brane-world cosmology where the power spectrum is enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the Gauss-Bonnet ...

  8. Cosmological constraints on Agegraphic dark energy in DGP braneworld gravity

    CERN Document Server

    Farajollahi, H; Fadakar, G F

    2016-01-01

    A proposal to study the original and new agegraphic dark energy in DGP braneworld cosmology is presented in this work. To verify our model with the observational data, the model is constrained by a variety of independent measurements such as Hubble parameter, cosmic microwave background anisotropies, and baryon acoustic oscillation peaks. The best fitting procedure shows the effectiveness of agegraphic parameter $n$ in distinguishing between the original and new agegraphic dark energy scenarios and subsequent cosmological findings. In particular, the result shows that in both scenarios, our universe enters an agegraphic dark energy dominated phase.

  9. Braneworld Black Hole Gravitational Lensing

    Science.gov (United States)

    Liang, Jun

    2017-04-01

    A class of braneworld black holes, which I called as Bronnikov-Melnikov-Dehen (BMD) black holes, are studied as gravitational lenses. I obtain the deflection angle in the strong deflection limit, and further calculate the angular positions and magnifications of relativistic images as well as the time delay between different relativistic images. I also compare the results with those obtained for Schwarzschild and two braneworld black holes, i.e., the tidal Reissner-Nordström (R-N) and the Casadio-Fabbri-Mazzacurati (CFM) black holes. Supported by Natural Science Foundation of Education Department of Shannxi Provincial Government under Grant No. 15JK1077, and Doctorial Scientific Research Starting Fund of Shannxi University of Science and Technology under Grant No. BJ12-02

  10. Self-accelerating Warped Braneworlds

    Energy Technology Data Exchange (ETDEWEB)

    Carena, Marcela; Lykken, Joseph; /Fermilab; Park, Minjoon; /UC, Davis; Santiago, Jose; /Fermilab

    2006-11-01

    Braneworld models with induced gravity have the potential to replace dark energy as the explanation for the current accelerating expansion of the Universe. The original model of Dvali, Gabadadze and Porrati (DGP) demonstrated the existence of a ''self-accelerating'' branch of background solutions, but suffered from the presence of ghosts. We present a new large class of braneworld models which generalize the DGP model. Our models have negative curvature in the bulk, allow a second brane, and have general brane tensions and localized curvature terms. We exhibit three different kinds of ghosts, associated to the graviton zero mode, the radion, and the longitudinal components of massive graviton modes. The latter two species occur in the DGP model, for negative and positive brane tension respectively. In our models, we find that the two kinds of DGP ghosts are tightly correlated with each other, but are not always linked to the feature of self-acceleration. Our models are a promising laboratory for understanding the origins and physical meaning of braneworld ghosts, and perhaps for eliminating them altogether.

  11. On-brane data for braneworld stars

    CERN Document Server

    Visser, M; Visser, Matt; Wiltshire, David L.

    2003-01-01

    Stellar structure in braneworlds is rather different from that in ordinary general relativity. We completely solve the ``on brane'' 4-dimensional Gauss--Codazzi equations for an arbitrary static spherically symmetric star in a Randall-Sundrum type II braneworld. We then indicate how this on-brane boundary data can be propagated into the bulk to determine the 5-dimensional spacetime geometry.

  12. Chapter 8. Black Holes in Braneworld Models

    Science.gov (United States)

    Tanahashi, N.; Tanaka, T.

    In this review, we summarize current understandings of blackhole solutions in various braneworld models, including the Arkani-Hamed-Dimopoulos-Dvali model, the Randall-Sundrum (RS) models, Karch-Randall (KR) model and the Dvali-Gabadadze-Porrati model. After illustrating basic properties of each braneworld model, we introduce the bulk/brane correspondence in the RS and KR braneworld models, adding supporting evidence for it. We then summarize the studies on braneworld black hole solutions, which consist of constructing exact or approximate solutions and investigating the phase diagram of solutions. In the study of phase diagram, we will also expound the implications of the bulk/brane correspondence to the braneworld black holes.

  13. Casadio-Fabbri-Mazzacurati Black Strings and Braneworld-induced Quasars Luminosity Corrections

    CERN Document Server

    da Rocha, Roldao; Kuerten, A M; Coimbra-Araujo, C H

    2013-01-01

    This paper aims to evince the corrections on the black string warped horizon in the braneworld paradigm, and their drastic physical consequences, as well as to provide subsequent applications in astrophysics. Our analysis concerning black holes on the brane departs from the Schwarzschild case, where the black string is unstable to large-scale perturbation. The cognizable measurability of the black string horizon corrections due to braneworld effects is investigated, as well as their applications in the variation of quasars luminosity. We delve into the case wherein two solutions of Einstein's equations proposed by Casadio, Fabbri, and Mazzacurati, regarding black hole metrics presenting a post-Newtonian parameter measured on the brane. In this scenario, it is possible to analyze purely the braneworld corrected variation in quasars luminosity, by an appropriate choice of the post-Newtonian parameter that precludes Hawking radiation on the brane: the variation in quasars luminosity is uniquely provided by pure ...

  14. A family of braneworld wormholes

    CERN Document Server

    Delgado, Gabino Estevez; Mora-Luna, Refugio Rigel

    2016-01-01

    A wormhole solution is presented on a braneworld scenery, the material source is given by a perfect fluid on brane that does not violate the energy conditions. we propose an ansatz for the state equation resulting in a family of solutions that satisfy necessary conditions over the free parameters of the solution. The effect of projecting the 5D Weyl tensor components on the brane, give the conditions to have a wormhole satisfying the NEC, besides simultaneously guaranteeing the absence of horizons. Furthermore, our model predicts an astronomical bound for the wormhole throat.

  15. Randall-Sundrum vs. Holographic Braneworld

    CERN Document Server

    Bilic, Neven

    2016-01-01

    A mapping between two braneworld cosmologies -- Randall-Sundrum and holographic -- is explicitly constructed. The cosmologies are governed by the appropriate modified Friedman equations. A relationship between the corresponding Hubble rates is established.

  16. Asymmetric Swiss-cheese brane-worlds

    Science.gov (United States)

    Gergely, László Á.; Képíró, Ibolya

    2007-07-01

    We study a brane-world cosmological scenario with local inhomogeneities represented by black holes. The brane is asymmetrically embedded into the bulk. The black strings/cigars penetrating the Friedmann brane generate a Swiss-cheese-type structure. This universe forever expands and decelerates, as its general relativistic analogue. The evolution of the cosmological fluid, however, can proceed along four branches, two allowed to have positive energy density, and one of them having the symmetric embedding limit. On this branch a future pressure singularity can arise for either (a) a difference in the cosmological constants of the cosmological and black hole brane regions or (b) a difference in the left and right bulk cosmological constants. While behaviour (a) can be avoided by a redefinition of the fluid variables, (b) establishes a critical value of the asymmetry over which the pressure singularity occurs. We introduce the pressure singularity censorship which bounds the degree of asymmetry in the bulk cosmological constant. We also show as a model-independent generic feature that the asymmetry source term due to the bulk cosmological constant increases in the early universe. In order to obey the nucleosynthesis constraints, the brane tension should be constrained therefore both from below and from above. With the maximal degree of asymmetry obeying the pressure singularity censorship, the higher limit is ten times the lower limit. The degree of asymmetry allowed by present cosmological observations is, however, much less, pushing the upper limit to infinity.

  17. On Newton's law in supersymmetric braneworld models

    Energy Technology Data Exchange (ETDEWEB)

    Palma, G.A.

    2007-05-15

    We study the propagation of gravitons within 5-D supersymmetric braneworld models with a bulk scalar field. The setup considered here consists of a 5-D bulk spacetime bounded by two 4-D branes localized at the fixed points of an S{sup 1}/Z{sub 2} orbifold. There is a scalar field {phi} in the bulk which, provided a superpotential W({phi}), determines the warped geometry of the 5-D spacetime. This type of scenario is common in string theory, where the bulk scalar field {phi} is related to the volume of small compact extra dimensions. We show that, after the moduli are stabilized by supersymmetry breaking terms localized on the branes, the only relevant degrees of freedom in the bulk consist of a 5-D massive spectrum of gravitons. Then we analyze the gravitational interaction between massive bodies localized at the positive tension brane mediated by these bulk gravitons. It is shown that the Newtonian potential describing this interaction picks up a non-trivial contribution at short distances that depends on the shape of the superpotential W({phi}). We compute this contribution for dilatonic braneworld scenarios W({phi})=e{sup {alpha}}{sup {phi}} (where {alpha} is a constant) and discuss the particular case of 5-D Heterotic M-theory: It is argued that a specific footprint at micron scales could be observable in the near future. (orig.)

  18. Scenarios

    NARCIS (Netherlands)

    Pérez-Soba, Marta; Maas, Rob

    2015-01-01

    We cannot predict the future with certainty, but we know that it is influenced by our current actions, and that these in turn are influenced by our expectations. This is why future scenarios have existed from the dawn of civilization and have been used for developing military, political and economic

  19. Scenario

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1996-01-01

    The main purpose of this paper is to give a synthetic presentation of hte well-known scenario method. Different schools and traditions will be shortly presented. In addition guidelines for hte use of this method will be discussed. Finally, applications will also be outlined as well as some critic...

  20. Cosmological aspects of a vector field model

    CERN Document Server

    Sadatian, S Davood

    2012-01-01

    We have studied a DGP-inspired braneworld scenario where the idea of Lorentz invariance violation has been combined into a specifying preferred frame that embed a dynamical normal vector field to brane. We propose the Lorentz violating DGP brane models with enough parameters can explain crossing of phantom divide line. Also we have considered the model for proper cosmological evolution that is according to the observed behavior of the equation of state. In other view point, we have described a Rip singularity solution of model that occur in this model.

  1. Radion Dynamics in BPS Braneworlds

    CERN Document Server

    Webster, S L

    2004-01-01

    We examine the moduli dynamics of supergravity-inspired BPS braneworlds, clarifying the role of bulk scalar fields in brane collisions. The model contains the Randall-Sundrum model both with and without a free, massless bulk scalar field. Its low-energy effective theory is derived with a moduli space approximation (MSA) and agrees with the corresponding results derived elsewhere. In the Randall-Sundrum case we show the MSA to be an accurate description of the system in the small-radion regime. Whilst the presence of a bulk scalar has little qualitative effect on the radion effective potential, the corresponding modulus field diverges during a brane collision. This renders the event singular, even in the Brane Frame with an exact FRW geometry, via its contribution to the induced Friedmann equation on the brane, and also calls into doubt the self-consistency of the effective theory.

  2. Scenarios

    Directory of Open Access Journals (Sweden)

    Joao M. Goncalves

    2015-12-01

    Full Text Available Personal information is increasingly gathered and used for providing services tailored to user preferences, but the datasets used to provide such functionality can represent serious privacy threats if not appropriately protected. Work in privacy-preserving data publishing targeted privacy guarantees that protect against record re-identification, by making records indistinguishable, or sensitive attribute value disclosure, by introducing diversity or noise in the sensitive values. However, most approaches fail in the high-dimensional case, and the ones that don't introduce a utility cost incompatible with tailored recommendation scenarios. This paper aims at a sensible trade-off between privacy and the benefits of tailored recommendations, in the context of privacy-preserving data publishing. We empirically demonstrate that significant privacy improvements can be achieved at a utility cost compatible with tailored recommendation scenarios, using a simple partition-based sanitization method.

  3. Gravity localization in a string-cigar braneworld

    CERN Document Server

    Silva, Jose Euclides G; Almeida, C A S

    2012-01-01

    We proposed a six dimensional string-like braneworld built from a warped product between a 3-brane and the Hamilton cigar soliton space, the string-cigar braneworld. This transverse manifold is a well-known steady solution of the Ricci flow equation that describes the evolution of a manifold. The resulting bulk is an interior and exterior metric for a thick string. This is a physical and feasible scenario since the source satisfies the dominant energy condition. It is possible to realize the geometric flow as a result of variations of the matter content of the brane, actually, as its tensions. Furthermore, the Ricci flow defines a family of string-like branes and we studied the effects that the evolution of the transverse space has on the geometric and physical quantities. The geometric flow makes the cosmological constant and the relationship between the Planck masses evolves. The gravitational massless mode remains trapped to the brane and the width of the mode depends on the evolution parameter. For the Ka...

  4. Constraints on the braneworld from compact stars

    CERN Document Server

    Felipe, R Gonzalez; Martinez, A Perez

    2016-01-01

    According to the braneworld idea, ordinary matter is confined on a 3-dimensional space (brane) that is embedded in a higher-dimensional space-time where gravity propagates. In this work, after reviewing the limits coming from general relativity, finiteness of pressure and causality on the brane, we derive observational constraints on the braneworld parameters from the existence of stable compact stars. The analysis is carried out by solving numerically the brane-modified Tolman-Oppenheimer-Volkoff equations, using different representative equations of state to describe matter in the star interior. The cases of normal dense matter, pure quark matter and hybrid matter are considered.

  5. Five Dimensional f(R) Braneworld Models

    CERN Document Server

    da Silva, J M Hoff

    2011-01-01

    After incorporating the f(R) gravity into the general braneworld sum rules scope, it is shown that some particular class of warped five dimensional nonlinear braneworld models, which may be interesting for the hierarchy problem solution, still require a negative tension brane. For other classes of warp factors (suitable and not suitable for approaching the hierarchy problem) it is not necessary any negative brane tension in the compactification scheme. In this vein, it is argued that in the bulk f(R) gravity context, some types of warp factors may be useful for approaching the hierarchy problem and for evading the necessity of a negative brane tension in the compactification scheme.

  6. Constraints on the braneworld from compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Felipe, R.G. [Instituto Politecnico de Lisboa, ISEL, Instituto Superior de Engenharia de Lisboa, Lisboa (Portugal); Instituto Superior Tecnico, Universidade de Lisboa, Departamento de Fisica, Centro de Fisica Teorica de Particulas, CFTP, Lisboa (Portugal); Paret, D.M. [Universidad de la Habana, Departamento de Fisica General, Facultad de Fisica, La Habana (Cuba); Martinez, A.P. [Instituto de Cibernetica, Matematica y Fisica (ICIMAF), La Habana (Cuba); Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Mexico, Distrito Federal (Mexico)

    2016-06-15

    According to the braneworld idea, ordinary matter is confined on a three-dimensional space (brane) that is embedded in a higher-dimensional space-time where gravity propagates. In this work, after reviewing the limits coming from general relativity, finiteness of pressure and causality on the brane, we derive observational constraints on the braneworld parameters from the existence of stable compact stars. The analysis is carried out by solving numerically the brane-modified Tolman-Oppenheimer-Volkoff equations, using different representative equations of state to describe matter in the star interior. The cases of normal dense matter, pure quark matter and hybrid matter are considered. (orig.)

  7. Gauge fields in a string-cigar braneworld

    Energy Technology Data Exchange (ETDEWEB)

    Costa, F.W.V., E-mail: wagner@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760, Fortaleza, Ceará (Brazil); FAFIDAM, Universidade Estadual do Ceará, Limoeiro do Norte, Ceará (Brazil); Silva, J.E.G., E-mail: euclides@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760, Fortaleza, Ceará (Brazil); Veras, D.F.S., E-mail: franklin@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760, Fortaleza, Ceará (Brazil); Almeida, C.A.S., E-mail: carlos@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760, Fortaleza, Ceará (Brazil)

    2015-07-30

    In this work, we investigate the properties of the Abelian gauge vector field in the background of a string-cigar braneworld. Both the thin and thick brane limits are considered. The string-cigar scenario can be regarded as an interior and exterior string-like solution. The source undergoes a geometric Ricci flow which is related to a variation of the bulk cosmological constant. The Ricci flow changes the width and amplitude of the massless mode at the brane core and recovers the usual string-like behavior at large distances. By means of suitable numerical methods, we attain the Kaluza–Klein (KK) spectrum for the string-like and the string-cigar models. For the string-cigar model, the KK modes are smooth near the brane and their amplitude are enhanced by the brane core. Furthermore, the analogue Schrödinger potential is also regulated by the geometric flow.

  8. Black Hole Formation in Randall-Sundrum II Braneworlds.

    Science.gov (United States)

    Wang, Daoyan; Choptuik, Matthew W

    2016-07-01

    We present the first numerical study of the full dynamics of a braneworld scenario, working within the framework of the single brane model of Randall and Sundrum. In particular, we study the process of gravitational collapse driven by a massless scalar field which is confined to the brane. Imposing spherical symmetry on the brane, we show that the evolutions of sufficiently strong initial configurations of the scalar field result in black holes that have finite extension into the bulk. Furthermore, we find preliminary evidence that the black holes generated form a unique sequence, irrespective of the details of the initial data. The black hole solutions we obtain from dynamical evolutions are consistent with those previously computed from a static vacuum ansatz.

  9. The Cosmological Constant Problem from a Brane-World Perspective

    CERN Document Server

    Förste, S; Lavignac, Stephane; Nilles, Hans Peter; Forste, Stefan; Lalak, Zygmunt; Lavignac, St\\'ephane; Nilles, Hans Peter

    2000-01-01

    We point out several subtleties arising in brane-world scenarios of cosmological constant cancellation. We show that solutions with curvature singularities are inconsistent, unless the contribution to the effective four-dimentional cosmological constant of the physics that resolves the singularities is fine-tuned. This holds for both flat and curved branes. Irrespective of this problem, we then study an isolated class of flat solutions in models where a bulk scalar field with a vanishing potential couples to a 3-brane. We give an example where the introduction of a bulk scalar potential results in a nonzero cosmological constant. Finally we comment on the stability of classical solutions of the brane system with respect to quantum corrections.

  10. Dark matter relic density in Gauss-Bonnet braneworld cosmology

    CERN Document Server

    Meehan, Michael T

    2014-01-01

    The relic density of symmetric and asymmetric dark matter in the Gauss-Bonnet braneworld cosmology is investigated. The reduced expansion rate in this scenario delays particle freeze-out, leading to relic abundances which are suppressed by up to $\\mathcal{O}(10^{-3})$. In this case the annihilation cross section must be reduced by up to two orders of magnitude below the canonical value $\\langle\\sigma v\\rangle \\approx 2\\times 10^{-26}$ cm$^3$s$^{-1}$ to reconcile the predicted dark matter density with observation. We use the latest observational bound $\\Omega_{DM}h^2 = 0.1187 \\pm 0.0017$ to constrain the various model parameters and discuss the implications for direct/indirect dark matter detection experiments as well as dark matter particle models.

  11. Black hole formation in Randall-Sundrum II braneworlds

    CERN Document Server

    Wang, Daoyan

    2016-01-01

    We present the first numerical study of the full dynamics of a braneworld scenario, working within the framework of the single brane model of Randall and Sundrum (RSII). In particular, we study the process of gravitational collapse driven by a massless scalar field which is confined to the brane. Imposing spherical symmetry on the brane, we show that the evolutions of sufficiently strong initial configurations of the scalar field result in black holes that have finite extension into the bulk. Furthermore, we find preliminary evidence that the black holes generated form a unique sequence, irrespective of the details of the initial data. The black hole solutions we obtain from dynamical evolutions are consistent with those previously computed from a static vacuum ansatz.

  12. A smoothed string-like braneworld in six dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, J.C.B.; Silva, J.E.G.; Veras, D.F.S.; Almeida, C.A.S. [Universidade Federal do Ceara, Departamento de Fisica, C.P. 6030, Fortaleza, Ceara (Brazil)

    2015-03-01

    We propose a static and axisymmetric braneworld in six dimensions as a string-like model extension. For a subtle warp function, this scenario provides near brane corrections. By varying the bulk cosmological constant, we obtain a source which passes through different phases. The solution is defined both for the interior and for the exterior of the string and satisfies all the energy conditions. A smoothed gravitational massless mode is localized on the brane, of which the core is displaced from the origin. In contrast to the thin-string model, the massive solutions have a high amplitude near the brane. Furthermore, by means of an analog quantum potential analysis, we show that only s-wave gravitational Kaluza-Klein modes are permissible. (orig.)

  13. Dirac-Born-Infeld Field Trapped in the Braneworld

    CERN Document Server

    Garcia-Salcedo, Ricardo; Gonzalez, Tame; Moreno, Claudia; Quiros, Israel

    2009-01-01

    We apply the dynamical systems tools to study the (linear) cosmic dynamics of a Dirac-Born-Infeld-type field trapped in the braneworld. We focus, exclusively, in Randall-Sundrum and in Dvali-Gabadadze-Porrati brane models. We analyze the existence and stability of asymptotic solutions for the AdS throat and the quadratic potential. It is demonstrated, in particular, that in the ultra-relativistic approximation matter-scaling and scalar field-dominated solutions always arise. In the first scenario the empty universe is the past attractor, while in the second model the past attractor is the matter-dominated phase. Chaotic behaviour of the probe trajectories in the phase space -- originated by the non-linear effects of the Dirac-Born-Infeld field -- is appreciable at late times. These non-linear effects conspire against infra-red modifications of the late-time cosmic dynamics.

  14. Confluent Heun functions in gauge theories on thick braneworlds

    CERN Document Server

    Cunha, M S

    2011-01-01

    We investigate the propagation modes of gauge fields in an infinite Randall-Sundrum scenario. In this model a sine-Gordon soliton represents our thick four-dimensional braneworld while an exponentially coupled scalar acts for the dilaton field. For the gauge-field motion we find a differential equation which can be transformed into a confluent Heun equation. By means of another change of variables we obtain a related Schrodinger equation with a family of symmetric rational (\\gamma-\\omega z^2)/(1-z^2)^2 potential functions. We discuss both results and present the infinite spectrum of analytical solutions for the gauge field. Finally, we assess the existence and the relative weights of Kaluza-Klein modes in the present setup.

  15. Braneworld Inflation with Induced Gravity and Curvature Effect

    Institute of Scientific and Technical Information of China (English)

    Kourosh Nozari; S.Shafizadeh

    2011-01-01

    We construct a general braneworld inflation scenario where the inflaton field evolves on the DGP brahe and curvature effects are taken into account via incorporation of the Gauss-Bonnet term in the bulk action. While induced gravity on the DGP brahe modifies the IR limit of general relativity, the Gauss-Bonnet term in the bulk action modifies the UV sector of the theory. In this setup, the dynamics of perturbations on the brahe are studied with details and some confrontation with recent observations are discussed. While the Einstein-Gauss-Bonnet inflation scenario favors only a red spectrum of the scalar perturbation, pure DGP and GBIG inflation models have the capacity to realize the blue spectrum too. In addition, the GBIG inflation scenario in the large field limit requires a smaller number of e-folds than other proposed scenarios in the same situation. For the tensor-to-scalar ratio, the GBIG inflation scenario gives a better 1fit with observationally supported value of R≈ 0.24.

  16. Topological and Geometrical Proprieties of Brane-Worlds

    CERN Document Server

    Monte, Edmundo M

    2011-01-01

    We study the geometrical and topological properties of the bulk (environment space) when we modify the geometry or topology of a brane-world. Through the characterization of a spherically symmetric space-time as a local brane-world immersed into six dimensional pseudo-Euclidean spaces, with different signatures of the bulk, we investigate the existence of a topological difference in the immersed brane-world. In particular the Schwarzschild's brane-world and its Kruskal (or Fronsdal) brane-world extension are examined from point of view of the immersion formalism. We prove that there is a change of signature of the bulk when we consider a local isometric immersion and different topologies of a brane-world in that bulk.

  17. Simple brane-world inflationary models in light of BICEP2

    CERN Document Server

    Okada, Nobuchika

    2014-01-01

    Motivated by the recent CMB $B$-mode observation announced by the BICEP2 collaboration, we study simple inflationary models in the Randall-Sundrum brane-world cosmology. Brane-world cosmological effects alter the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology. In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension, and simple inflationary models which predict small $r$ values in the standard cosmology can yield $r$ values being compatible with the BICEP2 result, $r=0.2^{+0.07}_{-0.05}$. Confirmation of the BICEP2 result and more precise measurements of $n_s$ and $r$ in the near future allow us to constrain the 5-dimensional Planck mass ($M_5$) of the brane-world scenario. We also discuss the post inflationary scenario, namely, reheating of the universe through inflaton decay to the Standard Model particles. When we require the renormalizability of the inflationary models, the inflaton...

  18. Graviton KK resonant mode in the correction of the Newton's law from 6D braneworlds

    CERN Document Server

    Araujo, J C B; Dantas, D M; Almeida, C A S

    2016-01-01

    In this work, we derive an expression for the correction in the Newton's law of gravitation due to the gravitational Kaluza-Klein states in a general thick string-like braneworld scenario in six dimensions. In order to analyze corrections to Newton's law we study the gravity fluctuations in a 3-brane placed in a transverse resolved conifold and use suitable numerical methods to attain the massive spectrum and the corresponding eigenfunctions. Such braneworld model has a resolution parameter which removes the conical singularity. The correction has an exponentially suppressed mass term and depends on the values of the eigenfunctions and warp factors computed at the core peak of the brane. The spectrum is real and monotonically increased, as desired. However, the resolution parameter must assume moderate values to have physically acceptable states. Moreover, the trapped massless mode regains the 4D gravity and it is displaced from the origin, sharing similar profile with the energy density of brane for small va...

  19. Search for passing-through-walls neutrons constrains hidden braneworlds

    Directory of Open Access Journals (Sweden)

    Michaël Sarrazin

    2016-07-01

    Full Text Available In many theoretical frameworks our visible world is a 3-brane, embedded in a multidimensional bulk, possibly coexisting with hidden braneworlds. Some works have also shown that matter swapping between braneworlds can occur. Here we report the results of an experiment – at the Institut Laue-Langevin (Grenoble, France – designed to detect thermal neutron swapping to and from another braneworld, thus constraining the probability p2 of such an event. The limit, p87 in Planck length units.

  20. Braneworld Stars:. Anisotropy Minimally Projected onto the Brane

    Science.gov (United States)

    Ovalle, J.

    2010-04-01

    In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to Einstein's field equations for static and non-uniform braneworld stars with local and non-local bulk terms, is carefully presented. It is shown that this approach allows the generation of a braneworld version for any known general relativistic solution.

  1. Searching Exact Solutions for Compact Stars in Braneworld: a conjecture

    OpenAIRE

    2007-01-01

    In the context of the braneworld, a method to find consistent solutions to Einstein's field equations in the interior of a spherically symmetric, static and non uniform stellar distribution with Weyl stresses is developed. This method, based in the fact that any braneworld stellar solution must have the general relativity solution as a limit, produces a constraint which reduces the degrees of freedom on the brane. Hence the non locality and non closure of the braneworld equations can be overc...

  2. Braneworld Stars: Anisotropy Minimally Projected Onto the Brane

    OpenAIRE

    2009-01-01

    In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to Einstein's field equations for static and non-uniform braneworld stars with local and non-local bulk terms, is carefully presented. It is shown that this approach allows the generation of a braneworld version for any known general relativistic solution.

  3. Search for passing-through-walls neutrons constrains hidden braneworlds

    Science.gov (United States)

    Sarrazin, Michaël; Pignol, Guillaume; Lamblin, Jacob; Pinon, Jonhathan; Méplan, Olivier; Terwagne, Guy; Debarsy, Paul-Louis; Petit, Fabrice; Nesvizhevsky, Valery V.

    2016-07-01

    In many theoretical frameworks our visible world is a 3-brane, embedded in a multidimensional bulk, possibly coexisting with hidden braneworlds. Some works have also shown that matter swapping between braneworlds can occur. Here we report the results of an experiment - at the Institut Laue-Langevin (Grenoble, France) - designed to detect thermal neutron swapping to and from another braneworld, thus constraining the probability p2 of such an event. The limit, p 87 in Planck length units.

  4. Braneworld Stars: Anisotropy Minimally Projected Onto the Brane

    CERN Document Server

    Ovalle, J

    2009-01-01

    In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to Einstein's field equations for static and non-uniform braneworld stars with local and non-local bulk terms, is carefully presented. It is shown that this approach allows the generation of a braneworld version for any known general relativistic solution. As a demonstration, the braneworld version of the Schwarzschild's interior solution is generated using this method.

  5. A 6D standing wave Braneworld

    CERN Document Server

    Sousa, L J S; Almeida, C A S

    2012-01-01

    We constructed a six-dimensional version of the standing wave model with an anisotropic 4-brane generated by a phantom-like scalar field. The model represents a braneworld where the compact (on-brane) dimension is assumed to be sufficiently small in order to describe our universe (hybrid compactification). The proposed geometry of the brane and its transverse manifold is non-static, unlike the majority of braneworld models presented in the literature. Furthermore, we have shown that the zero-mode scalar field is localized around the brane. While in the string-like defect the scalar field is localized on a brane with decreasing warp factor, here it was possible to perform the localization with an increasing warp factor.

  6. Probing Lambda-DGP Braneworld Model

    CERN Document Server

    Ravanpak, A; Fadakar, G F

    2016-01-01

    In this article we study cosmic dynamics in the context of normal branch of DGP braneworld model. Using the current Planck data, we best fit the model and cosmological parameters in non-flat $\\Lambda$DGP. With the transition redshift as a basic variable and statefinder parameters, our result shows that the Universe starts its accelerated expansion phase, slightly earlier than expected in $\\Lambda$CDM cosmology. The result also alleviates the coincidence problem of the $\\Lambda$CDM model.

  7. Braneworld dynamics with the BraneCode

    CERN Document Server

    Martín, J; Frolov, A V; Peloso, M; Kofman, L A; Martin, Johannes; Felder, Gary N.; Frolov, Andrei V.; Peloso, Marco; Kofman, Lev

    2003-01-01

    We give a full nonlinear numerical treatment of time-dependent 5d braneworld geometry, which is determined self-consistently by potentials for the scalar field in the bulk and at two orbifold branes, supplemented by boundary conditions at the branes. We describe the BraneCode, an algorithm which we designed to solve the dynamical equations numerically. We applied the BraneCode to braneworld models and found several novel phenomena of the brane dynamics. Starting with static warped geometry with de Sitter branes, we found numerically that this configuration is often unstable due to a tachyonic mass of the radion during inflation. If the model admits other static configurations with lower values of de Sitter curvature, this effect causes a violent re-structuring towards them, flattening the branes, which appears as a lowering of the 4d effective cosmological constant. Braneworld dynamics can often lead to brane collisions. We found that in the presence of the bulk scalar field, the 5d geometry between colliding...

  8. Glueballs Mass Spectrum in an Inflationary Braneworld Scenario

    CERN Document Server

    Barosi, L; Jesuino, H S; Queiroz, A R

    2010-01-01

    We address the issue of glueball masses in a holographic dual field theory on the boundary of an AdS space deformed by a four-dimensional cosmological constant. These glueballs are related to scalar and tensorial fluctuations of the bulk fields on this space. In the Euclidean AdS4 case the allowed masses are discretized and are related to distinct inflaton masses on a 3-brane with several states of inflation. We then obtain the e-folds number in terms of the glueball masses. In the last part we focus on the Lorentzian dS4 case to focus on the QCD equation of state in dual field theory.

  9. A de Sitter tachyon thick braneworld

    Energy Technology Data Exchange (ETDEWEB)

    Germán, Gabriel; Herrera-Aguilar, Alfredo; Malagón-Morejón, Dagoberto [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apdo. Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Mora-Luna, Refugio Rigel [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, C.P. 58040, Morelia, Michoacán (Mexico); Rocha, Roldão da, E-mail: gabriel@fis.unam.mx, E-mail: aha@fis.unam.mx, E-mail: malagon@ifm.umich.mx, E-mail: rigel@ifm.umich.mx, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Rua Santa Adélia, 166 09210-170, Santo André, SP (Brazil)

    2013-02-01

    Among the multiple 5D thick braneworld models that have been proposed in the last years, in order to address several open problems in modern physics, there is a specific one involving a tachyonic bulk scalar field. Delving into this framework, a thick braneworld with a cosmological background induced on the brane is here investigated. The respective field equations — derived from the model with a warped 5D geometry — are highly non-linear equations, admitting a non-trivial solution for the warp factor and the tachyon scalar field as well, in a de Sitter 4D cosmological background. Moreover, the non-linear tachyonic scalar field, that generates the brane in complicity with warped gravity, has the form of a kink-like configuration. Notwithstanding, the non-linear field equations restricting character does not allow one to easily find thick brane solutions with a decaying warp factor which leads to the localization of 4D gravity and other matter fields. We derive such a thick brane configuration altogether in this tachyon-gravity setup. When analyzing the spectrum of gravity fluctuations in the transverse traceless sector, the 4D gravity is shown to be localized due to the presence of a single zero mode bound state, separated by a continuum of massive Kaluza-Klein (KK) modes by a mass gap. It contrasts with previous results, where there is a KK massive bound excitation providing no clear physical interpretation. The mass gap is determined by the scale of the metric parameter H. Finally, the corrections to Newton's law in this model are computed and shown to decay exponentially. It is in full compliance to corrections reported in previous results (up to a constant factor) within similar braneworlds with induced 4D de Sitter metric, despite the fact that the warp factor and the massive modes have a different form.

  10. Nonuniform Braneworld Stars: AN Exact Solution

    Science.gov (United States)

    Ovalle, J.

    In this paper the first exact interior solution to Einstein's field equations for a static and nonuniform braneworld star with local and nonlocal bulk terms is presented. It is shown that the bulk Weyl scalar U(r) is always negative inside the stellar distribution, and in consequence it reduces both the effective density and the effective pressure. It is found that the anisotropy generated by bulk gravity effect has an acceptable physical behavior inside the distribution. Using a Reissner-Nördstrom-like exterior solution, the effects of bulk gravity on pressure and density are found through matching conditions.

  11. Tolman IV solution in the Randall-Sundrum braneworld

    Science.gov (United States)

    Ovalle, J.; Linares, F.

    2013-11-01

    In the context of the Randall-Sundrum braneworld, the minimal geometric deformation approach is used to generate an analytic interior solution to four-dimensional effective Einstein field equations for a spherically symmetric compact distribution. This solution represents the braneworld version of the well-known Tolman IV solution in general relativity. By using this analytic solution, an exhaustive analysis of the braneworld effects on realistic stellar interiors is developed, finding strong evidence in favor of the hypothesis that compactness is reduced due to bulk effects on stellar configurations.

  12. Tolman IV solution in the Randall-Sundrum Braneworld

    CERN Document Server

    Ovalle, J

    2013-01-01

    In the context of the Randall-Sundrum braneworld, the minimal geometric deformation approach (MGD) is used to generate an exact analytic interior solution to four-dimensional effective Einstein's field equations for a spherically symmetric compact distribution. This solution represents the braneworld version of the well known Tolman IV solution in General Relativity. By using this analytic solution, an exhaustive analysis of the braneworld effects on realistic stellar interiors is developed, finding strong evidences in favor of the hypothesis that compactness is reduced due to bulk effects on stellar configurations.

  13. Brane-world stars and (microscopic) black holes

    CERN Document Server

    Casadio, R

    2012-01-01

    We study stars in the brane-world by employing the principle of minimal geometric deformation and find that brane-world black hole metrics with a tidal charge are consistently recovered in a suitable limit. This procedure allows us to determine the tidal charge as a function of the black hole ADM mass (and brane tension). A minimum mass for semiclassical microscopic black holes can then be derived, with a relevant impact for the description of black hole events at the LHC.

  14. Cosmological solutions and observational constraints on 5-dimensional braneworld cosmology with gravitating Nambu-Goto matching conditions

    CERN Document Server

    Kofinas, Georgios; Xia, Jun-Qing

    2014-01-01

    We investigate the cosmological implications of the recently constructed 5-dimensional braneworld cosmology with gravitating Nambu-Goto matching conditions. Inserting both matter and radiation sectors, we first extract the analytical cosmological solutions. Additionally, we use observational data from Type Ia Supernovae (SNIa) and Baryon Acoustic Oscillations (BAO), along with requirements of Big Bang Nucleosynthesis (BBN), in order to impose constraints on the parameters of the model. We find that the scenario at hand is in very good agreement with observations, and thus a small departure from the standard Randall-Sundrum scenario is allowed.

  15. Braneworld model of dark matter: structure formation

    Science.gov (United States)

    García-Aspeitia, Miguel A.; Magaña, Juan A.; Matos, Tonatiuh

    2012-03-01

    Following a previous work (García-Aspeitia in Gen Rel Grav 43:315-329, 2011), we further study the behavior of a real scalar field in a hidden brane in a configuration of two branes embedded in a five dimensional bulk. We find an expression for the equation of state for this scalar field in the visible brane in terms of the fields of the hidden one. Additionally, we investigated the perturbations produced by this scalar field in the visible brane with the aim to study their dynamical properties. Our results show that if the kinetic energy of the scalar field dominates during the early universe the perturbed scalar field could mimic the observed dynamics for the dark matter in the standard paradigm. Thus, the scalar field dark matter hypothesis in the context of braneworld theory could be an interesting alternative to the nature of dark matter in the Universe.

  16. Anisotropy and inflation in Bianchi I braneworlds

    Energy Technology Data Exchange (ETDEWEB)

    Aguirregabiria, Juan M [Fisika Teorikoa eta Zientziaren Historia Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 Posta Kutxatila, 48080 Bilbao (Spain); Chimento, Luis P [Departamento de FIsica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Lazkoz, Ruth [Fisika Teorikoa eta Zientziaren Historia Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea, 644 Posta Kutxatila, 48080 Bilbao (Spain)

    2004-02-21

    After a more general assumption on the influence of the bulk on the brane, we extend some conclusions by Maartens et al (2001 Phys. Rev. D 63 063509) and Santos et al (2001 Phys. Rev. D 64 063506) on the asymptotic behaviour of Bianchi I braneworlds. As a consequence of the nonlocal anisotropic stresses induced by the bulk, in most of our models, the brane does not isotropize and the nonlocal energy does not vanish in the limit in which the mean radius goes to infinity. We have also found the intriguing possibility that the inflation due to the cosmological constant might be prevented by the interaction with the bulk. We show that the problem for the mean radius can be completely solved in our models, which include as particular cases those in the references above.

  17. Enveloping branes and brane-world singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios; Cotsakis, Spiros [CERN-Theory Division, Department of Physics, Geneva 23 (Switzerland); Klaoudatou, Ifigeneia [University of the Aegean, Research Group of Geometry, Dynamical Systems and Cosmology, Department of Information and Communication Systems Engineering, Samos (Greece)

    2014-12-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well. (orig.)

  18. Evolution of gravitational waves in the high-energy regime of brane-world cosmology

    CERN Document Server

    Hiramatsu, T; Taruya, A; Hiramatsu, Takashi; Koyama, Kazuya; Taruya, Atsushi

    2004-01-01

    We discuss the cosmological evolution of gravitational waves (GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter (AdS_5) bulk spacetime. In a brane-world scenario, the evolution of GWs is affected by the non-standard cosmological expansion and the excitation of the Kaluza-Klein modes (KK-modes), which are significant in the high-energy regime of the universe. We numerically solve the wave equation of GWs in the Poincare coordinates of the AdS_5 spacetime. Using a plausible initial condition from inflation, we find that, while the behavior of GWs in the bulk is sensitive to the transition time from inflation to the radiation dominated epoch, the amplitude of GWs on the brane is insensitive to this time if the transition occurs early enough before horizon re-entry. As a result, the amplitude of GWs is suppressed by the excitation of KK-modes which escape from the brane into the bulk, and the effect may compensate the enhancement of the GWs by the non-standard cosmologica...

  19. Simple brane-world inflationary models — An update

    Science.gov (United States)

    Okada, Nobuchika; Okada, Satomi

    2016-05-01

    In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology. Brane-world cosmological effect alters the inflationary predictions of the spectral index (ns) and the tensor-to-scalar ratio (r) from those obtained in the standard cosmology. In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension. In order to maintain the consistency with the Planck 2015 results for the inflationary predictions in the standard cosmology, we find a lower bound on the five-dimensional Planck mass (M5). On the other hand, the inflationary predictions laying outside of the Planck allowed region can be pushed into the allowed region by the brane-world cosmological effect with a suitable choice of M5.

  20. Brane-world dark stars with solid crust

    CERN Document Server

    Ovalle, Jorge; Casadio, Roberto

    2014-01-01

    The minimal geometric deformation approach is employed to show the existence of brane-world stellar distributions with vacuum Schwarzschild exterior, thus without energy leaking from the exterior of the brane-world star into the extra dimension. The interior satisfies all elementary criteria of physical acceptability for a stellar solution, namely, it is regular at the origin, the pressure and density are positive and decrease monotonically with increasing radius, finally all energy conditions are fulfilled. A very thin solid crust with negative radial pressure separates the interior from the exterior, having a thickness $\\Delta $ inversely proportional to both the brane tension $\\sigma $ and the radius $R$ of the star, i.e. $\\Delta ^{-1}\\sim R\\,\\sigma $. This brane-world star with Schwarzschild exterior would appear dark to a distant observer and be fully compatible with the stringent constraints imposed on stellar parameters by observations of gravitational lensing, orbital evolutions or properties of accre...

  1. Simple brane-world inflationary models: an update

    CERN Document Server

    Okada, Nobuchika

    2015-01-01

    In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology. Brane-world cosmological effect alters the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology. In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension. In order to maintain the consistency with the Planck 2015 results for the inflationary predictions in the standard cosmology, we find a lower bound on the five-dimensional Planck mass. On the other hand, the inflationary predictions laying outside of the Planck allowed region can be pushed into the allowed region by the brane-world cosmological effect.

  2. Magnetized Particle Motion Around Black Hole in Braneworld

    CERN Document Server

    Rahimov, Ozodbek

    2010-01-01

    We investigate the motion of a magnetized particle orbiting around a black hole in braneworld placed in asymptotically uniform magnetic field. The influence of brane parameter on effective potential of the radial motion of magnetized spinning particle around the braneworld black hole using Hamilton-Jacobi formalism is studied. It is found that circular orbits for photons and slowly moving particles may become stable near $r = 3M$. It was argued that the radii of the innermost stable circular orbits are sensitive on the change of brane parameter. Similar discussion without Weil parameter has been considered by de Felice et all in~Ref. \\refcite{rs99,98}.

  3. Brane-world stars and (microscopic) black holes

    Science.gov (United States)

    Casadio, R.; Ovalle, J.

    2012-08-01

    We study stars in the brane-world by employing the principle of minimal geometric deformation and find that brane-world black hole metrics with a tidal charge can be consistently recovered in a suitable limit. This procedure allows us to determine the tidal charge as a function of the ADM mass of the black hole (and brane tension). A minimum mass for semiclassical microscopic black holes can then be derived, with a relevant impact for the description of black hole events at the LHC.

  4. Brane-world stars and (microscopic) black holes

    Energy Technology Data Exchange (ETDEWEB)

    Casadio, R., E-mail: casadio@bo.infn.it [Dipartimento di Fisica, Universita di Bologna, via Irnerio 46, 40126 Bologna (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, via Irnerio 46, 40126 Bologna (Italy); Ovalle, J., E-mail: jovalle@usb.ve [Departamento de Fisica, Universidad Simon Bolivar, Apartado 89000, Caracas 1080A (Venezuela, Bolivarian Republic of)

    2012-08-29

    We study stars in the brane-world by employing the principle of minimal geometric deformation and find that brane-world black hole metrics with a tidal charge can be consistently recovered in a suitable limit. This procedure allows us to determine the tidal charge as a function of the ADM mass of the black hole (and brane tension). A minimum mass for semiclassical microscopic black holes can then be derived, with a relevant impact for the description of black hole events at the LHC.

  5. Constraining the braneworld with gravitational wave observations

    CERN Document Server

    McWilliams, Sean T

    2009-01-01

    Braneworld models containing large extra dimensions may have observable consequences that, if detected, would validate a requisite element of string theory. In the infinite Randall-Sundrum model, the asymptotic AdS radius of curvature of the extra dimension supports a single bound state of the massless graviton on the brane, thereby avoiding gross violations of Newton's law. However, one possible consequence of this model is an enormous increase in the amount of Hawking radiation emitted by black holes. This consequence has been employed by other authors to attempt to constrain the AdS radius of curvature through the observation of black holes. I present two novel methods for constraining the AdS curvature. The first method results from the effect of this enhanced mass loss on the event rate for extreme mass ratio inspirals (EMRIs) detected by the space-based LISA interferometer. The second method results from the observation of an individually resolvable galactic black hole binary with LISA. I show that the ...

  6. Non-minimally coupled bulk scalar fields in sine-Gordon braneworld models

    Science.gov (United States)

    Moazzen, Masoumeh; Ghalenovi, Zahra

    2017-10-01

    In this paper, we investigate localization of bulk scalar fields in two types of five-dimensional braneworld models given by sine-Gordon potentials (SG). The sine-Gordon and Double sine-Gordon (DSG) branes are employed to produce different thick brane setups. In both scenarios, we include the bulk mass and non-minimally coupled terms in the global action and obtain some implications on the volcano-like potentials of the Kaluza-Klein modes associated to the corresponding Schrödinger-like equations. Also, we find that minimally and non-minimally coupled massive bulk scalar fields can be localized on SG and DSG branes if their bulk mass obeys an upper bound. Furthermore, it is shown that at the critical value of the non-minimal coupling constant the bulk scalar field cannot be localized on the branes.

  7. Configurational entropy as a bounding of Gauss-Bonnet braneworld models

    CERN Document Server

    Correa, R A C; Dutra, A de Souza; de Paula, W; Frederico, T

    2016-01-01

    Configurational entropy has been revealed as a reliable method for constraining some parameters of a given model [Phys. Rev. D \\textbf{92} (2015) 126005, Eur. Phys. J. C \\textbf{76} (2016) 100]. In this letter we calculate the configurational entropy in Gauss-Bonnet braneworld models. Our results restrict the range of acceptability of the Gauss-Bonnet scalar values. In this way, the information theoretical measure in Gauss-Bonnet scenarios opens a new window to probe situations where the additional parameters, responsible for the Gauss-Bonnet sector, are arbitrary. We also show that such an approach is very important in applications that include p and Dp-branes and various superstring-motivated theories.

  8. Aspects of Some New Versions of Pilgrim Dark Energy in DGP Braneworld

    CERN Document Server

    Jawad, Abdul; Salako, Ines G; Gulshan, Faiza

    2016-01-01

    The illustration of cosmic acceleration under two interacting dark energy models (pilgrim dark energy with Granda and Oliveros cutoff and its generalized ghost version) in DGP braneworld framework is presented. In the current scenario, the equation of state parameter, deceleration parameter, $\\omega_{D}-\\omega'_{D}$ plane and statefinder diagnosis are investigated. The equation state parameter behave-like phantom era of the universe. The deceleration parameter depicts the accelerated expansion of the universe in both models. The cosmological planes like $\\omega_{D}-\\omega'_{D}$ and statefinder corresponds to $\\Lambda$CDM limit. To end, we remark that our results support to phenomenon of pilgrim dark energy and cosmic acceleration. Also, the results are consistent with observational data.

  9. Tachyon inflation in an AdS braneworld with back-reaction

    CERN Document Server

    Bilic, Neven; Djordjevic, Goran; Milosevic, Milan

    2016-01-01

    We analyze the inflationary scenario based on the tachyon field coupled with the radion of the second Randall-Sundrum model (RSII). The tachyon Lagrangian is derived from the dynamics of a 3-brane moving in the five dimensional bulk. The AdS$_5$ geometry of the bulk is extended to include the radion. Using the Hamiltonian formalism we find four nonlinear field equations supplemented by the modified Friedmann equations of the RSII braneworld cosmology. After a suitable rescaling we reduce the parameters of our model to only one free parameter related to the brane tension and the AdS$_5$ curvature. We solve the equations numerically assuming a reasonably wide range of initial conditions determined by physical considerations. Varying the free parameter and initial conditions we confront our results with the Planck 2015 data.

  10. Randall-Sundrum brane-world in modified gravity

    CERN Document Server

    Nakada, Hiroshi

    2016-01-01

    We modify Randall-Sundrum model of brane-world (with two branes) by adding the scalar curvature squared term in five dimensions. We find that it does not destabilize Randall-Sundrum solution to the hierarchy problem of the Standard Model in particle physics.

  11. Thermodynamic geometry and phase transitions of AdS braneworld black holes

    Science.gov (United States)

    Chaturvedi, Pankaj; Sengupta, Gautam

    2017-02-01

    The thermodynamics and phase transitions of charged RN-AdS and rotating Kerr-AdS black holes in a generalized Randall-Sundrum braneworld are investigated in the framework of thermodynamic geometry. A detailed analysis of the thermodynamics, stability and phase structures in the canonical and the grand canonical ensembles for these AdS braneworld black holes are described. The thermodynamic curvatures for both these AdS braneworld black holes are computed and studied as a function of the thermodynamic variables. Through this analysis we illustrate an interesting dependence of the phase structures on the braneworld parameter for these black holes.

  12. Braneworld effective action An alternative to Kaluza-Klein reduction

    CERN Document Server

    Barvinsky, A O; Rathke, A; Kiefer, C; Barvinsky, Andrei; Kamenshchik, Alexander; Rathke, Andreas; Kiefer, Claus

    2003-01-01

    We construct the braneworld effective action in the two-brane Randall-Sundrum model in a setup alternative to Kaluza-Klein reduction: The action is written as a functional of the two metric and radion fields on the branes. In the low-energy spectrum of the model we find two - one massless and one massive - graviton modes, the mass of the massive mode diverging in the limit of merging branes. Our results confirm a recently proposed model of braneworld inflation with diverging branes. They also suggest the possibility of a new mechanism for a repulsive interbrane potential which can underlie the model of colliding "thick" branes in the Big Crunch/Big Bang transitions in cosmology. Mixing of the obtained massless and massive modes can be interpreted as radion-induced graviton oscillations potentially interesting for gravitational wave astronomy.

  13. General Perturbations for Braneworld Compactifications and the Six Dimensional Case

    CERN Document Server

    Parameswaran, S L; Salvio, A

    2009-01-01

    Our main objective is to study how braneworld models of higher codimension differ from the 5D case and traditional Kaluza-Klein compactifications. We first derive the classical dynamics describing the physical fluctuations in a wide class of models incorporating gravity, non-Abelian gauge fields, the dilaton and two-form potential, as well as 3-brane sources. Next, we use these results to study braneworld compactifications in 6D supergravity, focusing on the bosonic fields in the minimal model; composed of the supergravity-tensor multiplet and the U(1) gauge multiplet whose flux supports the compactification. For unwarped models sourced by positive tension branes, a harmonic analysis allows us to solve the large, coupled, differential system completely and obtain the full 4D spin-2,1 and 0 particle spectra, establishing (marginal) stability and a qualitative behaviour similar to the smooth sphere compactification. We also find interesting results for models with negative tension branes; extra massless Kaluza-...

  14. Newton's law in braneworlds with an infinite extra dimension

    CERN Document Server

    Ito, M

    2002-01-01

    We study the behavior of the four$-$dimensional Newton's law in warped braneworlds. The setup considered here is a $(3+n)$-brane embedded in $(5+n)$ dimensions, where $n$ extra dimensions are compactified and a dimension is infinite. We show that the wave function of gravity is described in terms of the Bessel functions of $(2+n/2)$-order and that estimate the correction to Newton's law. In particular, the Newton's law for $n=1$ can be exactly obtained.

  15. Angular momentum of a brane-world model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper we discuss the properties of the general covariant angular momentum of a fivedimensional brane-world model. Through calculating the total angular momentum of this model, we are able to analyze the properties of the total angular momentum in the inflationary RS model. We show that the space-like components of the total angular momentum of the inflationary RS model are all zero while the others are non-zero, which agrees with the results from ordinary RS model.

  16. Angular Momentum of a Brane-world Model

    CERN Document Server

    Jia, Bei; Zhang, Peng-Ming

    2008-01-01

    In this paper we discuss the properties of the general covariant angular momentum of a five-dimensional brane-world model. Through calculating the total angular momentum of this model, we are able to analyze the properties of the total angular momentum in the inflationary RS model. We show that the space-like components of the total angular momentum of are all zero while the others are non-zero, which agrees with the results from ordinary RS model.

  17. Brane-World Black Holes and Energy-Momentum Vector

    CERN Document Server

    Salti, M; Korunur, M; Aydogdu, Oktay; Korunur, Murat; Salti, Mustafa

    2006-01-01

    The Brane-World black hole models are investigated to evaluate their relative energy and momentum components. We consider Einstein and M{\\o}ller's energy-momentum prescriptions in general relativity, and also perform the calculation of energy-momentum density in M{\\o}ller's tetrad theory of gravity. For the Brane-World black holes we show that although Einstein and M{\\o}ller complexes, in general relativity give different energy relations, they yield the same results for the momentum components. In addition, we also make the calculation of the energy-momentum distribution in teleparallel gravity, and calculate exactly the same energy as that obtained by using M{\\o}ller's energy-momentum prescription in general relativity. This interesting result supports the viewpoint of Lessner that the M{\\o}ller energy-momentum complex is a powerful concept for the energy and momentum. We also give five different examples of Brane-World black holes and find the energy distributions associated with them. The result calculate...

  18. Searching Exact Solutions for Compact Stars in Braneworld:. a Conjecture

    Science.gov (United States)

    Ovalle, J.

    In the context of the braneworld, a method to find consistent solutions to Einstein's field equations in the interior of a spherically symmetric, static and non-uniform stellar distribution with Weyl stresses is developed. This method, based on the fact that any braneworld stellar solution must have the general relativity solution as a limit, produces a constraint which reduces the degrees of freedom on the brane. Hence the nonlocality and non-closure of the braneworld equations can be overcome. The constraint found is physically interpreted as a necessary condition to regain general relativity, and a particular solution for it is used to find an exact and physically acceptable analytical internal solution to no-uniform stellar distributions on the brane. It is shown that such an exact solution is possible due to the fact that bulk corrections to pressure, density and a metric component are a null source of anisotropic effects on the brane. A conjecture is proposed regarding the possibility of finding physically relevant exact solutions to non-uniform stellar distributions on the brane.

  19. On localization of universal scalar fields in a tachyonic de Sitter thick braneworld

    CERN Document Server

    Diaz-Furlong, Alfonso; Linares, Roman; Mora-Luna, Refugio Rigel; Morales-Tecotl, Hugo A

    2014-01-01

    Braneworld models may yield interesting effects ranging from high-energy physics to cosmology, or even some low-energy physics. Their mode structure modifies standard results in these physical realms that can be tested and used to set bounds on the models parameters. Now, to define braneworld deviations from standard 4D physics, a notion of matter and gravity localization on the brane is crucial. In this work we investigate the localization of universal massive scalar fields in a de Sitter thick tachyonic braneworld generated by gravity coupled to a tachyonic bulk scalar field. This braneworld possesses a 4D de Sitter induced metric and is asymptotically flat despite the presence of a negative bulk cosmological constant, a novel and interesting peculiarity that contrasts with previously known models. Universal scalar fields can be localized in this expanding braneworld if their bulk mass obeys an upper bound, otherwise they delocalize: The dynamics of the scalar field is governed by a Schroedinger equation wi...

  20. String Versus Einstein Frame in AdS/CFT Induced Quantum Dilatonic Brane-World Universe

    CERN Document Server

    Nojiri, S; Odintsov, S D; Tkach, V I; Nojiri, Shin'ichi; Obregon, Octavio; Odintsov, Sergei D.; Tkach, Vladimir I.

    2001-01-01

    AdS/CFT induced quantum dilatonic brane-world where 4d boundary is flat or de Sitter (inflationary) or Anti-de Sitter brane is considered. The classical brane tension is fixed but boundary QFT produces the effective brane tension via the account of corresponding conformal anomaly induced effective action. This results in inducing of brane-worlds in accordance with AdS/CFT set-up as warped compactification. The explicit, independent construction of quantum induced dilatonic brane-worlds in two frames: string and Einstein one is done. It is demonstrated their complete equivalency for all quantum cosmological brane-worlds under discussion, including several examples of classical brane-world black holes. This is different from quantum corrected 4d dilatonic gravity where de Sitter solution exists in Einstein but not in Jordan (string) frame. The role of quantum corrections on massive graviton perturbations around Anti-de Sitter brane is briefly discussed.

  1. Low-Energy Brane-World Effective Actions and Partial Supersymmetry Breaking

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Matthias

    2003-03-18

    As part of a programme for the general study of the low-energy implications of supersymmetry breaking in brane-world scenarios, we study the nonlinear realization of supersymmetry which occurs when breaking N = 2 to N = 1 supergravity. We consider three explicit realizations of this supersymmetry breaking pattern, which correspond to breaking by one brane, by one antibrane or by two (or more) parallel branes. We derive the minimal field content, the effective action and supersymmetry transformation rules for the resulting N = 1 theory perturbatively in powers of {kappa} = 1/M{sub Planck}. We show that the way the massive gravitino and spin-1 fields assemble into N = 1 multiplets implies the existence of direct brane-brane contact interactions at order {Omicron}({kappa}). This result is contrary to the {Omicron}({kappa}{sup 2}) predicted by the sequestering scenario but in agreement with recent work of Anisimov et al. Our low-energy approach is model independent and is a first step towards determining the low-energy implications of more realistic brane models which completely break all supersymmetries.

  2. Linearized gravity in flat braneworlds with anisotropic brane tension

    CERN Document Server

    Ito, M

    2002-01-01

    We study the four-dimensional gravitational fluctuation on anisotropic brane tension embedded in braneworlds with vanishing bulk cosmological constant. In this setup, warp factors have two types (A and B) and we point out that the two types correspond to positive and negative tension brane, respectively. We show that volcano potential in the model of type A has singularity and the usual Newton's law is reproduced by the existence of normalizable zero mode. While, in the case of type B, the effective Planck scale is infinite so that there is no normalizable zero mode.

  3. A Compact Codimension Two Braneworld with Precisely One Brane

    CERN Document Server

    Akerblom, Nikolas

    2010-01-01

    Building on earlier work on football shaped extra dimensions, we construct a compact codimension two braneworld with precisely one brane. The two extra dimensions topologically represent a 2-torus which is stabilized by a bulk cosmological constant and magnetic flux. The torus has positive constant curvature almost everywhere, except for a single conical singularity at the location of the brane. In contradistinction to the football shaped case, there is no fine-tuning required for the brane tension. We also present some plausibility arguments why the model should not suffer from serious stability issues.

  4. Dark matter relic density in Gauss-Bonnet braneworld cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Michael T.; Whittingham, Ian B., E-mail: Michael.Meehan@my.jcu.edu.au, E-mail: Ian.Whittingham@jcu.edu.au [College of Science, Technology and Engineering, James Cook University, 1 James Cook Dr., Townsville 4811 (Australia)

    2014-12-01

    The relic density of symmetric and asymmetric dark matter in a Gauss-Bonnet (GB) modified Randall-Sundrum (RS) type II braneworld cosmology is investigated. The existing study of symmetric dark matter in a GB braneworld (Okada and Okada, 2009) found that the expansion rate was reduced compared to that in standard General Relativity (GR), thereby delaying particle freeze-out and resulting in relic abundances which are suppressed by up to O(10{sup −2}). This is in direct contrast to the behaviour observed in RS braneworlds where the expansion rate is enhanced and the final relic abundance boosted. However, this finding that relic abundances are suppressed in a GB braneworld is based upon a highly contrived situation in which the GB era evolves directly into a standard GR era, rather than passing through a RS era as is the general situation. This collapse of the RS era requires equating the mass scale m{sub α} of the GB modification and the mass scale m{sub σ} of the brane tension. However, if the GB contribution is to be considered as the lowest order correction from string theory to the RS action, we would expect m{sub α} > m{sub σ}. We investigate the effect upon the relic abundance of choosing more realistic values for the ratio R{sub m} ≡ m{sub α}/m{sub σ} and find that the relic abundance can be either enhanced or suppressed by more than two orders of magnitude. However, suppression only occurs for a small range of parameter choices and, overwhelmingly, the predominant situation is that of enhancement as we recover the usual Randall-Sundrum type behaviour in the limit R{sub m} >> 1. We use the latest observational bound Ω{sub DM}h{sup 2} = 0.1187 ± 0.0017 to constrain the various model parameters and briefly discuss the implications for direct/indirect dark matter detection experiments as well as dark matter particle models.

  5. Inflation with hyperbolic potential in the braneworld model

    Indian Academy of Sciences (India)

    Dilip Paul; Bikash Chandra Paul; Xin-He Meng

    2009-05-01

    In this paper we study inflationary dynamics with a scalar field in an inverse coshyperbolic potential in the braneworld model. We note that a sufficient inflation may be obtained with the potential considering slow-roll approximation in the high energy limit. We determine the minimum values of the initial inflaton field required to obtain sufficient inflation and also determine the relevant inflationary parameters. The numerical values of spectral index of the scalar perturbation spectrum are determined by varying the number of e-foldings for different initial values of the inflaton field. The result obtained here is in good agreement with the current observational limits.

  6. Non-uniform Braneworld Stars: an Exact Solution

    CERN Document Server

    Ovalle, J

    2008-01-01

    The first exact interior solution to Einstein's field equations for a static and non-uniform braneworld star with local and non-local bulk terms is presented. It is shown that the bulk Weyl scalar ${\\cal U}(r)$ is always negative inside the stellar distribution, in consequence it reduces both the effective density and the effective pressure. It is found that the anisotropy generated by bulk gravity effect has an acceptable physical behaviour inside the distribution. Using a Reissner-N\\"{o}rdstrom-like exterior solution, the effects of bulk gravity on pressure and density are found through matching conditions.

  7. A standing wave braneworld and associated Sturm-Liouville problem

    CERN Document Server

    Gogberashvili, Merab; Malagon-Morejon, Dagoberto

    2010-01-01

    We present a consistent derivation of the recently proposed 5D standing wave braneworld generated by gravity coupled to a phantom-like scalar field by introducing an energy-momentum tensor on the brane with different tensions along different space-time directions and explicitly solve the corresponding junction conditions. We also analyze the Sturm-Liouville problem associated to the correct localization condition of the transverse to the brane metric and scalar fields. It is shown that this condition restricts the physically meaningful space of solutions for the localization of the fluctuations of the model.

  8. Tachyon and Quintessence Brane-World Universe

    CERN Document Server

    Chimento, Luis P; Kremer, Gilberto M; Richarte, Martin G

    2009-01-01

    Using tachyon or quintessence fields along with a barotropic fluid on the brane we examine the different cosmological stages in a Friedmann-Robertson-Walker(FRW) universe, from the first radiation scenario to the later era dominated by cosmic string networks. We introduce a new algorithm to generalize previous works on exact solutions and apply it to study tachyon and quintessence fields localized on the brane and study the low and high energy regimes. We show that the tachyon and quintessence fields are driven by an inverse power law potential. Finally, we find several simples exacts solutions for tachyon and/or quintessence fields.

  9. Can Effective Field Theory of inflation generate large tensor-to-scalar ratio within Randall Sundrum single braneworld?

    CERN Document Server

    Choudhury, Sayantan

    2015-01-01

    In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall Sundrum (RS) single braneworld scenario in a model independent fashion. By explicit computation I show that the effective field theory prescription of brane inflation within RS single brane setup is consistent with sub-Planckian excursion of the inflaton field, which will further generate large value of tensor-to-scalar ratio, provided the energy density for inflaton degrees of freedom is high enough compared to the brane tension in high energy regime. Finally, I mention the stringent theoretical constraint on positive brane tension, cut-off of the quantum gravity scale and bulk cosmological constant to get sub-Planckian field excursion along with large tensor-to-scalar ratio as recently observed by BICEP2 or at least generates the tensor-to-scalar ratio consistent with the upper bound of Planck.

  10. Estimation of length scale of RS II-$p$ braneworld model through perturbations in Helium's atom ground state energy

    CERN Document Server

    Garrido, Nephtali

    2012-01-01

    We put to the test an effective three-dimensional electrostatic potential, obtained effectively by considering an electrostatic source inside a (5+$p$)-dimensional braneworld scenario with $p$ compact and one infinite spacial extra dimensions in the RS II-$p$ model, for $p=1$ and $p=2$. This potential is regular at the source and matches the standard Coulomb potential outside a neighborhood. We use variational and perturbative approximation methods to calculate corrections to the ground energy of the Helium atom modified by this potential, by making use of a 6 and 39-parameter trial wave function of Hylleraas type for the ground state. These corrections to the ground-state energy are compared with experimental data for Helium atom in order to set bounds for the extra dimensions length scale. We find that these bounds are less restrictive than the ones obtained by Morales et. al. through a calculation using the Lamb shift in Hydrogen.

  11. Holographic dark energy in the DGP braneworld with GO cutoff

    CERN Document Server

    Ghaffari, S; Sheykhi, A

    2015-01-01

    We consider the holographic dark energy (HDE) model in the framework of DGP braneworld with Granda-Oliveros infrared (IR) cutoff, $L=(\\alpha \\dot{H}+\\beta H^2)^{-1/2}$. With this choice for IR cutoff, we are able to derive evolution of the cosmological parameters such as the equation of state and the deceleration parameters, $w$ and $q$, as the functions of the redshift parameter $z$. As far as we know, most previous models of HDE presented in the literatures, do not gives analytically $\\omega=\\omega(z)$ and $q=q(z)$. We plot the evolution of these parameters versus $z$ and discuss that the results are compatible with the recent observations. With suitably choosing the parameters, this model can exhibit a transition from deceleration to the acceleration around $z\\approx 0.6$. Then, we suggest a correspondence between the quintessence and tachyon scalar fields and HDE in the framework of DGP braneworld. This correspondence allows us to reconstruct the evolution of the scalar fields and the scalar potentials. W...

  12. Quasinormal frequencies of black hole in the braneworld

    Science.gov (United States)

    Toshmatov, Bobir; Stuchlík, Zdeněk; Schee, Jan; Ahmedov, Bobomurat

    2016-06-01

    We study scalar, electromagnetic, axial, and polar gravitational perturbations of the four-dimensional Reissner-Nordström-like black holes with a tidal charge in the Randall-Sundrum braneworld in the first approximation when the tidal perturbations are not taken into account. The quasinormal modes of these perturbations have been studied in both normal and eikonal regimes. Calculations have shown that the black holes on the Randall-Sundrum brane are stable against all kinds of perturbations. Moreover, we determine the greybody factor, giving transmission and reflection of the scattered waves through the effective potentials. It has been shown that the scalar perturbative fields are the most favorite to reflect the wave as compared to the other fields. With increasing value of the tidal charge, the ability of the all perturbative potentials to reflect the waves decreases. Our calculations in low- and high-frequency regimes have shown that black holes on the braneworld always have a bigger absorption cross section of massless scalar waves than the Schwarzschild and standard Reissner-Nordström black holes.

  13. A de Sitter tachyon thick braneworld and gravity localization

    CERN Document Server

    German, Gabriel; Malagon-Morejon, Dagoberto; Mora-Luna, Refugio Rigel; da Rocha, Roldao

    2013-01-01

    Among the multiple 5D thick braneworld models that have been proposed in the last years in order to address several open problems in modern physics, there is one that involves a tachyonic bulk scalar field. In this framework we study a thick braneworld with a cosmological background induced on the brane. It turns out that the field equations derived from the model with a warped 5D geometry are highly non-linear equations that admit a non-trivial solution for the warp factor and the tachyon scalar field with a de Sitter 4D cosmological background. Moreover, the non-linear tachyonic scalar field, that generates the brane in complicity with warped gravity, has the form of a kink-like configuration. However, the non-linear field equations' restricting character does not allow one to easily find thick brane solutions with a decaying warp factor which leads to the localization of 4D gravity and other matter fields. We manage to obtain such a thick brane configuration in this tachyon-gravity setup. When analyzing th...

  14. General perturbations for braneworld compactifications and the six dimensional case

    Energy Technology Data Exchange (ETDEWEB)

    Parameswaran, S.L. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Randjbar-Daemi, S. [International Center for Theoretical Physics, Trieste (Italy); Salvio, A. [EPFL, Lausanne (Switzerland). Inst. de Theorie des Phenomenes Physiques]|[Universitat Autonoma de Barcelona, Bellaterra (Spain). IFAE

    2009-02-15

    Our main objective is to study how braneworld models of higher codimension differ from the 5D case and traditional Kaluza-Klein compactifications. We first derive the classical dynamics describing the physical fluctuations in a wide class of models incorporating gravity, non-Abelian gauge fields, the dilaton and two-form potential, as well as 3-brane sources. Next, we use these results to study braneworld compactifications in 6D supergravity, focusing on the bosonic fields in the minimal model; composed of the supergravity-tensor multiplet and the U(1) gauge multiplet whose flux supports the compactification. For unwarped models sourced by positive tension branes, a harmonic analysis allows us to solve the large, coupled, differential system completely and obtain the full 4D spin-2,1 and 0 particle spectra, establishing (marginal) stability and a qualitative behaviour similar to the smooth sphere compactification. We also find interesting results for models with negative tension branes; extra massless Kaluza-Klein vector fields can appear in the spectra, beyond those expected from the isometries in the internal space. These fields imply an enhanced gauge symmetry in the low energy 4D effective theory obtained by truncating to the massless sector, which is explicitly broken as higher modes are excited, until the full 6D symmetries are restored far above the Kaluza-Klein scale. Remarkably, the low energy effective theory does not seem to distinguish between a compactification on a smooth sphere and these singular, deformed spheres. (orig.)

  15. Comments on Brane-World Black Holes and Energy-Momentum Vector

    CERN Document Server

    Nashed, Gamal Gergess Lamee

    2007-01-01

    We show that the energy distribution of the brane-world black holes given by Salti et al. in the context of teleparallel theory is not right. We give the correct formula of energy of those black hole.

  16. Brane-world stars from minimal geometric deformation, and black holes

    CERN Document Server

    Casadio, Roberto

    2012-01-01

    We build analytical models of spherically symmetric stars in the brane-world, in which the external space-time contains both an ADM mass and a tidal charge. In order to determine the interior geometry, we apply the principle of minimal geometric deformation, which allows one to map General Relativistic solutions to solutions of the effective four-dimensional brane-world equations. We further restrict our analysis to stars with a radius linearly related to the total General Relativistic mass, and obtain a general relation between the latter, the brane-world ADM mass and the tidal charge. In these models, the value of the star's radius can then be taken to zero smoothly, thus obtaining brane-world black hole metrics with a tidal charge solely determined by the mass of the source and the brane tension. General conclusions regarding the minimum mass for semiclassical black holes will also be drawn.

  17. Gravitational Kaluza-Klein modes in the String-Cigar Braneworld

    CERN Document Server

    Veras, D F S; Cruz, W T; Almeida, C A S

    2014-01-01

    In this work the gravitational Kaluza-Klein (KK) modes are analysed on string-like braneworlds in six dimensions, namely the thin string-like Gherghetta-Shaposhnikov (GS) and the thick string-cigar model. We find a new massless mode in both modes satisfying the respective Schroedinger equation. By means of numerical analysis for both models, a complete graviton spectrum and eigenfunctions is attained. Besides the linear regime, the KK spectrum exhibits a decreasing behavior with an asymmetric mass gap with respect to the massless mode. The discontinuity is bigger in the GS model, and it is invariant upon the geometrical flow. A massive mode is obtained in the GS model with a tiny mass which does not match in any regime. It turns out that in the string-cigar model, the core brane structure smoothes and amplifies the KK modes near the brane. Further, the presence of a potential well allows the existence of resonant massive gravitons for small masses in the string-cigar scenario.

  18. Heun equation in a 5D sine-Gordon brane-world model with dilaton

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, M.S.; Christiansen, H. [Universidade Estadual do Ceara (GFT/UECE), CE (Brazil). Grupo de Fisica Teorica

    2011-07-01

    Full text: In a brane-world scenario we find the propagation modes of the gauge field in a five-dimensional space-time. We adopt warping factors of the Randall-Sundrum type which are appropriate to regularize the hierarchy problem without imposing finite compactified extra dimensions. The existence and localization of gauge particles in the ordinary four-dimensional world is studied in detail on a thick brane derived out from the equations of motion of an action with a sine-Gordon potential contribution. Maxwell zero modes together with torsion effective fields are then obtained in a gravity-dilaton background inspired in close string theories. The dilaton plays a crucial role in order that the gauge field gets localized in a conformally invariant context. Kaluza-Klein massive states are also computed and, depending on certain parameters like dilaton coupling constant and asymptotic curvature, we are able to do it fully analytically. In a general approach we find that the solutions are of the Heun type. In some specific cases we can show that the Heun general solutions can be transformed into hypergeometric functions. In others, confluent Heun solutions can be transformed into simpler functions like Mathieu functions. Exact mass spectra are found in several cases. In others, we performed numerical calculations that show a well behaved phenomenology as well. In all the cases, Kaluza-Klein modes are strongly suppressed on the brane in the effective four-dimensional theory. (author)

  19. Coulomb's law corrections and fermion field localization in a tachyonic de Sitter thick braneworld

    Science.gov (United States)

    Cartas-Fuentevilla, Roberto; Escalante, Alberto; Germán, Gabriel; Herrera-Aguilar, Alfredo; Rigel Mora-Luna, Refugio

    2016-05-01

    Following recent studies which show that it is possible to localize gravity as well as scalar and gauge vector fields in a tachyonic de Sitter thick braneworld, we investigate the solution of the gauge hierarchy problem, the localization of fermion fields in this model, the recovering of the Coulomb law on the non-relativistic limit of the Yukawa interaction between bulk fermions and gauge bosons localized in the brane, and confront the predicted 5D corrections to the photon mass with its upper experimental/observational bounds, finding the model physically viable since it passes these tests. In order to achieve the latter aims we first consider the Yukawa interaction term between the fermionic and the tachyonic scalar fields MF(T)ΨΨ̅ in the action and analyze four distinct tachyonic functions F(T) that lead to four different structures of the respective fermionic mass spectra with different physics. In particular, localization of the massless left-chiral fermion zero mode is possible for three of these cases. We further analyze the phenomenology of these Yukawa interactions among fermion fields and gauge bosons localized on the brane and obtain the crucial and necessary information to compute the corrections to Coulomb's law coming from massive KK vector modes in the non-relativistic limit. These corrections are exponentially suppressed due to the presence of the mass gap in the mass spectrum of the bulk gauge vector field. From our results we conclude that corrections to Coulomb's law in the thin brane limit have the same form (up to a numerical factor) as far as the left-chiral massless fermion field is localized on the brane. Finally we compute the corrections to the Coulomb's law for an arbitrarily thick brane scenario which can be interpreted as 5D corrections to the photon mass. By performing consistent estimations with brane phenomenology, we found that the predicted corrections to the photon mass, which are well bounded by the experimentally observed or

  20. Coulomb’s law corrections and fermion field localization in a tachyonic de Sitter thick braneworld

    Energy Technology Data Exchange (ETDEWEB)

    Cartas-Fuentevilla, Roberto; Escalante, Alberto [Instituto de Física, Benemérita Universidad Autónoma de Puebla,Apdo. postal J-48, 72570 Puebla, Pue. (Mexico); Germán, Gabriel [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apdo. Postal 48-3, 62251 Cuernavaca, Morelos (Mexico); Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road,Oxford, OX1 3NP (United Kingdom); Herrera-Aguilar, Alfredo [Instituto de Física, Benemérita Universidad Autónoma de Puebla,Apdo. postal J-48, 72570 Puebla, Pue. (Mexico); Institutode Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo,Edificio C-3, Ciudad Universitaria, CP 58040, Morelia, Michoacán (Mexico); Mora-Luna, Refugio Rigel [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,Apdo. Postal 48-3, 62251 Cuernavaca, Morelos (Mexico)

    2016-05-11

    Following recent studies which show that it is possible to localize gravity as well as scalar and gauge vector fields in a tachyonic de Sitter thick braneworld, we investigate the solution of the gauge hierarchy problem, the localization of fermion fields in this model, the recovering of the Coulomb law on the non-relativistic limit of the Yukawa interaction between bulk fermions and gauge bosons localized in the brane, and confront the predicted 5D corrections to the photon mass with its upper experimental/observational bounds, finding the model physically viable since it passes these tests. In order to achieve the latter aims we first consider the Yukawa interaction term between the fermionic and the tachyonic scalar fields MF(T)ΨΨ-bar in the action and analyze four distinct tachyonic functions F(T) that lead to four different structures of the respective fermionic mass spectra with different physics. In particular, localization of the massless left-chiral fermion zero mode is possible for three of these cases. We further analyze the phenomenology of these Yukawa interactions among fermion fields and gauge bosons localized on the brane and obtain the crucial and necessary information to compute the corrections to Coulomb’s law coming from massive KK vector modes in the non-relativistic limit. These corrections are exponentially suppressed due to the presence of the mass gap in the mass spectrum of the bulk gauge vector field. From our results we conclude that corrections to Coulomb’s law in the thin brane limit have the same form (up to a numerical factor) as far as the left-chiral massless fermion field is localized on the brane. Finally we compute the corrections to the Coulomb’s law for an arbitrarily thick brane scenario which can be interpreted as 5D corrections to the photon mass. By performing consistent estimations with brane phenomenology, we found that the predicted corrections to the photon mass, which are well bounded by the experimentally

  1. Thermodynamics of viscous dark energy in an RSII braneworld

    CERN Document Server

    Setare, M R

    2011-01-01

    We show that for an RSII braneworld filled with interacting viscous dark energy and dark matter, one can always rewrite the Friedmann equation in the form of the first law of thermodynamics, $dE=T_hdS_h+WdV$, at apparent horizon. In addition, the generalized second law of thermodynamics can fulfilled in a region enclosed by the apparent horizon on the brane for both constant and time variable 5-dynamical Newton's constant $G_5$. These results hold regardless of the specific form of the dark energy. Our study further support that in an accelerating universe with spatial curvature, the apparent horizon is a physical boundary from the thermodynamical point of view.

  2. BRANECODE: A Program for Simulations of Braneworld Dynamics

    CERN Document Server

    Martin, Johannes; Frolov, Andrei V; Kofman, Lev; Peloso, Marco; Martin, Johannes; Felder, Gary N.; Frolov, Andrei V.; Kofman, Lev; Peloso, Marco

    2004-01-01

    We describe an algorithm and a C++ implementation that we have written and made available for calculating the fully nonlinear evolution of 5D braneworld models with scalar fields. Bulk fields allow for the stabilization of the extra space. However, they complicate the dynamics of the system, so that analytic calculations (performed within an effective 4D theory) are typically only reliable close to stabilized configurations or when the evolution of the extra space is negligible. In the general case, a numerical study of the 5D equations is necessary, and the algorithm and code we describe are the first ones designed for this task. The program and its full documentation are available on the Web at http://www.cita.utoronto.ca/~jmartin/BRANECODE/. In this paper we provide a brief overview of what the program does and how to use it.

  3. Cosmological Constraints on DGP Braneworld Gravity with Brane Tension

    CERN Document Server

    Lombriser, Lucas; Fang, Wenjuan; Seljak, Uros

    2009-01-01

    We perform a Markov Chain Monte Carlo analysis of the self-accelerating and normal branch of Dvali-Gabadadze-Porrati braneworld gravity. By adopting a parameterized post-Friedmann description of gravity, we utilize all of the cosmic microwave background data, including the largest scales, and its correlation with galaxies in addition to the geometrical constraints from supernovae distances and the Hubble constant. We find that on both branches brane tension or a cosmological constant is required at high significance with no evidence for the unique Dvali-Gabadadze-Porrati modifications. The cross-over scale must therefore be substantially greater than the Hubble scale H_0 r_c > 3 and 3.5 at the 95% CL with and without uncertainties from spatial curvature. With spatial curvature, the limit from the normal branch is substantially assisted by the galaxy cross-correlation which highlights its importance in constraining infrared modifications to gravity.

  4. Quasinormal frequencies of black hole in the braneworld

    CERN Document Server

    Toshmatov, Bobir; Schee, Jan; Ahmedov, Bobomurat

    2016-01-01

    We have studied scalar, electromagnetic and gravitational perturbations of the four-dimensional Reissner-Nordstr\\"{o}m-like black holes with a \\textit{tidal charge} in the Randall-Sundrum braneworld. The quasinormal modes of these scalar, electromagnetic, as well as axial and polar gravitational perturbations, have been studied in both normal and eikonal regimes. Calculations have shown that the black holes on the Randall-Sundrum brane are stable against scalar, electromagnetic and gravitational perturbations. Moreover, we determine the grey body factor, giving transmission and reflection of the scattered waves through the scalar, electromagnetic and gravitational effective potentials. It has been shown that the scalar perturbative fields are the most favorite to the reflected as compared to the latter. With increasing value of the tidal charge ability of the all perturbative potentials to reflect the waves decreases. Our calculations in low- and high-frequency regimes have shown that black holes on the brane...

  5. Searching Exact Solutions for Compact Stars in Braneworld: a conjecture

    CERN Document Server

    Ovalle, J

    2007-01-01

    In the context of the braneworld, a spherically symmetric, static and nonhomogeneous stellar distribution with local and non-local bulk terms is studied. Using a toy solution, it is shown how the general relativistic limit could be lost while a solution is being generated on the brane. The source of this problem is clearly identified and solved by a general solution where a constraint can be identified. This constraint is physically interpreted as a necessary condition to regain general relativity, and a particular solution for it is used to find an exact analytical internal solution to no-uniform stellar distributions on the brane. It is shown that such an exact solution is possible due to the fact that bulk corrections to pressure, density and a metric component are a null source of anisotropic effects on the brane. A conjecture is proposed about the possibility of finding physically relevant exact solutions to non-uniform stellar distributions on the brane.

  6. 5-dimensional braneworld with gravitating Nambu-Goto matching conditions

    Science.gov (United States)

    Kofinas, Georgios; Zarikas, Vasilios

    2014-12-01

    We continue the investigation of a recent proposal on alternative matching conditions for self-gravitating defects which generalize the standard matching conditions. The reasoning for this study is the need for consistency of the various codimension defects and the existence of a meaningful equation of motion at the probe limit, things that seem to lack from the standard approach. These matching conditions arise by varying the brane-bulk action with respect to the brane embedding fields (and not with respect to the bulk metric at the brane position) in a way that takes into account the gravitational back-reaction of the brane to the bulk. They always possess a Nambu-Goto probe limit and any codimension defect is seemingly consistent for any second order bulk gravity theory. Here, we consider in detail the case of a codimension-1 brane in five-dimensional Einstein gravity, derive the generic alternative junction conditions and find the Z2-symmetric braneworld cosmology, as well as its bulk extension. Compared to the standard braneworld cosmology, the new one has an extra integration constant which accounts for the today matter and dark energy contents, therefore, there is more freedom for accommodating the observed cosmic features. One branch of the solution possesses the asymptotic linearized LFRW regime. We have constrained the parameters so that to have a recent passage from a long deceleration era to a small today acceleration epoch and we have computed the age of the universe, consistent with current data, and the time-varying dark energy equation of state. For a range of the parameters it is possible for the presented cosmology to provide a large acceleration in the high energy regime.

  7. Self-Consistent Cosmological Simulations of DGP Braneworld Gravity

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Fabian [Univ. of Chicago, IL (United States). Kavli Inst. for Cosmological Physics (KICP)

    2009-09-01

    We perform cosmological N-body simulations of the Dvali-Gabadadze-Porrati braneworld model, by solving the full non-linear equations of motion for the scalar degree of freedom in this model, the brane bending mode. While coupling universally to matter, the brane-bending mode has self-interactions that become important as soon as the density field becomes non-linear. These self-interactions lead to a suppression of the field in high-density environments, and restore gravity to General Relativity. The code uses a multi-grid relaxation scheme to solve the non-linear field equation in the quasi-static approximation. We perform simulations of a flat self-accelerating DGP model without cosmological constant. However, the type of non-linear interactions of the brane-bending mode, which are the focus of this study, are generic to a wide class of braneworld cosmologies. The results of the DGP simulations are compared with standard gravity simulations assuming the same expansion history, and with DGP simulations using the linearized equation for the brane bending mode. This allows us to isolate the effects of the non-linear self-couplings of the field which are noticeable already on quasi-linear scales. We present results on the matter power spectrum and the halo mass function, and discuss the behavior of the brane bending mode within cosmological structure formation. We find that, independently of CMB constraints, the self-accelerating DGP model is strongly constrained by current weak lensing and cluster abundance measurements.

  8. Dilatonic Brane-World Black Holes, Gravity Localization and Newton Constant

    CERN Document Server

    Nojiri, S; Odintsov, S D; Ogushi, S; Nojiri, Shin'ichi; Obregon, Octavio; Odintsov, Sergei D.; Ogushi, Sachiko

    2000-01-01

    The family of brane-world solutions of d+1-dimensional dilatonic gravity is presented. It includes flat brane with small cosmological constant and (anti) de Sitter brane, dilatonic brane-world black holes (Schwarzschild-(anti-) de Sitter, Kerr, etc). Gravitational and dilatonic perturbations around such branes are found. It is shown that near dilatonic brane-world black hole the gravity may be localized in a standard form. The brane corrections to Newton law are estimated. The proposal to take into account the dilaton coupled brane matter quantum effects is made. The corresponding effective action changes the structure of 4d de Sitter wall. RG flow of four-dimensional Newton constant in IR and UV is briefly discussed.

  9. Probing the braneworld hypothesis with a neutron-shining-through-a-wall experiment

    Science.gov (United States)

    Sarrazin, Michaël; Pignol, Guillaume; Lamblin, Jacob; Petit, Fabrice; Terwagne, Guy; Nesvizhevsky, Valery V.

    2015-04-01

    The possibility for our visible world to be a 3-brane embedded in a multidimensional bulk is at the heart of many theoretical edifices in high-energy physics. Probing the braneworld hypothesis is thus a major experimental challenge. Following recent theoretical works showing that matter swapping between braneworlds can occur, we propose a neutron-shining-through-a-wall experiment. We first show that an intense neutron source such as a nuclear reactor core can induce a hidden neutron flux in an adjacent hidden braneworld. We then describe how a low-background detector can detect neutrons arising from the hidden world and quantify the expected sensitivity to the swapping probability. As a proof of concept, a constraint is derived from previous experiments.

  10. Brane-world stars with a solid crust and vacuum exterior

    Science.gov (United States)

    Ovalle, Jorge; Gergely, László Á.; Casadio, Roberto

    2015-02-01

    The minimal geometric deformation approach is employed to show the existence of brane-world stellar distributions with a vacuum Schwarzschild exterior, thus without energy leaking from the exterior of the brane-world star into the extra dimension. The interior satisfies all the elementary criteria of physical acceptability for a stellar solution, namely, it is regular at the origin, the pressure and density are positive and decrease monotonically with increasing radius, and all energy conditions are fulfilled. A very thin solid crust with negative radial pressure separates the interior from the exterior, having a thickness Δ inversely proportional to both the brane tension σ and the radius R of the star, i.e. {{Δ }-1}˜ Rσ . This brane-world star with Schwarzschild exterior would appear only thermally radiating to a distant observer and be fully compatible with the stringent constraints imposed on stellar parameters by observations of gravitational lensing, orbital evolutions or properties of accretion disks.

  11. Thick brane isotropization in the 5D anisotropic standing wave braneworld model

    CERN Document Server

    Gogberashvili, Merab; Malagon-Morejon, Dagoberto; Mora-Luna, Refugio Rigel; Nucamendi, Ulises

    2014-01-01

    We study a smooth cosmological solution of the 5D anisotropic standing wave braneworld model generated by gravity coupled to a phantom-like scalar field. In this model the brane emits anisotropic waves into the bulk with different amplitudes along different spatial dimensions. We found a natural mechanism which isotropizes the braneworld, rendering a 3-brane with de Sitter symmetry embedded in a 5D de Sitter space-time for a wide class of initial conditions. The resulting thick geometrical braneworld (a de Sitter 3-brane) possesses a series of remarkable features. By explicitly solving the bulk field equations we are able to give a physical interpretation of the anisotropic dissipation: as the anisotropic energy on the 3-brane rapidly leaks into the bulk, through the nontrivial Weyl tensor components, the bulk becomes less isotropic.

  12. Finite action, holographic conformal anomaly and quantum brane-worlds in d5 gauged supergravity

    CERN Document Server

    Nojiri, S; Odintsov, S D; Ogushi, S

    2002-01-01

    We report our recent results concerning d5 gauged supergravity (dilatonic gravity) considered on AdS background. The finite action on such background as well as d4 holographic conformal anomaly (via AdS/CFT correspondence) are found. In such formalism the bulk potential is kept to be arbitrary, dilaton dependent function. Holographic RG in such theory is briefly discussed. d5 AdS brane-world Universe induced by quantum effects of brane CFT is constructed. Such brane is spherical, hyperbolic or flat one. Hence, the possibility of quantum creation of inflationary brane-world Universe is shown.

  13. On cross-section computation in the brane-world models

    Science.gov (United States)

    Dmitry, Kirpichnikov

    2014-06-01

    We present Mathematica7 numerical simulation of the process pp → jet + E/Tin the framework of modified Randall-Sundrum brane-world model with one infinite and n compact extra dimension. We compare the energy missing signature with the standard model background pp → jet + vbar v, which was simulated at CompHep. We show that the models with numbers of compact extra dimensions greater than 4 can be probed at the protons center-of-mass energy equal 14 TeV. We also find that testing the brane-world models at 7 TeV on the LHC appears to hopeless.

  14. Gravitational Collapse and Black Hole Formation in a Braneworld

    CERN Document Server

    Wang, Daoyan

    2015-01-01

    In this thesis we present the first numerical study of gravitational collapse in braneworlds within the framework of the single brane model proposed by Randall and Sundrum (RSII). We directly show that the evolutions of sufficiently strong initial data configurations result in black holes (BHs) with finite extension into the bulk. The extension changes from sphere to pancake (or cigar, seen from a different perspective) as the size of BH increases. We find preliminary evidences that BHs of the same size generated from distinct initial data profiles are geometrically indistinguishable. As such, a no-hair theorem of BH (uniqueness of BH) is suggested to hold in the RSII spacetimes studied in this thesis---these spacetimes are axisymmetric without angular momentum and non-gravitational charges. In particular, the BHs we obtained as the results of the dynamical system, are consistent with the ones previously obtained from a static vacuum system by Figueras and Wiseman. We also obtained some results in closed form...

  15. New holographic dark energy model inspired by the DGP braneworld

    Science.gov (United States)

    Sheykhi, A.; Dehghani, M. H.; Ghaffari, S.

    2016-11-01

    The energy density of the holographic dark energy (HDE) is based on the area law of entropy, and thus any modification of the area law leads to a modified holographic energy density. Inspired by the entropy expression associated with the apparent horizon of a Friedmann-Robertson-Walker (FRW) universe in DGP braneworld, we propose a new model for the HDE in the framework of DGP brane cosmology. We investigate the cosmological consequences of this new model and calculate the equation of state (EoS) parameter by choosing the Hubble radius, L = H-1, as the system’s IR cutoff. Our study show that, due to the effects of the extra dimension (bulk), the identification of IR cutoff with Hubble radius, can reproduce the present acceleration of the universe expansion. This is in contrast to the ordinary HDE in standard cosmology which leads to the zero EoS parameter in the case of choosing the Hubble radius as system’s IR cutoff in the absence of interaction between dark matter (DM) and dark energy (DE).

  16. Five-dimensional Horava-like braneworld models

    CERN Document Server

    Bemfica, F S; Gomes, M; da Silva, J M Hoff

    2012-01-01

    In this work we study a Horava-like five-dimensional model in the context of braneworld theory. To begin with, the equations of motion of such model are obtained and, within the realm of warped geometry, we show that the model is consistent if and only if $\\lambda$ takes its relativistic value 1. Furthermore, since the first derivative of the warp factor is discontinuous over the branes, we show that the elimination of problematic terms involving the square of the warp factor second order derivatives are eliminated by imposing detailed balance condition in the bulk. Afterwards, the Israel's junction conditions are computed, allowing the attainment of an effective Lagrangian in the visible brane. In particular, for a (4+1)-dimensional Horava-like model defined in the bulk without cosmological constant, we show that the resultant effective Lagrangian in the brane corresponds to a (3+1)-dimensional Horava-like model with an emergent positive cosmological constant but without detailed balance condition. Now, rest...

  17. 5-dimensional braneworld with gravitating Nambu-Goto matching conditions

    CERN Document Server

    Kofinas, Georgios

    2013-01-01

    We continue the investigation of a recent proposal on alternative matching conditions for self-gravitating defects which generalize the standard matching conditions. The reasoning for this study is the need for consistency of the various codimension defects and the existence of a meaningful equation of motion at the probe limit, things that seem to lack from the standard approach. These matching conditions arise by varying the brane-bulk action with respect to the brane embedding fields (and not with respect to the bulk metric at the brane position) in a way that takes into account the gravitational back-reaction of the brane to the bulk. They always possess a Nambu-Goto probe limit and any codimension defect is seemingly consistent for any second order bulk gravity theory. Here, we consider in detail the case of a codimension-1 brane in five-dimensional Einstein gravity, derive the generic alternative junction conditions and find the Z_{2}-symmetric braneworld cosmology, as well as its bulk extension. Compar...

  18. Inflaton perturbations in brane-world cosmology with induced gravity

    CERN Document Server

    Koyama, K; Koyama, Kazuya; Mizuno, Shuntaro

    2006-01-01

    We study cosmological perturbations in the brane models with an induced Einstein-Hilbert term on a brane. We consider an inflaton confined to a de Sitter brane in a five-dimensional Minkowski spacetime. Inflaton fluctuations excite Kaluza-Klein modes of bulk metric perturbations with mass $m^2 = -2(2\\ell-1) (\\ell +1) H^2$ and $m^2 = -2\\ell(2\\ell+3) H^2$ where $\\ell$ is an integer. There are two branches ($\\pm$ branches) of solutions for the background spacetime. In the $+$ branch, which includes the self-accelerating universe, a resonance appears for a mode with $m^2 = 2 H^2$ due to a spin-0 perturbation with $m^2 = 2H^2$. The self-accelerating universe has a distinct feature because there is also a helicity-0 mode of spin-2 perturbations with $m^2 = 2H^2$. In the $-$ branch, which can be thought as the Randall-Sundrum type brane-world with the high energy quantum corrections, there is no resonance. At high energies, we analytically confirm that four-dimensional Einstein gravity is recovered, which is related...

  19. Localization of gravity on a thick braneworld without scalar fields

    CERN Document Server

    Herrera-Aguilar, Alfredo; Mora-Luna, Refugio Rigel

    2010-01-01

    In this work we present a simple thick braneworld model that is generated by an intriguing interplay between a 5D cosmological constant with a de Sitter metric induced in the 3-brane without the inclusion of scalar fields. We show that 4D gravity is localized on this brane, provide analytic expressions for the massive Kaluza-Klein (KK) fluctuation modes and also show that the spectrum of metric excitations displays a mass gap. We finally present the corrections to Newton's law due to these massive modes. This model has no naked singularities along the fifth dimension despite the existence of a mass gap in the graviton spectrum as it happens in thick branes with 4D Poincare symmetry, providing a simple model with very good features: the curvature is completely smooth along the fifth dimension, it localizes 4D gravity and the spectrum of gravity fluctuations presents a mass gap, a fact that rules out the existence of phenomenologically dangerous ultralight KK excitations in the model.

  20. On cross-section computation in the brane-world models

    CERN Document Server

    Kirpichnikov, D V

    2013-01-01

    We present Mathematica7 numerical simulation of the process $pp\\rightarrow\\mbox{jet}+E_{T}^{miss}$ in the framework of modified Randall-Sundrum brane-world model with one infinite and $n$ compact extra dimension. We compare the energy missing signature with the standard model background $pp\\rightarrow \\mbox{jet}+\

  1. Brane-world stars from minimal geometric deformation, and black holes

    Science.gov (United States)

    Casadio, Roberto; Ovalle, Jorge

    2014-02-01

    Using the effective four-dimensional Einstein field equations, we build analytical models of spherically symmetric stars in the brane-world, in which the external space-time contains both an ADM mass and a tidal charge. In order to determine the interior geometry, we apply the principle of minimal geometric deformation, which allows one to map general relativistic solutions to solutions of the effective four-dimensional brane-world equations. We further restrict our analysis to stars with a radius linearly related to the total general relativistic mass, and obtain a general relation between the latter, the brane-world ADM mass and the tidal charge. In these models, the value of the star's radius can then be taken to zero smoothly, thus obtaining brane-world black hole metrics with a tidal charge solely determined by the mass of the source and the brane tension. We find configurations which entail a partial screening of the gravitational mass, and general conclusions regarding the minimum mass for semiclassical black holes are also drawn.

  2. Can Effective Field Theory of inflation generate large tensor-to-scalar ratio within Randall–Sundrum single braneworld?

    Directory of Open Access Journals (Sweden)

    Sayantan Choudhury

    2015-05-01

    Full Text Available In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall–Sundrum (RS single braneworld scenario in a model independent fashion. By explicit computation I have shown that the effective field theory prescription of brane inflation within RS single brane setup is consistent with sub-Planckian excursion of the inflaton field, which will further generate large value of tensor-to-scalar ratio, provided the energy density for inflaton degrees of freedom is high enough compared to the brane tension in high energy regime. Finally, I have mentioned the stringent theoretical constraint on positive brane tension, cut-off of the quantum gravity scale and bulk cosmological constant to get sub-Planckian field excursion along with large tensor-to-scalar ratio as recently observed by BICEP2 or at least generates the tensor-to-scalar ratio consistent with the upper bound of Planck (2013 and 2015 data and Planck+BICEP2+Keck Array joint constraint.

  3. Can Effective Field Theory of inflation generate large tensor-to-scalar ratio within Randall–Sundrum single braneworld?

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Sayantan, E-mail: sayanphysicsisi@gmail.com

    2015-05-15

    In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall–Sundrum (RS) single braneworld scenario in a model independent fashion. By explicit computation I have shown that the effective field theory prescription of brane inflation within RS single brane setup is consistent with sub-Planckian excursion of the inflaton field, which will further generate large value of tensor-to-scalar ratio, provided the energy density for inflaton degrees of freedom is high enough compared to the brane tension in high energy regime. Finally, I have mentioned the stringent theoretical constraint on positive brane tension, cut-off of the quantum gravity scale and bulk cosmological constant to get sub-Planckian field excursion along with large tensor-to-scalar ratio as recently observed by BICEP2 or at least generates the tensor-to-scalar ratio consistent with the upper bound of Planck (2013 and 2015) data and Planck+BICEP2+Keck Array joint constraint.

  4. Regular Bulk Solutions in Brane-worlds with Inhomogeneous Dust and Generalized Dark Radiation

    CERN Document Server

    Herrera-Aguilar, A; da Rocha, Roldao

    2015-01-01

    From the dynamics of a brane-world with matter fields present in the bulk, the bulk metric and the black string solution near the brane are generalized, when both the dynamics of inhomogeneous dust/generalized dark radiation on the brane-world and inhomogeneous dark radiation in the bulk as well are considered -- as exact dynamical collapse solutions. Based on the analysis on the inhomogeneous static exterior of a collapsing sphere of homogeneous dark radiation on the brane, the associated black string warped horizon is studied, as well as the 5D bulk metric near the brane. Moreover, the black string and the bulk are shown to be more regular upon time evolution, for suitable values for the dark radiation parameter in the model, by analyzing the physical soft singularities.

  5. Late time accelerated scaling attractors in DGP (Dvali-Gabadadze-Porrati) braneworld

    CERN Document Server

    Dutta, Jibitesh; Syiemlieh, Erickson

    2016-01-01

    In the evolution of late universe, the main source of matter are Dark energy and Dark matter. They are indirectly detected only through their gravitational manifestations. So the possibility of interaction with each other without violating observational restrictions is not ruled out. With this motivation, we investigate the dynamics of DGP braneworld where source of dark energy is a scalar field and it interacts with matter source. Since observation favours phantom case more, we have also studied the dynamics of interacting phantom scalar field. In non interacting DGP braneworld there are no late time accelerated scaling attractors and hence cannot alleviate Coincidence problem. In this paper, we shall show that it is possible to get late time accelerated scaling solutions. The phase space is studied by taking two categories of potentials (Exponential and Non exponential functions). The stability of critical points are examined by taking two specific interactions. The first interaction gives late time acceler...

  6. Evolution of curvature perturbations in a brane-world inflation at high-energies

    CERN Document Server

    Hiramatsu, T; Hiramatsu, Takashi; Koyama, Kazuya

    2006-01-01

    We study the evolution of scalar curvature perturbations in a brane-world inflation model in a 5D Anti-de Sitter spacetime. The inflaton perturbations are confined to a 4D brane but they are coupled to the 5D bulk metric perturbations. We numerically solve full coupled equations for the inflaton perturbations and the 5D metric perturbations. At high energies, the inflaton perturbations are strongly coupled to the bulk metric perurbations even on subhorizon scales, leading to the suppression of the amplitude of the comoving curvature perturbation at a horizon crossing with a particular choice of initial conditions. This indicates the need to qunatise the coupled brane-bulk system in a consistent way in order to define an initial vacuum state and calculate the spectrum of the scalar perturbations in a brane-world inflation.

  7. Probing dark energy with braneworld cosmology in the light of recent cosmological data

    CERN Document Server

    Garcia-Aspeitia, Miguel A; Hernandez-Almada, Alberto; Motta, V

    2016-01-01

    In this paper, we consider a simple brane model with a generic dark energy component which could drive the accelerated expansion at late times of the Universe. We use the Supernovae type Ia, $H(z)$, baryon acoustic oscillations, and cosmic microwave background radiation measurements to constrain the brane tension, which is the main observable of the theory. From the study, we found an important tension between the different data sets and evidence of no gravity modifications by the existence of an extra dimension. Although this specific braneworld model is not compatible with the current cosmological observations and offers no new insights into the dark energy problem, it is not ruled out either. Our results show the need to further test of the braneworld model with appropriate correction terms.

  8. A critical analysis of thermodynamic properties of braneworld black holes in anti-de Sitter spacetime

    CERN Document Server

    Koley, Ratna; Pal, Supratik; SenGupta, Soumitra

    2009-01-01

    Thermodynamic properties of Schwarzschild-Anti de-Sitter (Sch-AdS) and Reissner-Nordstr\\"om-Anti de-Sitter (RN-AdS) blackholes in 3+1 dimensional spacetime are studied critically with special reference to the warped braneworld black holes with non-vanishing cosmological constant on the brane. Explicit dependence of the thermodynamic variables on the parameters of the braneworld model such as the induced three brane cosmological constant as well as the bulk cosmological constant have been determined. Hawking-Page phase transition has been discussed for both Sch-AdS and RN-AdS black holes. At the phase transition point it is shown that the parameters mass, charge and cosmological constant get correlated by an inequality relation which originates from the background warped geometry model.

  9. Universal spin-1/2 fermion field localization on a 5D braneworld

    CERN Document Server

    Barbosa-Cendejas, Nandinii; Mora-Luna, Refugio Rigel

    2015-01-01

    In this work we present a refined method for the localization of spin-$\\frac{1}{2}$ fermions on the 5D braneworld paradigm. We begin by proposing a more natural ansatz for the Yukawa coupling in the 5D bulk fermionic action, that guarantees the localization of the ground states for the 4D fermions with right or left chirality. Furthermore, we show that the fermion ground states localization allow us to show the absence of tachyonic modes in the left and right-chiral Kaluza-Klein mass spectrum. More precisely, we show that localization of gravity in the 5D braneworld implies the localization of the spin-$\\frac{1}{2}$ fermions.

  10. Regular Bulk Solutions in Brane-Worlds with Inhomogeneous Dust and Generalized Dark Radiation

    Directory of Open Access Journals (Sweden)

    A. Herrera-Aguilar

    2015-01-01

    Full Text Available From the dynamics of a brane-world with matter fields present in the bulk, the bulk metric and the black string solution near the brane are generalized, when both the dynamics of inhomogeneous dust/generalized dark radiation on the brane-world and inhomogeneous dark radiation in the bulk as well are considered as exact dynamical collapse solutions. Based on the analysis on the inhomogeneous static exterior of a collapsing sphere of homogeneous dark radiation on the brane, the associated black string warped horizon is studied, as well as the 5D bulk metric near the brane. Moreover, the black string and the bulk are shown to be more regular upon time evolution, for suitable values for the dark radiation parameter in the model, by analyzing the soft physical singularities.

  11. Triple Unification of Inflation, Dark matter and Dark energy in Chaotic Braneworld Inflation

    OpenAIRE

    Lin, Chia-Min(Department of Physics, Chuo University, Bunkyo-ku, Tokyo, 112 Japan)

    2009-01-01

    In this paper, we show that in the framework of chaotic braneworld inflation, after preheating, the remaining oscillating inflaton field can play the role of dark matter with the observed level. Augmented by a non-zero effective cosmological constant $\\Lambda_4$ on the brane, triple unification of inflation, dark matter and dark energy by a single field is realized. Our model perhaps is the simplest one in the market of theories to achieve triple unification.

  12. Semiclassical instability of the brane-world Randall-Sundrum bubbles

    CERN Document Server

    Ida, D; Ochiai, H; Ida, Daisuke; Shiromizu, Tetsuya; Ochiai, Hirotaka

    2002-01-01

    We discuss the semiclassical instability of the Randall-Sundrum brane-world model against a creation of a kind of Kaluza-Klein bubble. An example describing such a bubble space-time is constructed from the five-dimensional AdS-Schwarzschild metric. The induced geometry of the brane looks like the Einstein-Rosen bridge, which connects the positive and the negative tension branes. The bubble rapidly expands and there also form a trapped region around it.

  13. First law of thermodynamics and Friedmann-like equations in braneworld cosmology

    OpenAIRE

    Ge, Xian-Hui

    2007-01-01

    We derive the Friedmann-like equations in braneworld cosmology by imposing the first law of thermodynamics and Bekenstein's area-entropy formula on the apparent horizon of a Friedmann-Roberston-Walker universe in both Randall-Sundrum II gravity and Dvali-Gabadadze-Porrati gravity models. Israel's boundary condition plays an important role in our calculations in both cases, besides the first law of thermodynamics and Bekenstein's area-entropy formula. The results indicate that thermodynamics o...

  14. Classical Tests of General Relativity: Brane-World Sun from Minimal Geometric Deformation

    CERN Document Server

    Casadio, Roberto; da Rocha, Roldao

    2015-01-01

    We consider a solution of the effective four-dimensional brane-world equations, obtained from the General Relativistic Schwarzschild metric via the principle of Minimal Geometric Deformation, and investigate the corresponding signatures stemming from the possible existence of a warped extra dimension. In particular, we derive bounds on an extra-dimensional parameter, closely related with the fundamental gravitational length, from the experimental results of the classical tests of General Relativity in the Solar system.

  15. Classical tests of general relativity: Brane-world Sun from minimal geometric deformation

    Science.gov (United States)

    Casadio, R.; Ovalle, J.; da Rocha, Roldão

    2015-05-01

    We consider a solution of the effective four-dimensional brane-world equations, obtained from the general relativistic Schwarzschild metric via the principle of minimal geometric deformation, and investigate the corresponding signatures stemming from the possible existence of a warped extra-dimension. In particular, we derive bounds on an extra-dimensional parameter, closely related with the fundamental gravitational length, from the experimental results of the classical tests of general relativity in the Solar system.

  16. Hoop Conjecture and Cosmic Censorship in the Brane-World

    CERN Document Server

    Nakao, K; Mishima, T; Nakao, Ken-ichi; Nakamura, Kouji; Mishima, Takashi

    2003-01-01

    The initial data of gravity for a cylindrical matter distribution confined on the brane is studied in the framework of the single brane Randall-Sundrum scenario. In this scenario, 5-dimensional aspect of gravity appears in the short range gravitational interaction. We found that the sufficiently thin configuration of matter leads to the formation of the marginal surface even if the configuration is infinitely long. This means that the hoop conjecture proposed by Thorne does not hold in the Randall-Sundrum scenario; Even if a mass $M$ does not get compacted into a region whose circumference in every direction is ${\\cal C}\\le 4\\pi GM$, black holes with horizons can form in the Randall-Sundrum scenario.

  17. Discrete graviton spectrum from super-exponential cup potentials and their application to braneworld physics

    CERN Document Server

    Carrillo-Gonzalez, Mariana; Herrera-Aguilar, Alfredo; Hidalgo, Juan Carlos; Malagon-Morejon, Dagoberto

    2014-01-01

    Super-exponential warp factors have been proposed in the context of two-brane models to solve the gauge hierarchy problem of scales by using a compactification scale of the same order of the fundamental Planck scale, completely eliminating the hierarchy between the electroweak and the Planck scales. However, most of the so far studied families of braneworlds with super-exponential warp factors do not localize 4D gravity when one of the branes is sent to infinity. Recently a braneworld model generated by a canonical scalar field $\\phi$ minimally coupled to 5D gravity with a bulk cosmological constant was shown to localize 4D gravity and to be stable under linear tensorial and scalar perturbations. Here we present an explicit new solution for the latter braneworld configuration and study the dynamics of its tensorial perturbations: we find that they obey a Schr\\"odinger-like equation with a well potential which possesses exponentially increasing walls (we call it the {\\it cup potential}), yielding a {\\it novel ...

  18. Efficiency of the Keplerian accretion in the Braneworld Kerr--Newman Spacetimes and mining instability of some naked singularity spacetimes

    CERN Document Server

    Blaschke, Martin

    2016-01-01

    We show that the~braneworld rotating Kerr--Newman black hole and naked singularity spacetimes with both positive and negative braneworld tidal charge parameter can be separated into fourteen classes according to properties of circular geodesics governing the~Keplerian accretion. We determine efficiency of the~Keplerian accretion disks for all braneworld Kerr--Newman spacetimes. We demonstrate occurrence of an~infinitely deep gravitational potential in Kerr--Newman naked singularity spacetimes having the~braneworld dimensionless tidal charge $b \\in (1/4,1)$ and the~dimensionless spin $a \\in (2\\sqrt{b}-\\sqrt{b(4b-1)},2\\sqrt{b}+\\sqrt{b(4b-1)})$, implying unbound efficiency of the~Keplerian accretion and possibility to extract the~whole naked singularity mass. Therefore, we call them braneworld "mining-unstable" Kerr--Newman naked singularity spacetimes. Fundamental restriction on the~relevance of the~extraordinary but fully classical phenomenon of the~mining instability is given by validity of the~assumption of ...

  19. Scenario planning.

    Science.gov (United States)

    Enzmann, Dieter R; Beauchamp, Norman J; Norbash, Alexander

    2011-03-01

    In facing future developments in health care, scenario planning offers a complementary approach to traditional strategic planning. Whereas traditional strategic planning typically consists of predicting the future at a single point on a chosen time horizon and mapping the preferred plans to address such a future, scenario planning creates stories about multiple likely potential futures on a given time horizon and maps the preferred plans to address the multiple described potential futures. Each scenario is purposefully different and specifically not a consensus worst-case, average, or best-case forecast; nor is scenario planning a process in probabilistic prediction. Scenario planning focuses on high-impact, uncertain driving forces that in the authors' example affect the field of radiology. Uncertainty is the key concept as these forces are mapped onto axes of uncertainty, the poles of which have opposed effects on radiology. One chosen axis was "market focus," with poles of centralized health care (government control) vs a decentralized private market. Another axis was "radiology's business model," with one pole being a unified, single specialty vs a splintered, disaggregated subspecialty. The third axis was "technology and science," with one pole representing technology enabling to radiology vs technology threatening to radiology. Selected poles of these axes were then combined to create 3 scenarios. One scenario, termed "entrepreneurialism," consisted of a decentralized private market, a disaggregated business model, and threatening technology and science. A second scenario, termed "socialized medicine," had a centralized market focus, a unified specialty business model, and enabling technology and science. A third scenario, termed "freefall," had a centralized market focus, a disaggregated business model, and threatening technology and science. These scenarios provide a range of futures that ultimately allow the identification of defined "signposts" that can

  20. Scenario? Guilty!

    DEFF Research Database (Denmark)

    Kyng, Morten

    1992-01-01

    Robert Campbell categorizes the word "scenario" as a buzzword, identifies four major uses within HCI and suggests that we adopt new terms differentiating these four uses of the word. My first reaction to reading the article was definitely positive, but rereading it gave me enough second thoughts ...... to warrant a response. I should probably confess that I searched my latest paper for the word "scenario" and found eight occurrences, none of which fell in the categories described by Campbell....

  1. Compact stars in the braneworld: A new branch of stellar configurations with arbitrarily large mass

    Science.gov (United States)

    Lugones, Germán; Arbañil, José D. V.

    2017-03-01

    We study the properties of compact stars in the Randall-Sundrum type-II braneworld (BW) model. To this end, we solve the braneworld generalization of the stellar structure equations for a static fluid distribution with spherical symmetry considering that the spacetime outside the star is described by a Schwarzschild metric. First, the stellar structure equations are integrated employing the so-called causal limit equation of state (EOS), which is constructed using a well-established EOS at densities below a fiducial density, and the causal EOS P =ρ above it. It is a standard procedure in general relativistic stellar structure calculations to use such EOSs for obtaining a limit in the mass radius diagram, known as the causal limit, above which no stellar configurations are possible if the EOS fulfills the condition that the sound velocity is smaller than the speed of light. We find that the equilibrium solutions in the braneworld model can violate the general relativistic causal limit, and for sufficiently large mass they approach asymptotically to the Schwarzschild limit M =2 R . Then, we investigate the properties of hadronic and strange quark stars using two typical EOSs: a nonlinear relativistic mean-field model for hadronic matter and the Massachusetts Institute of Technology (MIT) bag model for quark matter. For masses below ˜1.5 M⊙- 2 M⊙ , the mass versus radius curves show the typical behavior found within the frame of general relativity. However, we also find a new branch of stellar configurations that can violate the general relativistic causal limit and that, in principle, may have an arbitrarily large mass. The stars belonging to this new branch are supported against collapse by the nonlocal effects of the bulk on the brane. We also show that these stars are always stable under small radial perturbations. These results support the idea that traces of extra dimensions might be found in astrophysics, specifically through the analysis of masses and

  2. Localization of Matter Fields in the 5D Standing Wave Braneworld

    CERN Document Server

    Gogberashvili, Merab

    2012-01-01

    We investigate the localization problem of matter fields within the 5D standing wave braneworld. In this model the brane emits anisotropic waves into the bulk with different amplitudes along different spatial dimensions. We show that in the case of increasing warp factor there exist the pure gravitational localization of all kinds of quantum and classical particles on the brane. For classical particles the anisotropy of the background metric is hidden, brane fields exhibit standard Lorentz symmetry in spite of anisotropic nature of the primordial 5D metric.

  3. Anisotropic Inflation in a 5D Standing Wave Braneworld and Dimensional Reduction

    CERN Document Server

    Gogberashvili, Merab; Malagon-Morejon, Dagoberto; Mora-Luna, Refugio Rigel

    2012-01-01

    We investigate a cosmological solution within the framework of a 5D standing wave braneworld model generated by gravity coupled to a massless scalar phantom-like field. By obtaining a full exact solution of the model we found a novel dynamical mechanism in which the anisotropic nature of the primordial metric gives rise to i) inflation along certain spatial dimensions, and ii) deflation and a shrinking reduction of the number of spatial dimensions along other directions. This dynamical mechanism can be relevant for dimensional reduction in string and other higher dimensional theories in the attempt of getting a 4D isotropic expanding space-time.

  4. Generalized virial theorem in warped DGP brane-world

    CERN Document Server

    Heydari-Fard, Malihe

    2012-01-01

    We generalize the virial theorem to the warped DGP brane world scenario and consider its implications on the virail mass. In this theory the four dimensional scalar curvature term is included in the bulk action and the resulting four dimensional effective Einstein equation is augmented with extra terms which can be interpreted as geometrical mass, contributing to the gravitational energy. Estimating the geometrical mass using the observational data, we show that these geometric terms may account for the virial mass discrepancy in clusters of galaxies. Finally, we obtain the radial velocity dispersion of galaxy clusters and show that it is compatible with the radial velocity dispersion profle of such clusters.

  5. Solution of a Braneworld Big Crunch/Big Bang Cosmology

    CERN Document Server

    McFadden, P; Turok, N G; Fadden, Paul Mc; Steinhardt, Paul J.; Turok, Neil

    2005-01-01

    We solve for the cosmological perturbations in a five-dimensional background consisting of two separating or colliding boundary branes, as an expansion in the collision speed V divided by the speed of light c. Our solution permits a detailed check of the validity of four-dimensional effective theory in the vicinity of the event corresponding to the big crunch/big bang singularity. We show that the four-dimensional description fails at the first nontrivial order in (V/c)^2. At this order, there is nontrivial mixing of the two relevant four-dimensional perturbation modes (the growing and decaying modes) as the boundary branes move from the narrowly-separated limit described by Kaluza-Klein theory to the well-separated limit where gravity is confined to the positive-tension brane. We comment on the cosmological significance of the result and compute other quantities of interest in five-dimensional cosmological scenarios.

  6. (Non)-singular brane-world cosmology induced by quantum effects in d5 dilatonic gravity

    CERN Document Server

    Nojiri, S; Odintsov, S D; Nojiri, Shin'ichi; Obregon, Octavio; Odintsov, Sergei D.

    2000-01-01

    5d dilatonic gravity (bosonic sector of gauged supergravity) with non-trivial bulk potential and with surface terms (boundary cosmological constant and trace anomaly induced effective action for brane quantum matter) is considered. For constant bulk potential and maximally SUSY Yang-Mills theory (CFT living on the brane) the inflationary brane-world is constructed. There, bulk is singular asymptotically AdS space with non-constant dilaton and dilatonic de Sitter or hyperbolic brane is induced by quantum matter effects. On the same time, dilaton on the brane is determined dynamically. This all is natural realization of warped compactification in AdS/CFT correspondence. For fine-tuned toy example of non-constant bulk potential we found the non-singular dilatonic brane-world where bulk again represents asymptotically AdS space and de Sitter brane (inflationary phase of observable Universe) is induced exclusively by quantum effects. The radius of brane and dilaton are determined dynamically. The analytically solv...

  7. On the Localisation of 4-Dimensional Brane-World Black Holes

    CERN Document Server

    Kanti, P; Zuleta, K

    2013-01-01

    In the context of brane-world models, we pursue the question of the existence of 5-dimensional solutions describing regular black holes localised close to the brane. Employing a perturbed Vaidya-type line-element embedded in a warped fifth dimension, we attempt to localise the extended black-string singularity, and to restore the regularity of the AdS spacetime at a finite distance from the brane by introducing an appropriate bulk energy-momentum tensor. As a source for this bulk matter, we are considering a variety of non-ordinary field-theory models of scalar fields either minimally-coupled to gravity, but including non-canonical kinetic terms, mixing terms, derivative interactions and ghosts, or non-minimally-coupled to gravity through a general coupling to the Ricci scalar. In all models considered, even in the ones characterised by a high-degree of flexibility, a negative result was reached. Our analysis demonstrates how difficult the analytic construction of a localised brane-world black hole may be in ...

  8. Evolution of gravitational waves from inflationary brane-world numerical study of high-energy effects

    CERN Document Server

    Hiramatsu, T; Taruya, A; Hiramatsu, Takashi; Koyama, Kazuya; Taruya, Atsushi

    2004-01-01

    We study the evolution of gravitational waves(GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter spacetime. Contrary to the standard four-dimensional results, the GWs at the high-energy regime in brane-world model suffer from the effects of the non-standard cosmological expansion and the excitation of the Kaluza-Klein modes(KK-modes), which can affect the amplitude of stochastic gravitational wave background significantly. To investigate these two high-energy effects quantitatively, we numerically solve the wave equation of the GWs in the radiation dominated epoch at relatively low-energy scales. We show that the resultant GWs is suppressed by the excitation of the KK modes. The created KK modes are rather soft and escape away from the brane to the bulk gravitational field. The results are also compared to the semi-analytic prediction from the low-energy approximation and the evolved amplitude of GWs on the brane reasonably matches the numerical simulations.

  9. Black Strings from Minimal Geometric Deformation in a Variable Tension Brane-World

    CERN Document Server

    Casadio, Roberto; da Rocha, Roldao

    2013-01-01

    We study brane-world models with variable brane tension and compute corrections to the horizon of a black string along the extra dimension. The four-dimensional geometry of the black string on the brane is obtained by means of the minimal geometric deformation approach, and the bulk corrections are then encoded in additional terms involving the covariant derivatives of the variable brane tension. Our investigation shows that the variable brane tension strongly affects the shape and evolution of the black string horizon along the extra dimension, at least in a near-brane expansion. In particular, we apply our general analysis to a model motivated by the E\\"otv\\"os branes, where the variable brane tension is related to the Friedmann-Robertson-Walker brane-world cosmology. We show that for some stages in the evolution of the universe, the black string warped horizon collapses to a point and the black string has correspondingly finite extent along the extra dimension. Furthermore, we show that in the minimal geom...

  10. Black strings from minimal geometric deformation in a variable tension brane-world

    Science.gov (United States)

    Casadio, R.; Ovalle, J.; da Rocha, Roldão

    2014-02-01

    We study brane-world models with variable brane tension and compute corrections to the horizon of a black string along the extra dimension. The four-dimensional geometry of the black string on the brane is obtained by means of the minimal geometric deformation approach, and the bulk corrections are then encoded in additional terms involving the covariant derivatives of the variable brane tension. Our investigation shows that the variable brane tension strongly affects the shape and evolution of the black string horizon along the extra dimension, at least in a near-brane expansion. In particular, we apply our general analysis to a model motivated by the Eötvös branes, where the variable brane tension is related to the Friedmann-Robertson-Walker brane-world cosmology. We show that for some stages in the evolution of the universe, the black string warped horizon collapses to a point and the black string has correspondingly finite extent along the extra dimension. Furthermore, we show that in the minimal geometric deformation of a black hole on the variable tension brane, the black string has a throat along the extra dimension, whose area tends to zero as time goes to infinity.

  11. Scenario analysis

    NARCIS (Netherlands)

    Li, L.; Braat, L.C.; Lei, G.; Arets, E.J.M.M.; Liu, J.; Jiang, L.; Fan, Z.; Liu, W.; He, H.; Sun, X.

    2014-01-01

    This chapter presents the results of the scenario analysis of China’s ecosystems focusing on forest, grassland, and wetland ecosystems. The analysis was undertaken using Conversion of Land Use Change and its Effects (CLUE) modeling and an ecosystem service matrix (as explained below) complemented by

  12. Crossing the phantom divide, the generalized Chaplygin gas and RS braneworlds

    CERN Document Server

    García-Compéan, H; Obregón, O; Ramírez, C

    2007-01-01

    We study the unified generalized Chaplygin gas model in the framework of Randall-Sundrum braneworld, assuming a self-interacting dark energy-matter fluid. We find that a particular splitting of the densities of dark energy and matter (dark and baryonic), allows the possibility that the equation of state for dark energy crosses the phantom divide at the recent epoch. Moreover these densities decay during all the evolution of the Universe, avoiding a Big Rip. We find also a scaling solution such that the ratio of these densities tends asymptotically in the future to a value slightly different than the present one. This could provide an insight towards the solution to the coincidence problem.

  13. Generalized axion-photon couplings and dual descriptions on brane-worlds

    CERN Document Server

    Tahim, M O

    2005-01-01

    In this work we obtain topological and dual theories on brane-worlds in several dimensions. Our brane is a solitonic-like hypersurface embedded in a space-time with a specific dimensionality and it appears due to the breaking of a Peccei-Quinn-like symmetry. In the first part of this work, the obtained topological theories are related to a generalization of the axion-foton anomalous interaction in D=4 (in the Abelian case) and to the Wess-Zumino term (in the non-Abelian case). In the second part, we construct dual models on the brane through a mechanism of explicit Lorentz symmetry breaking. The gauge symmetries of such models are discussed within the Stuckelberg formalism.

  14. Gravitational waves from braneworld neutrino oscillations at supernova core-collapse

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera Cuesta, Herman J. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Lab. de Cosmologia e Fisica Experimental de Altas Energias]. E-mail: hermanjc@cbpfsul.cat.cbpf.br

    2003-07-01

    In braneworld-like solutions of the hierarchy problem gravitons and right-handed (sterile) neutrinos are in principle the unique non-standard model fields allowed to propagate into the bulk, thus their coupling is naturally expected. Since active-to-sterile neutrino oscillations can take place during the core bounce of a supernova collapse, then gravitational waves must be produced over the oscillation length through anisotropic neutrino flow. Because the oscillation feeds mass-energy up into (or takes it out of) the target species, the large mass-squared difference between species makes a huge amount of energy to be given off as gravity waves, which is larger than from neutrino convection and cooling, or quadrupole moments of neutron star matter. The space-time strain from these bursts would turn them the more sure supernova gravitational-wave signal detectable by inferometers, for distances out to the VIRGO cluster of galaxies. (author)

  15. Non-linear interactions in a cosmological background in the DGP braneworld

    CERN Document Server

    Koyama, K; Koyama, Kazuya; Silva, Fabio P

    2007-01-01

    We study quasi-static perturbations in a cosmological background in the Dvali-Gabadadze-Porrati (DGP) braneworld model. We identify the Vainshtein radius at which the non-linear interactions of the brane bending mode become important in a cosmological background. The Vainshtein radius in the early universe is much smaller than the one in the Minkowski background, but in a self-accelerating universe it is the same as the Minkowski background. Our result shows that the perturbative approach is applicable beyond the Vainshtein radius for weak gravity by taking into account the second order effects of the brane bending mode. The linearised cosmological perturbations are shown to be smoothly matched to the solutions inside the Vainshtein radius. We emphasize the importance of imposing a regularity condition in the bulk by solving the 5D perturbations and we highlight the problem of ad hoc assumptions on the bulk gravity that lead to different conclusions.

  16. Brane-world and loop cosmology from a gravity–matter coupling perspective

    Energy Technology Data Exchange (ETDEWEB)

    Olmo, Gonzalo J., E-mail: gonzalo.olmo@csic.es [Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia – CSIC, Universidad de Valencia, Burjassot-46100, Valencia (Spain); Departamento de Física, Universidade Federal da Paraíba, 58051-900 João Pessoa, Paraíba (Brazil); Rubiera-Garcia, D., E-mail: drubiera@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-900 João Pessoa, Paraíba (Brazil)

    2015-01-05

    We show that the effective brane-world and the loop quantum cosmology background expansion histories can be reproduced from a modified gravity perspective in terms of an f(R) gravity action plus a g(R) term non-minimally coupled with the matter Lagrangian. The reconstruction algorithm that we provide depends on a free function of the matter density that must be specified in each case and allows to obtain analytical solutions always. In the simplest cases, the function f(R) is quadratic in the Ricci scalar, R, whereas g(R) is linear. Our approach is compared with recent results in the literature. We show that working in the Palatini formalism there is no need to impose any constraint that keeps the equations second-order, which is a key requirement for the successful implementation of the reconstruction algorithm.

  17. Observational constrains on the DGP brane-world model with a Gauss-Bonnet term in the bulk

    Energy Technology Data Exchange (ETDEWEB)

    He Jianhua [Department of Physics, Fudan University, 200433 Shanghai (China); Wang Bin [Department of Physics, Fudan University, 200433 Shanghai (China)], E-mail: wangb@fudan.edu.cn; Papantonopoulos, Eleftherios [Department of Physics, National Technical University of Athens, GR 157 73, Athens (Greece)], E-mail: lpapa@central.ntua.gr

    2007-10-18

    Using the data coming from the new 182 Gold type Ia supernova samples, the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey and the H(z) data, we have performed a statistical joint analysis of the DGP brane-world model with a high curvature Gauss-Bonnet term in the bulk. Consistent parameters estimations show that the Gauss-Bonnet-induced gravity model is a viable candidate to explain the observed acceleration of our universe.

  18. Localization and quasilocalization of a spin-1 /2 fermion field on a two-field thick braneworld

    Science.gov (United States)

    Guo, Heng; Xie, Qun-Ying; Fu, Chun-E.

    2015-11-01

    Localization of a spin-1 /2 fermion on the braneworld is an important and interesting problem. It is well known that a five-dimensional free massless fermion Ψ minimally coupled to gravity cannot be localized on the Randall-Sundrum braneworld. In order to trap such a fermion, the coupling between the fermion and bulk scalar fields should be introduced. In this paper, localization and quasilocalization of a bulk fermion on the thick braneworld generated by two scalar fields (a kink scalar ϕ and a dilaton scalar π ) are investigated. Two types of couplings between the fermion and two scalars are considered. One coupling is the usual Yukawa coupling -η Ψ ¯ϕ Ψ between the fermion and kink scalar, another one is λ Ψ ¯ΓM∂Mπ γ5Ψ between the fermion and dilaton scalar. The left-chiral fermion zero mode can be localized on the brane, and both the left- and right-chiral fermion massive Kaluza-Klein modes may be localized or quasilocalized. Hence the four-dimensional massless left-chiral fermion and massive Dirac fermions, whose lifetime is infinite or finite, can be obtained on the brane.

  19. New observational limits on dark radiation in brane-world cosmology

    CERN Document Server

    Sasankan, Nishanth; Mathews, Grant J; Kusakabe, Motohiko

    2016-01-01

    A dark radiation term arises as a correction to the energy momentum tensor in the simplest five-dimensional RS-II brane-world cosmology. In this paper we revisit the constraints on dark radiation based upon the newest results for light-element nuclear reaction rates, observed light-element abundances and the power spectrum of the Cosmic Microwave Background (CMB). Adding the effect of dark radiation during big bang nucleosynthesis alters the Friedmann expansion rate causing the nuclear reactions to freeze out at a different temperature. This changes the final light element abundances at the end of BBN. Its influence on the CMB is to change the effective expansion rate at the surface of last scattering. We find that the BBN constraint reduces the the allowed range for dark radiation to between -12.1% and +6.2% of the photon background. Combining this result with fits to the CMB power spectrum constraint, the range decreases to -6.0% to +6.2%. Thus, we find, that the ratio of dark radiation to the background to...

  20. Localization of gauge fields in a tachyonic de Sitter thick braneworld

    Energy Technology Data Exchange (ETDEWEB)

    Herrera-Aguilar, Alfredo [Universidad Autonoma de Chiapas, Ciudad Universitaria, Mesoamerican Centre for Theoretical Physics, Kilometro 4, Carretera Emiliano Zapata, Colonia Real del Bosque (Teran), Tuxtla Gutierrez, Chiapas (Mexico); Universidad Autonoma Metropolitana Iztapalapa, Departamento de Fisica, Mexico, D.F. (Mexico); Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Fisica y Matematicas, Morelia, Michoacan (Mexico); Rojas, Alma D. [Universidad Autonoma de Chiapas, Ciudad Universitaria, Mesoamerican Centre for Theoretical Physics, Kilometro 4, Carretera Emiliano Zapata, Colonia Real del Bosque (Teran), Tuxtla Gutierrez, Chiapas (Mexico); AHEP Group, Instituto de Fisica Corpuscular C.S.I.C./Universitat de Valencia, Paterna (Valencia) (Spain); Santos, Eli [Universidad Autonoma de Chiapas, Ciudad Universitaria, Mesoamerican Centre for Theoretical Physics, Kilometro 4, Carretera Emiliano Zapata, Colonia Real del Bosque (Teran), Tuxtla Gutierrez, Chiapas (Mexico)

    2014-04-15

    In this work we show that universal gauge vector fields can be localized on the recently proposed 5D thick tachyonic braneworld which involves a de Sitter cosmological background induced on the 3-brane. Namely, by performing a suitable decomposition of the vector field, the resulting 4D effective action corresponds to a massive gauge field, while the profile along the extra dimension obeys a Schroedinger-like equation with a Poeschl-Teller potential. It turns out that the massless zero mode of the gauge field is bound to the expanding 3-brane and allows us to recover the standard 4D electromagnetic phenomena of our world. Moreover, this zero mode is separated from the continuum of Kaluza-Klein (KK) modes by a mass gap determined by the scale of the expansion parameter. We also were able to analytically solve the corresponding Schroedinger-like equation for arbitrary mass, showing that KK massive modes asymptotically behave like plane waves, as expected. (orig.)

  1. Instability of de Sitter brane and horizon entropy in 6D braneworld

    CERN Document Server

    Kinoshita, Shunichiro; Mukohyama, Shinji

    2007-01-01

    We investigate thermodynamic and dynamical stability of a family of six-dimensional braneworld solutions with de Sitter branes. First, we investigate thermodynamic stability in terms of de Sitter entropy. We see that the family of solutions is divided into two distinct branches: the high-entropy branch and the low-entropy branch. By analogy with ordinary thermodynamics, it is expected that the high-entropy branch be stable and the low-entropy branch be unstable. Next, we investigate dynamical stability by analyzing linear perturbations around the solutions. Perturbations are decomposed into scalar-, vector- and tensor-sectors according to the representation of the 4D de Sitter symmetry, and each sector is analyzed separately. It is found that when the Hubble expansion rates on the branes are too large, there appears a tachyonic mode in the scalar sector and the background solution becomes dynamically unstable. We analytically show that the onset of the thermodynamic instability and that of the dynamical insta...

  2. The Gospel according to DeWitt revisited: quantum effective action in braneworld models

    CERN Document Server

    Barvinsky, A O

    2005-01-01

    We construct quantum effective action in spacetimes with branes (boundaries) and establish its relation to the "cosmological wave function" of the bulk -- the solution of the corresponding Wheeler-DeWitt equation which can be considered as a means of the holographic description of braneworld models. We show that for a special type of the bulk-brane gauge fixing procedure the one-loop part of the action decouples into the additive sum of brane-to-brane and bulk-to-bulk effective actions, and this decomposition proliferates in a special way in higher orders of the Feynman diagrammatic expansion. This property is based on a special duality relation between the Dirichlet and Neumann boundary value problems when applied to the functional determinants of wave operators and the field-theoretic version of the well-known semiclassical Van Vleck-Morette determinant. It facilitates the gauge-independent way of treating the strong-coupling and VDVZ problems in brane induced gravity models. Importance of this technique in...

  3. Coulomb's law corrections and fermion field localization in a tachyonic de Sitter thick braneworld

    CERN Document Server

    Cartas-Fuentevilla, R; Germán, Gabriel; Herrera-Aguilar, Alfredo; Mora-Luna, Refugio Rigel

    2014-01-01

    In this work, following recent studies which show that it is possible to localize gravity as well as scalar and gauge vector fields in a tachyonic de Sitter thick braneworld, we investigate the localization of fermion fields in this model. In order to achieve this aim we consider the Yukawa interaction term between the fermions and the tachyonic condensate scalar field MF(T)barPsiPsi in the action and analyze four different cases corresponding to distinct tachyonic functions F(T(w)). The only condition that this function must satisfy in order to yield 4D chiral fermions upon dimensional reduction is to be odd in the extra dimension w. These functions lead to a different structure of the respective fermionic mass spectrum. In particular, localization of the massless left-chiral fermion zero mode is possible for three of these cases. We further analyze the phenomenology of the Yukawa interaction among fermion fields and gauge bosons localized on the brane and obtain the crucial and necessary information to comp...

  4. Gravity localization in non-minimally coupled scalar thick braneworlds with a Gauss-Bonnet term

    Energy Technology Data Exchange (ETDEWEB)

    Malagon-Morejon, D; Quiros, I [Division de Ciencias e IngenierIa de la Universidad de Guanajuato, A.P. 150, 37150, Leon, Guanajuato (Mexico); Herrera-Aguilar, A, E-mail: malagon@ifm.umich.mx, E-mail: herrera@ifm.umich.mx, E-mail: iquiros@fisica.ugto.mx

    2011-04-01

    We consider a warped five-dimensional thick braneworld with a four-dimensional Poincare invariant space-time in the framework of scalar matter non-minimally coupled to gravity plus a Gauss-Bonnet term in the bulk. Scalar field and higher curvature corrections to the background equations as well as the perturbed equations are shown. A relationship between 4-dimensional and 5-dimensional Planck masses is studied in general terms. By imposing finiteness of the 4-dimensional Planck mass and regularity of the geometry, the localization properties of the tensor modes of the first order perturbed geometry are analized for an important class of solutions motivated by models with scalar fields which are minimally coupled to gravity. In order to study the gravity localization properties for this model, the normalizability condition for the lowest level of the tensor fluctuations is analized. We see that for the class of solutions examined, gravity in 4 dimensions is recovered if the curvature invariants are regular and Planck masses are finite.

  5. Exposure scenarios for workers

    NARCIS (Netherlands)

    Marquart, H.; Northage, C.; Money, C.

    2007-01-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate con

  6. Participatory Scenario Planning

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The paper describes the paradigm, framework and a guideline how to use scenario methods in a workshop......The paper describes the paradigm, framework and a guideline how to use scenario methods in a workshop...

  7. Exposure scenarios for workers

    NARCIS (Netherlands)

    Marquart, H.; Northage, C.; Money, C.

    2007-01-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate

  8. Large lepton mixing angles from a 4+1-dimensional SU(5) x A(4) domain-wall braneworld model

    CERN Document Server

    Callen, Benjamin D

    2012-01-01

    We propose an extension of the 4+1D SU(5) domain-wall braneworld of Davies, George and Volkas which includes the addition of a discrete A(4) flavor symmetry. We show that lepton mixing and light Majorana neutrino masses can be generated from the additional A(4) physics while at the same time sufficient parameter freedom can be maintained in the charged fermion sector to produce charged fermion masses and quark mixing naturally from the split fermion mechanism. Importantly, we show that the vacuum realignment problem typical of discrete flavor symmetry models of quark and lepton mixing can be solved by separating the appropriate flavons in the extra dimension, leading to exponentially sensitive suppression of the operators responsible for vacuum realignment.

  9. Study of field fluctuations and their localization in a thick braneworld generated by gravity non-minimally coupled to a scalar field with a Gauss-Bonnet term

    CERN Document Server

    Germán, Gabriel; Malagón--Morejón, Dagoberto; Quiros, Israel; da Rocha, Roldão

    2014-01-01

    We consider warped five-dimensional smooth braneworlds with 4D dimensional Poincar\\'e invariance originated from bulk scalar matter non-minimally coupled to gravity with an additional a Gauss-Bonnet term. We present exact solutions for the full braneworld configuration in contrast to previous results where only approximate solutions were constructed due to the highly non-linear character of the relevant differential equations. These{}{solutions allow us to} study the necessary conditions for the finiteness of the 4D Planck mass and its relation to a more rigorous analysis of 4D gravity localization. We also analyze the localization properties of scalar, vector and tensor fluctuation modes for the constructed field configurations. We show that for the considered backgrounds, only the massless tensor mode, i.e. the 4D graviton, is localized on the brane, while the vector and scalar modes are not confined to the brane.

  10. Review of Climate Scenarios

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Concept and application requirements of climate scenarios were introduced briefly,meanwhile,progresses on theoretical and applied aspects of climate scenarios creation techniques were discussed systematically.Two methods on predicted regional climate changing scenarios,elevating the spatial resolution output and downscaling method,could retrieve the insufficiencies respectively.And the statistical-dynamical downscaling method will be an important developing trend in the developing of downscaling techniques.

  11. Food scenarios 2025

    DEFF Research Database (Denmark)

    Sundbo, Jon

    2016-01-01

    This article presents the results of a future study of the food sector. Two scenarios have been developed using a combination of: 1) a summary of the relevant scientific knowledge, 2) systematic scenario writing, 3) an expert-based Delphi technique, and 4) an expert seminar assessment. The two...... scenarios present possible futures at global, national (Denmark) and regional (Zealand, Denmark) levels. The main scenario is called ‘Food for ordinary days and celebrations’ (a combination of ‘High-technological food production − The functional society’ and ‘High-gastronomic food − The experience society...

  12. Scenarios for nature development

    NARCIS (Netherlands)

    Harms, W.B.

    1995-01-01

    A procedure in backcasting scenarios is presented. Two case-studies differing in scale illustrate the differences in ecological contribution to plan design and to plan evaluation. Scenarios for nature development are presented for both case-studies, based on ecological objectives and spatial strateg

  13. Nuclear Security Futures Scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Elizabeth James Kistin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warren, Drake Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hayden, Nancy Kay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Passell, Howard D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Malczynski, Leonard A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-01-01

    This report provides an overview of the scenarios used in strategic futures workshops conducted at Sandia on September 21 and 29, 2016. The workshops, designed and facilitated by analysts in Center 100, used scenarios to enable thought leaders to think collectively about the changing aspects of global nuclear security and the potential implications for the US Government and Sandia National Laboratories.

  14. Learning Through Scenario Planning

    DEFF Research Database (Denmark)

    Balarezo, Jose

    This project investigates the uses and effects of scenario planning in companies operating in highly uncertain and dynamic environments. Whereas previous research on scenario planning has fallen short of providing sufficient evidence of its mechanisms and effects on individual or organizational...... level variables, this research corrects this void by investigating the dynamics of organizational learning through the lenses of a corporate scenario planning process. This enhances our scientific understanding of the role that scenario planning might play in the context of organizational learning...... and counterintuitive ways in which an organization uses scenario planning in balancing the tension between exploration and exploitation. Moreover, this research proposes two novel mechanisms designed to enhance learning flows. At the core of this dissertation are four papers which in combination solidify our...

  15. Integrative Scenario Development

    Directory of Open Access Journals (Sweden)

    Joerg A. Priess

    2014-03-01

    Full Text Available Scenarios are employed to address a large number of future environmental and socioeconomic challenges. We present a conceptual framework for the development of scenarios to integrate the objectives of different stakeholder groups. Based on the framework, land-use scenarios were developed to provide a common base for further research. At the same time, these scenarios assisted regional stakeholders to bring forward their concerns and arrive at a shared understanding of challenges between scientific and regional stakeholders, which allowed them to eventually support regional decision making. The focus on the integration of views and knowledge domains of different stakeholder groups, such as scientists and practitioners, required rigorous and repeated measures of quality control. The application of the integrative concept provided products for both stakeholder groups, and the process of scenario development facilitated cooperation and learning within both the scientist and practitioner groups as well as between the two groups.

  16. Exposure scenarios for workers.

    Science.gov (United States)

    Marquart, Hans; Northage, Christine; Money, Chris

    2007-12-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate considerations of both human health and the environment. Specific aspects are relevant for worker exposure. Gathering information on the uses of the chemical is an important step in developing an Exposure Scenario. In-house information at manufacturers is an important source. Downstream users can contribute information through direct contact or through their associations. Relatively simple approaches (Tier 1 tools, such as the ECETOC Targeted Risk Assessment and the model EASE) can be used to develop broad Exposure Scenarios that cover many use situations. These approaches rely on the categorisation of just a few determinants, including only a small number of risk management measures. Such approaches have a limited discriminatory power and are rather conservative. When the hazard of the substance or the complexity of the exposure situation require a more in-depth approach, further development of the Exposure Scenarios with Tier 2 approaches is needed. Measured data sets of worker exposure are very valuable in a Tier 2 approach. Some downstream user associations have attempted to build Exposure Scenarios based on measured data sets. Generic Tier 2 tools for developing Exposure Scenarios do not exist yet. To enable efficient development of the worker exposure part of Exposure Scenarios a further development of Tier 1 and Tier 2 tools is needed. Special attention should be given to user friendliness and to the validity (boundaries) of the approaches. The development of standard worker exposure descriptions or full Exposure Scenarios by downstream user branches in cooperation with manufacturers and importers is recommended.

  17. Crossing the cosmological constant line in a dilatonic brane-world model with and without curvature corrections

    CERN Document Server

    Bouhmadi-Lopez, Mariam

    2008-01-01

    We construct a new brane-world model composed of a bulk -with a dilatonic field-, plus a brane -with brane tension coupled to the dilaton-, cold dark matter and an induced gravity term. It is possible to show that depending on the nature of the coupling between the brane tension and the dilaton this model can describe the late-time acceleration of the brane expansion (for the normal branch) as it moves within the bulk. The acceleration is produced together with a mimicry of the crossing of the cosmological constant line (w=-1) on the brane, although this crossing of the phantom divide is obtained without invoking any phantom matter neither on the brane nor in the bulk. The role of dark energy is played by the brane tension, which reaches a maximum positive value along the cosmological expansion of the brane. It is precisely at that maximum that the crossing of the phantom divide takes place. We also show that these results remain valid when the induced gravity term on the brane is switched off.

  18. Crossing the cosmological constant line in a dilatonic brane-world model with and without curvature corrections

    Energy Technology Data Exchange (ETDEWEB)

    Bouhmadi-Lopez, Mariam [Centro Multidisciplinar de Astrofisica-CENTRA, Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Ferrera, Antonio, E-mail: mariam.bouhmadi@fisica.ist.utl.pt, E-mail: a.ferrera.pardo@gmail.com [Centro de Fisica ' Miguel A Catalan' , Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)

    2008-10-15

    We construct a new brane-world model composed of a bulk with a dilatonic field, plus a brane with brane tension coupled to the dilaton, cold dark matter and an induced gravity term. It is possible to show that, depending on the nature of the coupling between the brane tension and the dilaton, this model can describe the late time acceleration of the brane expansion (for the normal branch) as it moves within the bulk. The acceleration is produced together with a mimicry of the crossing of the cosmological constant line (w = -1) on the brane, although this crossing of the phantom divide is obtained without invoking any phantom matter either on the brane or in the bulk. The role of dark energy is played by the brane tension, which reaches a maximum positive value along the cosmological expansion of the brane. It is precisely at that maximum that the crossing of the phantom divide takes place. We also show that these results remain valid when the induced gravity term on the brane is switched off.

  19. Interrelated aspects of thick braneworlds: 4D gravity localization, smoothness of geometry and mass gap in the graviton spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Herrera-Aguilar, A; Malagon-Morejon, D; Mora-Luna, R R; Nucamendi, U, E-mail: herrera@ifm.umich.m, E-mail: malagon@ifm.umich.m, E-mail: topc@ifm.umich.m, E-mail: ulises@ifm.umich.m [Instituto de Fisica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo. Edificio C-3, Ciudad Universitaria, C.P. 58040, Morelia, Michoacan (Mexico)

    2010-04-01

    We review some interrelated aspects of thick braneworlds which arise within the framework of 5D gravity coupled to a bulk scalar field. When studying localization of 4D gravity in this smooth version of the thin brane Randall-Sundrum model, a kind of dichotomy emerges: if one requires the geometry of the system to be completely smooth, then there is no mass gap in the spectrum of metric fluctuations since it contains just a single massless bound state, interpreted as a 4D graviton, and a tower of massive states starting from zero mass; on the other side, as far as one demands the existence of a mass gap in the graviton spectrum of the theory (in this case there are two bound states, a massless 4D graviton and a massive excitation separated from a continuous spectrum of massive Kaluza-Klein excitations) naked singularities arise at the boundaries of the Riemannian manifold, a fact that obligates one to impose unitary boundary conditions, which are equivalent to eliminating the continuous spectrum of gravitational massive modes, in order to render these singularities harmless from the physical point of view, providing in this way a viable model.

  20. Recovery of the Linearized 4D AdS and dS Schwarzschild Metric in the Karch-Randall Braneworld

    OpenAIRE

    2003-01-01

    We present a linearized treatment of the Karch-Randall braneworld where an AdS_4 or dS_4 brane is embedded in AdS_5. We examine the quasi-zero graviton mode in detail and reproduce the graviton mass by elementary means for the AdS_5 case. We also determine the axially symmetric, static excitations of the vacuum and demonstrate that they reproduce the 4D AdS_4 and dS_4 Schwarzschild metrics on the brane.

  1. Gravity in the brane-world for two-branes model with stabilized modulus

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takahiro; Montes, Xavier

    2000-08-28

    We present a complete scheme to discuss linear perturbations in the two-branes model of the Randall and Sundrum scenario with the stabilization mechanism proposed by Goldberger and Wise. We confirm that under the approximation of zero-mode truncation the induced metric on the branes reproduces that of the usual 4-dimensional Einstein gravity. We also present formulas to evaluate the mass spectrum and the contribution to the metric perturbations from all the Kaluza-Klein modes. We also conjecture that the model has tachyonic modes unless the background configuration for the bulk scalar field introduced to stabilize the distance between the two branes is monotonic in the fifth dimension.

  2. ONLINE PUBLISHING CURRENT SCENARIO

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2012-12-01

    Full Text Available This article attempts to unravel the current scenario in online publishing. Advent of internet has brought with it tremendous changes in the publishing industry. What was hither to an industry dominated by publisher has been thrown open to one and sundry. Online publishing has brought with it a reach which was hitherto never been imagined. In the normal course it would take at least a year to publish a manuscript. Online publishing has managed to bring this time down to a few weeks / at most a month. This article attempts to discusses the positives and perils of online publishing scenario.

  3. MIV Project: Mission scenario

    DEFF Research Database (Denmark)

    Ravazzotti, Mariolina T.; Jørgensen, John Leif; Thuesen, Gøsta

    1997-01-01

    Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions.......Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions....

  4. Crisis and Crisis Scenarios

    DEFF Research Database (Denmark)

    Larsen, Øjvind

    2016-01-01

    This special issue of Nordicum-Mediterraneum contains select proceedings from the third meeting of the Nordic Summer University research circle called “Crisis and Crisis Scenarios: Normativity, Possibilities and Dilemmas”, held April 9th — 12th, 2015 at the Lysebu Conference Centre in Oslo, Norway...

  5. The SAFRR Tsunami Scenario

    Science.gov (United States)

    Porter, K.; Jones, Lucile M.; Ross, Stephanie L.; Borrero, J.; Bwarie, J.; Dykstra, D.; Geist, Eric L.; Johnson, L.; Kirby, Stephen H.; Long, K.; Lynett, P.; Miller, K.; Mortensen, Carl E.; Perry, S.; Plumlee, G.; Real, C.; Ritchie, L.; Scawthorn, C.; Thio, H.K.; Wein, Anne; Whitmore, P.; Wilson, R.; Wood, Nathan J.; Ostbo, Bruce I.; Oates, Don

    2013-01-01

    The U.S. Geological Survey and several partners operate a program called Science Application for Risk Reduction (SAFRR) that produces (among other things) emergency planning scenarios for natural disasters. The scenarios show how science can be used to enhance community resiliency. The SAFRR Tsunami Scenario describes potential impacts of a hypothetical, but realistic, tsunami affecting California (as well as the west coast of the United States, Alaska, and Hawaii) for the purpose of informing planning and mitigation decisions by a variety of stakeholders. The scenario begins with an Mw 9.1 earthquake off the Alaska Peninsula. With Pacific basin-wide modeling, we estimate up to 5m waves and 10 m/sec currents would strike California 5 hours later. In marinas and harbors, 13,000 small boats are damaged or sunk (1 in 3) at a cost of $350 million, causing navigation and environmental problems. Damage in the Ports of Los Angeles and Long Beach amount to $110 million, half of it water damage to vehicles and containerized cargo. Flooding of coastal communities affects 1800 city blocks, resulting in $640 million in damage. The tsunami damages 12 bridge abutments and 16 lane-miles of coastal roadway, costing $85 million to repair. Fire and business interruption losses will substantially add to direct losses. Flooding affects 170,000 residents and workers. A wide range of environmental impacts could occur. An extensive public education and outreach program is underway, as well as an evaluation of the overall effort.

  6. Biomass Scenario Model

    Energy Technology Data Exchange (ETDEWEB)

    2015-09-01

    The Biomass Scenario Model (BSM) is a unique, carefully validated, state-of-the-art dynamic model of the domestic biofuels supply chain which explicitly focuses on policy issues, their feasibility, and potential side effects. It integrates resource availability, physical/technological/economic constraints, behavior, and policy. The model uses a system dynamics simulation (not optimization) to model dynamic interactions across the supply chain.

  7. MIV Project: Mission scenario

    DEFF Research Database (Denmark)

    Ravazzotti, Mariolina T.; Jørgensen, John Leif; Thuesen, Gøsta;

    1997-01-01

    Under the ESA contract #11453/95/NL/JG(SC), aiming at assessing the feasibility of Rendez-vous and docking of unmanned spacecrafts, a msiision scenario was defined. This report describes the secquence of manouvres and task allocations for such missions....

  8. Demand scenarios, worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A. [Massachusetts Inst. of Technology, Center for Technology, Policy and Industrial Development and the MIT Joint Program on the Science and Policy of Global Change, Cambridge, MA (United States)

    1996-11-01

    Existing methods are inadequate for developing aggregate (regional and global) and long-term (several decades) passenger transport demand scenarios, since they are mainly based on simple extensions of current patterns rather than causal relationships that account for the competition among transport modes (aircraft, automobiles, buses and trains) to provide transport services. The demand scenario presented in this paper is based on two empirically proven invariances of human behavior. First, transport accounts for 10 to 15 percent of household total expenditures for those owning an automobile, and around 5 percent for non-motorized households on average (travel money budget). Second, the mean time spent traveling is approximately one hour per capita per day (travel time budget). These two budgets constraints determine the dynamics of the scenario: rising income increases per capita expenditure on travel which, in turn, increase demand for mobility. Limited travel time constraints travelers to shift to faster transport systems. The scenario is initiated with the first integrated historical data set on traffic volume in 11 world regions and the globe from 1960 to 1990 for all major modes of motorized transport. World average per capita traffic volume, which was 1,800 kilometers in 1960 and 4,2090 in 1990, is estimated to rise to 7,900 kilometers in 2020 - given a modest average increase in Gross World Product of 1.9% per year. Higher economic growth rates in Asian regions result in an increase in regional per capita traffic volume up to a factor of 5.3 from 1990 levels. Modal splits continue shifting to more flexible and faster modes of transport. At one point, passenger cars can no longer satisfy the increasing demand for speed (i.e. rising mobility within a fixed time budget). In North America it is estimated that the absolute traffic volume of automobiles will gradually decline starting in the 2010s. (author) 13 figs., 6 tabs., 35 refs.

  9. Crisis and Crisis Scenarios

    DEFF Research Database (Denmark)

    Larsen, Øjvind

    2016-01-01

    This special issue of Nordicum-Mediterraneum contains select proceedings from the third meeting of the Nordic Summer University research circle called “Crisis and Crisis Scenarios: Normativity, Possibilities and Dilemmas”, held April 9th — 12th, 2015 at the Lysebu Conference Centre in Oslo, Norway....... The circle’s research program runs from 2014 to 2016 and is aimed at examining the concept of crisis as it is used today in academia and public discussion. In this collection of papers from the symposium we present some of the different ways in which the topic of the study group was addressed....

  10. Making use of scenarios : supporting scenario use in product design

    NARCIS (Netherlands)

    Anggreeni, Irene

    2010-01-01

    The discipline of Scenario-Based Product Design (SBPD) guides the use of scenarios in a product design process. As concrete narratives, scenarios could facilitate making explicit how users would use the designed product in their activities, allowing usability studies to be an integrated part of the

  11. Perturbatively deformed defects in Pöschl-Teller-driven scenarios for quantum mechanics

    Science.gov (United States)

    Bernardini, Alex E.; da Rocha, Roldão

    2016-07-01

    Pöschl-Teller-driven solutions for quantum mechanical fluctuations are triggered off by single scalar field theories obtained through a systematic perturbative procedure for generating deformed defects. The analytical properties concerning the quantum fluctuations in one-dimension, zero-mode states, first- and second-excited states, and energy density profiles are all obtained from deformed topological and non-topological structures supported by real scalar fields. Results are firstly derived from an integrated λϕ4 theory, with corresponding generalizations applied to starting λχ4 and sine-Gordon theories. By focusing our calculations on structures supported by the λϕ4 theory, the outcome of our study suggests an exact quantitative correspondence to Pöschl-Teller-driven systems. Embedded into the perturbative quantum mechanics framework, such a correspondence turns into a helpful tool for computing excited states and continuous mode solutions, as well as their associated energy spectrum, for quantum fluctuations of perturbatively deformed structures. Perturbative deformations create distinct physical scenarios in the context of exactly solvable quantum systems and may also work as an analytical support for describing novel braneworld universes embedded into a 5-dimensional gravity bulk.

  12. ILC Operating Scenarios

    CERN Document Server

    Barklow, T; Fujii, K; Gao, J; List, J; Walker, N; Yokoya, K

    2015-01-01

    The ILC Technical Design Report documents the design for the construction of a linear collider which can be operated at energies up to 500 GeV. This report summarizes the outcome of a study of possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes. The evolution of the physics outcomes is emphasized, including running initially at 500 GeV, then at 350 GeV and 250 GeV. The running scenarios have been chosen to optimize the Higgs precision measurements and top physics while searching for evidence for signals beyond the standard model, including dark matter. In addition to the certain precision physics on the Higgs and top that is the main focus of this study, there are scientific motivations that indicate the possibility for discoveries of new particles in the upcoming operations of the LHC or the early operation of the ILC. Follow-up studies of such discoveries could alter the plan for the centre-of-mass collision...

  13. 40 Years of Shell Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Shell has been using scenario planning for four decades. During that time these scenarios have helped the company and governments across the world to make better strategic choices. Scenarios provide lenses that help see future prospects more clearly, make richer judgments and be more sensitive to uncertainties. Discover how the Shell Scenarios team has helped guide decision makers at major moments in history and get a peek at the team future focus, including the intricate relationship between energy, water and food.

  14. Strategic Scenario Construction Made Easy

    DEFF Research Database (Denmark)

    Duus, Henrik Johannsen

    2016-01-01

    insights from the area of strategic forecasting (of which scenario planning is a proper subset) and experiences gained from a recent course in that area to develop a simpler, more direct, hands-on method for scenario construction and to provide several ideas for scenario construction that can be used...

  15. Scenario Planning in Higher Education.

    Science.gov (United States)

    Rieley, James B.

    1997-01-01

    Proposes scenario planning in preparing for the future of higher education. Delineates a methodology for effective scenario planning: identifying potential future scenarios; examining social, economic, political, environmental, and technological influences; exploring mental models while looking through systems maps, and developing potential…

  16. Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

    Energy Technology Data Exchange (ETDEWEB)

    Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

    2014-04-01

    Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

  17. Scenario development methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Eng, T. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, J. [Rock Engineering Consultants, Welwyn Garden City, Herts (United Kingdom); Stephansson, O. [Royal Inst. of Tech., Stockholm (Sweden). Div. of Engineering Geology; Skagius, K.; Wiborgh, M. [Kemakta, Stockholm (Sweden)

    1994-11-01

    In the period 1981-1994, SKB has studied several methodologies to systematize and visualize all the features, events and processes (FEPs) that can influence a repository for radioactive waste in the future. All the work performed is based on the terminology and basic findings in the joint SKI/SKB work on scenario development presented in the SKB Technical Report 89-35. The methodologies studied are (a) Event tree analysis, (b) Influence diagrams and (c) Rock Engineering Systems (RES) matrices. Each one of the methodologies is explained in this report as well as examples of applications. One chapter is devoted to a comparison between the two most promising methodologies, namely: Influence diagrams and the RES methodology. In conclusion a combination of parts of the Influence diagram and the RES methodology is likely to be a promising approach. 26 refs.

  18. Engaging Personas and Narrative Scenarios

    DEFF Research Database (Denmark)

    Nielsen, Lene

    2004-01-01

    design ideas. The concept of engaging personas and narrative scenario explores personas in the light of what what it is to identify with and have empathy with a character. The concept of narrative scenarios views the narrative as aid for exploration of design ideas. Both concepts incorporate a di...... a distinktion between creating, writing and reading. Keywords: personas, scenarios, user-centered design, HCI......design ideas. The concept of engaging personas and narrative scenario explores personas in the light of what what it is to identify with and have empathy with a character. The concept of narrative scenarios views the narrative as aid for exploration of design ideas. Both concepts incorporate...

  19. Strategic Scenario Construction Made Easy

    DEFF Research Database (Denmark)

    Duus, Henrik Johannsen

    2016-01-01

    insights from the area of strategic forecasting (of which scenario planning is a proper subset) and experiences gained from a recent course in that area to develop a simpler, more direct, hands-on method for scenario construction and to provide several ideas for scenario construction that can be used......Scenario planning is a well-known way to develop corporate strategy by creating multiple images of alternative futures. Yet although scenario planning grew from very hands-on strategy development efforts in the military and from operations research dedicated to solving practical problems, the use...... of scenarios in business has, in many cases, remained a cumbersome affair. Very often a large group of consultants, employees and staff is involved in the development of scenarios and strategies, thus making the whole process expensive in terms of time, money and human resources. In response, this article uses...

  20. LHC Upgrade Scenarios

    CERN Document Server

    Zimmermann, F

    2007-01-01

    The EU CARE-HHH and US-LARP studies for an LHC luminosity upgrade aim at increasing the peak luminosity by a factor of 10, to 1035 cm-2s-1. The luminosity can be raised by rebuilding the interaction regions (IRs) in combination with a consistent change of beam parameters. In addition to advanced low-beta quadrupoles, the upgraded IRs may accommodate other new elements such as slim s.c. dipoles or quadrupoles embedded deep inside the detectors, global low-angle crab cavities, and wire compensators of long-range beam-beam effects. Important constraints on the upgrade path are the maximum acceptable number of detector pile-up events, favoring many closely spaced bunches, and the heat load on the cold-magnet beam screens, pointing towards fewer and more intense bunches. In order to translate the increased peak luminosity into a correspondingly higher integrated luminosity, the upgrade of the LHC ring should be complemented by an upgrade of the injector complex. I will present preferred upgrade scenarios for the L...

  1. Learning from global emissions scenarios

    Science.gov (United States)

    O'Neill, Brian C.; Nakicenovic, Nebojsa

    2008-10-01

    Scenarios of global greenhouse gas emissions have played a key role in climate change analysis for over twenty years. Currently, several research communities are organizing to undertake a new round of scenario development in the lead-up to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). To help inform this process, we assess a number of past efforts to develop and learn from sets of global greenhouse gas emissions scenarios. We conclude that while emissions scenario exercises have likely had substantial benefits for participating modeling teams and produced insights from individual models, learning from the exercises taken as a whole has been more limited. Model comparison exercises have typically focused on the production of large numbers of scenarios while investing little in assessing the results or the production process, perhaps on the assumption that later assessment efforts could play this role. However, much of this assessment potential remains untapped. Efforts such as scenario-related chapters of IPCC reports have been most informative when they have gone to extra lengths to carry out more specific comparison exercises, but in general these assessments do not have the remit or resources to carry out the kind of detailed analysis of scenario results necessary for drawing the most useful conclusions. We recommend that scenario comparison exercises build-in time and resources for assessing scenario results in more detail at the time when they are produced, that these exercises focus on more specific questions to improve the prospects for learning, and that additional scenario assessments are carried out separately from production exercises. We also discuss the obstacles to better assessment that might exist, and how they might be overcome. Finally, we recommend that future work include much greater emphasis on understanding how scenarios are actually used, as a guide to improving scenario production.

  2. The changing nutrition scenario

    Directory of Open Access Journals (Sweden)

    C Gopalan

    2013-01-01

    Full Text Available The past seven decades have seen remarkable shifts in the nutritional scenario in India. Even up to the 1950s severe forms of malnutrition such as kwashiorkar and pellagra were endemic. As nutritionists were finding home-grown and common-sense solutions for these widespread problems, the population was burgeoning and food was scarce. The threat of widespread household food insecurity and chronic undernutrition was very real. Then came the Green Revolution. Shortages of food grains disappeared within less than a decade and India became self-sufficient in food grain production. But more insidious problems arising from this revolution were looming, and cropping patterns giving low priority to coarse grains and pulses, and monocropping led to depletion of soil nutrients and ′Green Revolution fatigue′. With improved household food security and better access to health care, clinical manifestations of severe malnutrition virtually disappeared. But the decline in chronic undernutrition and "hidden hunger" from micronutrient deficiencies was slow. On the cusp of the new century, an added factor appeared on the nutritional scene in India. With steady urban migration, upward mobility out of poverty, and an increasingly sedentary lifestyle because of improvements in technology and transport, obesity rates began to increase, resulting in a dual burden. Measured in terms of its performance in meeting its Millennium Development Goals, India has fallen short. Despite its continuing high levels of poverty and illiteracy, India has a huge demographic potential in the form of a young population. This advantage must be leveraged by investing in nutrition education, household access to nutritious diets, sanitary environment and a health-promoting lifestyle. This requires co-operation from all the stakeholders, including governments, non government organizations, scientists and the people at large.

  3. Automated Analysis of Infinite Scenarios

    DEFF Research Database (Denmark)

    Buchholtz, Mikael

    2005-01-01

    The security of a network protocol crucially relies on the scenario in which the protocol is deployed. This paper describes syntactic constructs for modelling network scenarios and presents an automated analysis tool, which can guarantee that security properties hold in all of the (infinitely many......) instances of a scenario. The tool is based on control flow analysis of the process calculus LySa and is applied to the Bauer, Berson, and Feiertag protocol where is reveals a previously undocumented problem, which occurs in some scenarios but not in other....

  4. Scenario Planning and Collection Development.

    Science.gov (United States)

    Giesecke, Joan

    1999-01-01

    Discussion of the future of library collection development and the need for planning focuses on the technique of scenario planning and discusses the results of scenario planning at the University of NebraskaLincoln that examined collection development and digital information. (LRW)

  5. Supersymmetric Brane-Worlds

    CERN Document Server

    Alonso-Alberca, N; Ortín, Tomas

    2000-01-01

    We present warped metrics which solve Einstein equations with arbitrary cosmological constants in both in upper and lower dimensions. When the lower-dimensional metric is the maximally symmetric one compatible with the chosen value of the cosmological constant, the upper-dimensional metric is also the maximally symmetric one and there is maximal unbroken supersymmetry as well. We then introduce brane sources and find solutions with analogous properties, except for supersymmetry, which is generically broken in the orbifolding procedure (one half is preserved in two special cases), and analyze metric perturbations in these backgrounds

  6. Braneworld Flux Inflation

    CERN Document Server

    Kanno, S; Wands, D; Kanno, Sugumi; Soda, Jiro; Wands, David

    2005-01-01

    We propose a geometrical model of brane inflation where inflation is driven by the flux generated by opposing brane charges and terminated by the collision of the branes, with charge annihilation. We assume the collision process is completely inelastic and the kinetic energy is transformed into the thermal energy after collision. Thereafter the two branes coalesce together and behave as a single brane universe with zero effective cosmological constant. In the Einstein frame, the 4-dimensional effective theory changes abruptly at the collision point. Therefore, our inflationary model is necessarily 5-dimensional in nature. As the collision process has no singularity in 5-dimensional gravity, we can follow the evolution of fluctuations during the whole history of the universe. It turns out that the radion field fluctuations have a steeply tilted, red spectrum, while the primordial gravitational waves have a flat spectrum. Instead, primordial density perturbations could be generated by a curvaton mechanism.

  7. Holographic Dark Energy from a Modified GBIG Scenario

    CERN Document Server

    Nozari, Kourosh

    2009-01-01

    We construct a holographic dark energy model in a braneworld setup that gravity is induced on the brane embedded in a bulk with Gauss-Bonnet curvature term. We include possible modification of the induced gravity and its coupling with a canonical scalar field on the brane. Through a perturbational approach to calculate the effective gravitation constant on the brane, we examine the outcome of this model as a candidate for holographic dark energy.

  8. Social Foundation of Scenario Planning

    DEFF Research Database (Denmark)

    Spaniol, Matthew Jon; Rowland, Nicholas James

    2017-01-01

    In this article, the authors establish that models of scenario planning typically involve a series of phases, stages, or steps that imply a sequenced (i.e., linear or chronological) process. Recursive models, in contrast, allow phases to repeat, thus, incorporating iteration. The authors......” phase of a planning process with a non-governmental organization in Denmark. The upshot for facilitators is practical insight into how transition between phases and phase iteration in scenario planning can be identified, leveraged, and, thus, managed. The upshot for scholars is a related insight...... into why scenario planning is a kind of laboratory for futures studies wherein the future is experimented upon....

  9. Social Foundation of Scenario Planning

    DEFF Research Database (Denmark)

    Spaniol, Matthew Jon; Rowland, Nicholas James

    2017-01-01

    from science and technology studies (STS) on knowledge production, the authors explain transition from one phase to the next and iteration between and within phases based on social negotiation. To this end, the authors examine the interplay between the “scenario development” phase and the “scenario use......” phase of a planning process with a non-governmental organization in Denmark. The upshot for facilitators is practical insight into how transition between phases and phase iteration in scenario planning can be identified, leveraged, and, thus, managed. The upshot for scholars is a related insight...

  10. Earthquake Hazards Program: Earthquake Scenarios

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A scenario represents one realization of a potential future earthquake by assuming a particular magnitude, location, and fault-rupture geometry and estimating...

  11. Scenario Planning as Organizational Intervention

    DEFF Research Database (Denmark)

    Balarezo, Jose; Nielsen, Bo Bernhard

    2017-01-01

    Purpose: This paper identifies four areas in need of future research to enhance our theoretical understanding of scenario planning, and sets the basis for future empirical examination of its effects on individual and organizational level outcomes. Design/methodology/approach: This paper organizes...... existing contributions on scenario planning within a new consolidating framework that includes antecedents, processes, and outcomes. The proposed framework allows for integration of the extant literature on scenario planning from a wide variety of fields, including strategic management, finance, human...... resource management, operations management, and psychology. Findings: This study contributes to research by offering a coherent and consistent framework for understanding scenario planning as a dynamic process. As such, it offers future researchers with a systematic way to ascertain where a particular...

  12. Scenarios and activities (Chapter 1)

    CSIR Research Space (South Africa)

    Burns, Mike

    2016-01-01

    Full Text Available The description and quantification of the shale gas-related activities presented in this Chapter informs the assessment of ecological and social risk addressed in other Chapters. For the Exploration Only scenario, activities that will manifest...

  13. Le metodologie dello scenario parecipato

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The article presents paradigm, historical background and framework of participatory scenario planning. In addition an example of the method used in Malaysia is described and the possible strenghts and weaknesses is reflected......The article presents paradigm, historical background and framework of participatory scenario planning. In addition an example of the method used in Malaysia is described and the possible strenghts and weaknesses is reflected...

  14. Thick braneworlds generated by a non-minimally coupled scalar field and a Gauss-Bonnet term: conditions for localization of gravity

    CERN Document Server

    Herrera-Aguilar, Alfredo; Mora-Luna, Refugio Rigel; Quiros, Israel

    2011-01-01

    We consider warped five-dimensional thick braneworlds with four-dimensional Poincare invariance originated from bulk scalar matter non-minimally coupled to gravity plus a Gauss-Bonnet term. The background field equations as well as the perturbed equations are investigated. A relationship between 4D and 5D Planck masses is studied in general terms. By imposing finiteness of the 4D Planck mass and regularity of the geometry, the localization properties of the tensor modes of the perturbed geometry are analyzed to first order, for a wide class of solutions. In order to explore the gravity localization properties for this model, the normalizability condition for the lowest level of the tensor fluctuations is analyzed. It is found that for the examined class of solutions, gravity in 4 dimensions is recovered if and only if the curvature invariants are regular and the 4D Planck mass is finite. It turns out that both the addition of the Gauss-Bonnet term and the non-minimal coupling between the scalar field and grav...

  15. Future scenarios to inspire innovation

    DEFF Research Database (Denmark)

    De Smedt, Peter; Borch, Kristian; Fuller, Ted

    2013-01-01

    . Due to the social dynamics of innovation, new socio-technical subsystems are emerging, however there is lack of exploitation of novel ideas and sustainable solutions to address these grand challenges. In this paper we argue that issues of how knowledge is represented can have a part in this lack...... the grand challenges. By analyzing several scenario cases, elements of good practices and principles on how to strengthen innovation systems through future scenarios are identified. This is needed because innovation itself needs to be oriented along more sustainable pathways enabling transformations...

  16. NEC-2020 emission reduction scenarios

    DEFF Research Database (Denmark)

    Slentø, Erik; Nielsen, Ole-Kenneth; Hoffmann, Leif

    The upcoming NEC-2020 EU directive sets up emission ceilings for NOX, SO2, NH3, NMVOC and PM in order to meet the environmental exposure targets of the Thematic Strategy. This report contains an assessment of intermediary emission reduction scenarios for Denmark, computed by the GAINS model 2007......, which serves as the basis for the pending negotiations in EU. The assessment is brought up to date by including a brief evaluation of the new reduction scenarios published in 2008, founding the European Commission NEC-2020 directive proposal....

  17. Tachyon-Warm Intermediate and Logamediate Inflation in the Brane-World Model in the Light of Planck Data

    CERN Document Server

    Kamali, Vahid

    2015-01-01

    Tachyon inflationary universe model on the brane in the context of warm inflation is studied. In slow-roll approximation and in longitudinal gauge, we find the primoradial perturbation spectrums for this scenario. We also present the general expressions of the tensor-scalar ratio, scalar spectral index and its running. We develop our model by using exponential potential, the characteristics of this model are calculated in great details. We also study our model in the context of intermediate (where scale factor expands as: $a=a_0\\exp(At^f)$) and logamediate (where the scale factor expands as: $a=a_0\\exp(A[\\ln t]^{\

  18. Scenario Based Network Infrastructure Planning

    DEFF Research Database (Denmark)

    Knudsen, Thomas Phillip; Pedersen, Jens Myrup; Madsen, Ole Brun

    2005-01-01

    The paper presents a method for IT infrastructure planning that take into account very long term developments in usages. The method creates a scenario for a final, time independent stage in the planning process. The method abstracts relevant modelling factors from available information...

  19. Scenario Based Network Infrastructure Planning

    DEFF Research Database (Denmark)

    Knudsen, Thomas Phillip; Pedersen, Jens Myrup; Madsen, Ole Brun

    2005-01-01

    The paper presents a method for IT infrastructure planning that take into account very long term developments in usages. The method creates a scenario for a final, time independent stage in the planning process. The method abstracts relevant modelling factors from available information...

  20. Program Analysis Scenarios in Rascal

    NARCIS (Netherlands)

    M.A. Hills (Mark); P. Klint (Paul); J.J. Vinju (Jurgen); F. Durán

    2012-01-01

    textabstractRascal is a meta programming language focused on the implementation of domain-specific languages and on the rapid construction of tools for software analysis and software transformation. In this paper we focus on the use of Rascal for software analysis. We illustrate a range of scenarios

  1. Particle production in Ekpyrotic scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Hipólito-Ricaldi, W.S. [Physics Department, McGill University,Montreal, QC, H3A 2T8 (Canada); Departamento de Ciências Naturais, Universidade Federal do Espirito Santo,Rodovia BR 101 Norte, km. 60, Campus de São Mateus, CEP 29932-540,São Mateus, Espirito Santo (Brazil); Brandenberger, Robert [Physics Department, McGill University,Montreal, QC, H3A 2T8 (Canada); Institute for Theoretical Studies, ETH Zürich,CH-8092 Zürich (Switzerland); Ferreira, Elisa G.M.; Graef, L.L. [Physics Department, McGill University,Montreal, QC, H3A 2T8 (Canada)

    2016-11-09

    We consider Parker particle production in the Ekpyrotic scenario (in particular in the New Ekpyrotic model) and show that the density of particles produced by the end of the phase of Ekpyrotic contraction can be sufficient to lead to a hot state of matter after the bounce. Hence, no separate reheating mechanism is necessary.

  2. Scenario Writing: A Therapeutic Application.

    Science.gov (United States)

    Haddock, Billy D.

    1989-01-01

    Introduces scenario writing as useful therapeutic technique. Presents case study of woman in midst of divorce and custody fight to illustrate context in which technique was applied. Suggests additional applications. Concludes that good response is more likely for clients who possess good writing skills although other clients may use their own…

  3. Future Scenarios and Environmental Education

    OpenAIRE

    Kopnina, H.N.

    2014-01-01

    This article explores a number of questions about visions of the future and their implications for environmental education (EE). If the future were known, what kind of actions would be needed to maintain the positive aspects and reverse the negative ones? How could these actions be translated into the aims of EE? Three future scenarios are discussed: the limits to growth (the great tragedy and demise); sustainable development and ecological modernization (hope and innovation); and the Anthrop...

  4. Scenarios and Strategies for Africa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    In 2011, IRENA will start developing scenarios and strategies for Africa. This is a pilot study for a project that will ultimately encompass the whole world. The selection of Africa first indicates the priority that the IRENA work programme places on the continent. In the framework of the 2011 IRENA work programme, the analysis of scenarios and strategies will feed into the renewables readiness assessment, which will assess policy priorities and best practices in renewable energy policy-making. This, in turn, will be the basis for financing investment and capacity building activities. Energy policy advice must consider issues, such as the structure of energy supply and demand, the past and future energy trends, renewable energy resources, energy economics and technology access. Scenarios and strategies are key tools for such an analysis. Regional and national differences must be considered and individual sectors and end-use categories further analysed. These include power generation, cooking, heating, industrial process heat, and transport. Urban and rural solutions will be dealt with separately, as well as centralised and decentralised solutions. The analysis will cover issues, such as potentials, technology, supply chains and investment needs.

  5. Simulating geometrically complex blast scenarios

    Directory of Open Access Journals (Sweden)

    Ian G. Cullis

    2016-04-01

    Full Text Available The effects of blast waves generated by energetic and non-energetic sources are of continuing interest to the ballistics research community. Modern conflicts are increasingly characterised by asymmetric urban warfare, with improvised explosive devices (IEDs often playing a dominant role on the one hand and an armed forces requirement for minimal collateral effects from their weapons on the other. These problems are characterised by disparate length- and time-scales and may also be governed by complex physics. There is thus an increasing need to be able to rapidly assess and accurately predict the effects of energetic blast in topologically complex scenarios. To this end, this paper presents a new QinetiQ-developed advanced computational package called EAGLE-Blast, which is capable of accurately resolving the generation, propagation and interaction of blast waves around geometrically complex shapes such as vehicles and buildings. After a brief description of the numerical methodology, various blast scenario simulations are described and the results compared with experimental data to demonstrate the validation of the scheme and its ability to describe these complex scenarios accurately and efficiently. The paper concludes with a brief discussion on the use of the code in supporting the development of algorithms for fast running engineering models.

  6. Simulating geometrically complex blast scenarios

    Institute of Scientific and Technical Information of China (English)

    Ian G. CULLIS; Nikos NIKIFORAKIS; Peter FRANKL; Philip BLAKELY; Paul BENNETT; Paul GREENWOOD

    2016-01-01

    The effects of blast waves generated by energetic and non-energetic sources are of continuing interest to the ballistics research community. Modern conflicts are increasingly characterised by asymmetric urban warfare, with improvised explosive devices (IEDs) often playing a dominant role on the one hand and an armed forces requirement for minimal collateral effects from their weapons on the other. These problems are characterised by disparate length-and time-scales and may also be governed by complex physics. There is thus an increasing need to be able to rapidly assess and accurately predict the effects of energetic blast in topologically complex scenarios. To this end, this paper presents a new QinetiQ-developed advanced computational package called EAGLE-Blast, which is capable of accurately resolving the generation, propagation and interaction of blast waves around geometrically complex shapes such as vehicles and buildings. After a brief description of the numerical methodology, various blast scenario simulations are described and the results compared with experimental data to demonstrate the validation of the scheme and its ability to describe these complex scenarios accurately and efficiently. The paper concludes with a brief discussion on the use of the code in supporting the development of algorithms for fast running engineering models.

  7. Clean energy scenarios for Australia

    Energy Technology Data Exchange (ETDEWEB)

    Saddler, H. [Energy Strategies Pty Ltd., Manuka (Australia); Diesendorf, M. [University of New South Wales, Sydney (Australia). Institute of Environmental Studies; Denniss, R. [Parliament House, Canberra (Australia). Office of Senator Bob Brown

    2007-02-15

    Australia, a major producer and user of coal, has the highest per capita greenhouse gas emissions in the industrialised world. This study investigates whether in theory such a 'fossil-fuel dependent' country could achieve a 50% reduction in CO{sub 2} emissions from stationary energy by 2040, compared with its 2001 emissions. To do this scenarios are developed, using a combination of forecasting and backcasting methods, under conditions of continuing economic growth and a restriction to the use of existing commercial technologies with small improvements. The principal scenario achieves the above target by implementing on the demand-side a medium-level of efficient energy use and substantial solar hot water together with a supply side combination of mainly natural gas, bioenergy and wind power. In doing so the scenario also achieves a 78% reduction in CO{sub 2} emissions from electricity. Within the large uncertainties in future prices, it is possible that the economic savings from efficient energy use could pay for all or a large part of the additional costs of renewable energy. (author)

  8. Scenarios for the LHC Upgrade

    CERN Document Server

    Scandale, Walter

    2008-01-01

    The projected lifetime of the LHC low-beta quadrupoles, the evolution of the statistical error halving time, and the physics potential all call for an LHC luminosity upgrade by the middle of the coming decade. In the framework of the CARE-HHH network three principal scenarios have been developed for increasing the LHC peak luminosity by more than a factor of 10, to values above 1035 cm−2s−1. All scenarios imply a rebuilding of the high-luminosity interaction regions (IRs) in combination with a consistent change of beam parameters. However, their respective features, bunch structures, IR layouts, merits and challenges, and luminosity variation with β∗ differ substantially. In all scenarios luminosity leveling during a store would be advantageous for the physics experiments. An injector upgrade must complement the upgrade measures in the LHC proper in order to provide the beam intensity and brightness needed as well as to reduce the LHC turnaround time for higher integrated luminosity.

  9. Europa Explorer Operational Scenarios Development

    Science.gov (United States)

    Lock, Robert E.; Pappalardo, Robert T.; Clark, Karla B.

    2008-01-01

    In 2007, NASA conducted four advanced mission concept studies for outer planets targets: Europa, Ganymede, Titan and Enceladus. The studies were conducted in close cooperation with the planetary science community. Of the four, the Europa Explorer Concept Study focused on refining mission options, science trades and implementation details for a potential flagship mission to Europa in the 2015 timeframe. A science definition team (SDT) was appointed by NASA to guide the study. A JPL-led engineering team worked closely with the science team to address 3 major focus areas: 1) credible cost estimates, 2) rationale and logical discussion of radiation risk and mitigation approaches, and 3) better definition and exploration of science operational scenario trade space. This paper will address the methods and results of the collaborative process used to develop Europa Explorer operations scenarios. Working in concert with the SDT, and in parallel with the SDT's development of a science value matrix, key mission capabilities and constraints were challenged by the science and engineering members of the team. Science goals were advanced and options were considered for observation scenarios. Data collection and return strategies were tested via simulation, and mission performance was estimated and balanced with flight and ground system resources and science priorities. The key to this successful collaboration was a concurrent development environment in which all stakeholders could rapidly assess the feasibility of strategies for their success in the full system context. Issues of science and instrument compatibility, system constraints, and mission opportunities were treated analytically and objectively leading to complementary strategies for observation and data return. Current plans are that this approach, as part of the system engineering process, will continue as the Europa Explorer Concept Study moves toward becoming a development project.

  10. Scenarios for the future; Framtidsscenarier

    Energy Technology Data Exchange (ETDEWEB)

    Haegermark, H.; Bergmark, M.

    1995-06-01

    This project aims primarily to give a basis for the joint R and D program for the Swedish electric utility industry, in the form of pictures of the future up to 2020. The work was performed during four seminars in a group of managers and R and D planners. The four scenarios differ mainly in the assumptions of high or low economic growth and on market or political rule. Assumptions on essential uncertainties about the future have been combined in a consistent manner, e.g. on the structure of the utility industry, the role of nuclear power, the importance of the greenhouse gas issue, the influence of new technology developments and on changes of values in society. Certain other development appear in all scenarios, e.g. the impact of information technology throughout society, the internationalization of business in general and industrial production in particular, considerations for the environment and care for natural resources. The four scenarios are: `Technology on the throne` (market rule/high growth); `Intense competition` (market rule/low growth); `Monopoly takes over` (political rule/high growth); and `Green local society` (political rule/low growth). Some of the important factors pointed out by the study are: Increased customer mobility between regions and countries; The impact of information technology; Societal value changes; Sustainable development as an important driving force; Structure of the utility industry. Diversifying into new services. New players; Access to knowledge and competence; Ways for handling the greenhouse gas problem; Preparedness for nuclear power phase-out. 12 figs, 6 tabs

  11. Spent fuel receipt scenarios study

    Energy Technology Data Exchange (ETDEWEB)

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs.

  12. Scenarios for coastal vulnerability assessment

    Science.gov (United States)

    Nicholls, Robert J.; Woodroffe, Colin D.; Burkett, Virginia; Hay, John; Wong, Poh Poh; Nurse, Leonard; Wolanski, Eric; McLusky, Donald S.

    2011-01-01

    Coastal vulnerability assessments tend to focus mainly on climate change and especially on sea-level rise. Assessment of the influence of nonclimatic environmental change or socioeconomic change is less well developed and these drivers are often completely ignored. Given that the most profound coastal changes of the twentieth century due to nonclimate drivers are likely to continue through the twenty-first century, this is a major omission. It may result in not only overstating the importance of climate change but also overlooking significant interactions of climate change and other drivers. To support the development of policies relating to climate change and coastal management, integrated assessments of climatic change in coastal areas are required, including the effects of all the relevant drivers. This chapter explores the development of scenarios (or "plausible futures") of relevant climate and nonclimate drivers that can be used for coastal analysis, with an emphasis on the nonclimate drivers. It shows the importance of analyzing the impacts of climate change and sea-level rise in a broader context of coastal change and all its drivers. This will improve the analysis of impacts, key vulnerabilities, and adaptation needs and, hence, inform climate and coastal policy. Stakeholder engagement is important in the development of scenarios, and the underlying assumptions need to be explicit, transparent, and open to scientific debate concerning their uncertainties/realism and likelihood.

  13. Scenario Development for Information Operations (IO) Experimentation

    Science.gov (United States)

    2003-07-10

    country called DYSLEXIA , whose government has been making threats to invade and appropriate a region of its neighbouring country, ABSTEMIA, which is...Network Measures and Metrics 18 Conclusion Scenarios - Tailoring, Framework, Families of Scenario Experiments - Measures, Humans, Objectives Networks

  14. Scenario Development for the Southwestern United States

    Science.gov (United States)

    Mahmoud, M.; Gupta, H.; Stewart, S.; Liu, Y.; Hartmann, H.; Wagener, T.

    2006-12-01

    The primary goal of employing a scenario development approach for the U.S. southwest is to inform regional policy by examining future possibilities related to regional vegetation change, water-leasing, and riparian restoration. This approach is necessary due to a lack of existing explicit water resources application of scenarios to the entire southwest region. A formal approach for scenario development is adopted and applied towards water resources issues within the arid and semi-arid regions of the U.S. southwest following five progressive and reiterative phases: scenario definition, scenario construction, scenario analysis, scenario assessment, and risk management. In the scenario definition phase, the inputs of scientists, modelers, and stakeholders were collected in order to define and construct relevant scenarios to the southwest and its water sustainability needs. From stakeholder-driven scenario workshops and breakout sessions, the three main axes of principal change were identified to be climate change, population development patterns, and quality of information monitoring technology. Based on the extreme and varying conditions of these three main axes, eight scenario narratives were drafted to describe the state of each scenario's respective future and the events which led to it. Events and situations are described within each scenario narrative with respect to key variables; variables that are both important to regional water resources (as distinguished by scientists and modelers), and are good tracking and monitoring indicators of change. The current phase consists of scenario construction, where the drafted scenarios are re-presented to regional scientists and modelers to verify that proper key variables are included (or excluded) from the eight narratives. The next step is to construct the data sets necessary to implement the eight scenarios on the respective computational models of modelers investigating vegetation change, water-leasing, and riparian

  15. The Narrative Aspect of Scenario Building

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2008-01-01

    The application of narrative scenarios in engineering or socio-technical systems provides an important link between general ideas and specification of technical system requirements. The chapter explores how the narrative approach can enrich the scenario 'skeleton. In addition, criteria are sugges......The application of narrative scenarios in engineering or socio-technical systems provides an important link between general ideas and specification of technical system requirements. The chapter explores how the narrative approach can enrich the scenario 'skeleton. In addition, criteria...

  16. Development and Change through Scenario Planning

    Science.gov (United States)

    Chermack, Thomas J.; Walton, John S.

    2004-01-01

    This paper examines the role of scenario planning as a development and change intervention. To do so, this article provides an overview of scenario planning and an overview of development and change in organizations. The article then builds on the philosophical orientations of development and change through scenario planning introducing the…

  17. Industrial research for transmutation scenarios

    Science.gov (United States)

    Camarcat, Noel; Garzenne, Claude; Le Mer, Joël; Leroyer, Hadrien; Desroches, Estelle; Delbecq, Jean-Michel

    2011-04-01

    This article presents the results of research scenarios for americium transmutation in a 22nd century French nuclear fleet, using sodium fast breeder reactors. We benchmark the americium transmutation benefits and drawbacks with a reference case consisting of a hypothetical 60 GWe fleet of pure plutonium breeders. The fluxes in the various parts of the cycle (reactors, fabrication plants, reprocessing plants and underground disposals) are calculated using EDF's suite of codes, comparable in capabilities to those of other research facilities. We study underground thermal heat load reduction due to americium partitioning and repository area minimization. We endeavor to estimate the increased technical complexity of surface facilities to handle the americium fluxes in special fuel fabrication plants, americium fast burners, special reprocessing shops, handling equipments and transport casks between those facilities.

  18. The ShakeOut Scenario

    Science.gov (United States)

    Jones, Lucile M.; Bernknopf, Richard; Cox, Dale; Goltz, James; Hudnut, Kenneth; Mileti, Dennis; Perry, Suzanne; Ponti, Daniel; Porter, Keith; Reichle, Michael; Seligson, Hope; Shoaf, Kimberley; Treiman, Jerry; Wein, Anne

    2008-01-01

    This is the initial publication of the results of a cooperative project to examine the implications of a major earthquake in southern California. The study comprised eight counties: Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura. Its results will be used as the basis of an emergency response and preparedness exercise, the Great Southern California ShakeOut, and for this purpose we defined our earthquake as occurring at 10:00 a.m. on November 13, 2008. As members of the southern California community use the ShakeOut Scenario to plan and execute the exercise, we anticipate discussion and feedback. This community input will be used to refine our assessment and will lead to a formal publication in early 2009. Our goal in the ShakeOut Scenario is to identify the physical, social and economic consequences of a major earthquake in southern California and in so doing, enable the users of our results to identify what they can change now?before the earthquake?to avoid catastrophic impact after the inevitable earthquake occurs. To do so, we had to determine the physical damages (casualties and losses) caused by the earthquake and the impact of those damages on the region?s social and economic systems. To do this, we needed to know about the earthquake ground shaking and fault rupture. So we first constructed an earthquake, taking all available earthquake research information, from trenching and exposed evidence of prehistoric earthquakes, to analysis of instrumental recordings of large earthquakes and the latest theory in earthquake source physics. We modeled a magnitude (M) 7.8 earthquake on the southern San Andreas Fault, a plausible event on the fault most likely to produce a major earthquake. This information was then fed forward into the rest of the ShakeOut Scenario. The damage impacts of the scenario earthquake were estimated using both HAZUS-MH and expert opinion through 13 special studies and 6 expert panels, and fall into four

  19. Development scenario for laser fusion

    Energy Technology Data Exchange (ETDEWEB)

    Maniscalco, J.A.; Hovingh, J.; Buntzen, R.R.

    1976-03-30

    This scenario proposes establishment of test and engineering facilities to (1) investigate the technological problems associated with laser fusion, (2) demonstrate fissile fuel production, and (3) demonstrate competitive electrical power production. Such facilities would be major milestones along the road to a laser-fusion power economy. The relevant engineering and economic aspects of each of these research and development facilities are discussed. Pellet design and gain predictions corresponding to the most promising laser systems are presented for each plant. The results show that laser fusion has the potential to make a significant contribution to our energy needs. Beginning in the early 1990's, this new technology could be used to produce fissile fuel, and after the turn of the century it could be used to generate electrical power.

  20. Radiation Detection Computational Benchmark Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, Mark W.; Casella, Andrew M.; Wittman, Richard S.; McDonald, Ben S.

    2013-09-24

    Modeling forms an important component of radiation detection development, allowing for testing of new detector designs, evaluation of existing equipment against a wide variety of potential threat sources, and assessing operation performance of radiation detection systems. This can, however, result in large and complex scenarios which are time consuming to model. A variety of approaches to radiation transport modeling exist with complementary strengths and weaknesses for different problems. This variety of approaches, and the development of promising new tools (such as ORNL’s ADVANTG) which combine benefits of multiple approaches, illustrates the need for a means of evaluating or comparing different techniques for radiation detection problems. This report presents a set of 9 benchmark problems for comparing different types of radiation transport calculations, identifying appropriate tools for classes of problems, and testing and guiding the development of new methods. The benchmarks were drawn primarily from existing or previous calculations with a preference for scenarios which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22. From a technical perspective, the benchmarks were chosen to span a range of difficulty and to include gamma transport, neutron transport, or both and represent different important physical processes and a range of sensitivity to angular or energy fidelity. Following benchmark identification, existing information about geometry, measurements, and previous calculations were assembled. Monte Carlo results (MCNP decks) were reviewed or created and re-run in order to attain accurate computational times and to verify agreement with experimental data, when present. Benchmark information was then conveyed to ORNL in order to guide testing and development of hybrid calculations. The results of those ADVANTG calculations were then sent to PNNL for

  1. Towards a user's guide to scenarios - a report on scenario types and scenario techniques

    Energy Technology Data Exchange (ETDEWEB)

    Boerjeson, Lena; Hoejer, Mattias; Dreborg, Karl-Henrik; Finnveden, Goeran [Royal Inst. of Technology, Stockholm (Sweden). Environmental Strategies Research - fms; Ekvall, Tomas [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy and Environment

    2005-11-01

    Futures studies consist of a vast variation of studies and approaches. The aim of this paper is to contribute to the understanding of for what purposes scenarios are useful and what methods and procedures are useful for furthering these purposes. We present a scenario typology with an aim to better suit the context in which the scenarios are used. The scenario typology is combined with a new way of looking at scenario techniques, i.e. practical methods and procedures for scenario development. Finally, we look at the usefulness of scenarios in the light of the scenario typology and the scenario techniques. As a start, we distinguish between three main categories of scenario studies. The classification is based on the principal questions we believe a user may want to pose about the future. The resolution is then increased by letting each category contain two different scenario types. These are distinguished by different angles of approach of the questions defining the categories. The first question, What will happen?, is responded to by Predictive scenarios. In fact, the response to a question like this will always be conditional, e.g. of a stable and peaceful world, or by a certain continuous development of some kind. We have utilized this fact when defining the two predictive scenario types, Forecasts and What-if scenarios. The second question, What can happen?, is responded to by Explorative scenarios. The scenarios are thus explorations of what might happen in the future, regardless of beliefs of what is likely to happen or opinions of what is desirable. This category is further divided into external and strategic scenarios. The final question, How can a specific target be reached?, is responded to by Normative scenarios. Such studies are explicitly normative, since they take a target as a starting point. They are often directed towards how the target could be reached. This category is divided into preserving and transforming scenarios. If the user wants to

  2. Web Based Tool for Mission Operations Scenarios

    Science.gov (United States)

    Boyles, Carole A.; Bindschadler, Duane L.

    2008-01-01

    A conventional practice for spaceflight projects is to document scenarios in a monolithic Operations Concept document. Such documents can be hundreds of pages long and may require laborious updates. Software development practice utilizes scenarios in the form of smaller, individual use cases, which are often structured and managed using UML. We have developed a process and a web-based scenario tool that utilizes a similar philosophy of smaller, more compact scenarios (but avoids the formality of UML). The need for a scenario process and tool became apparent during the authors' work on a large astrophysics mission. It was noted that every phase of the Mission (e.g., formulation, design, verification and validation, and operations) looked back to scenarios to assess completeness of requirements and design. It was also noted that terminology needed to be clarified and structured to assure communication across all levels of the project. Attempts to manage, communicate, and evolve scenarios at all levels of a project using conventional tools (e.g., Excel) and methods (Scenario Working Group meetings) were not effective given limitations on budget and staffing. The objective of this paper is to document the scenario process and tool created to offer projects a low-cost capability to create, communicate, manage, and evolve scenarios throughout project development. The process and tool have the further benefit of allowing the association of requirements with particular scenarios, establishing and viewing relationships between higher- and lower-level scenarios, and the ability to place all scenarios in a shared context. The resulting structured set of scenarios is widely visible (using a web browser), easily updated, and can be searched according to various criteria including the level (e.g., Project, System, and Team) and Mission Phase. Scenarios are maintained in a web-accessible environment that provides a structured set of scenario fields and allows for maximum

  3. Commercial Mobile Alert Service (CMAS) Scenarios

    Science.gov (United States)

    2012-05-01

    Nord 2009]. Figure 1 shows the relationship between mission thread scenarios and QA scenarios. Mission thread scenarios contain steps that...Execute Health Severe Immediate Observed Flash Flood "No Special Handling" Actual Assess Meteorological Severe Expected Likely Tsunami "No Special...projects.shtm#6 (2011). CMU/SEI-2012-SR-020 | 49 [ Nord 2009] Nord , R.; Bergey, J.; Blanchette, S.; & Klein, M. “The Impact of Conducting ATAM

  4. Renormalization-group improved inflationary scenarios

    CERN Document Server

    Pozdeeva, E O

    2016-01-01

    The possibility to construct an inflationary scenario for renormalization-group improved potentials corresponding to the Higgs sector of quantum field models is investigated. Taking into account quantum corrections to the renormalization-group potential which sums all leading logs of perturbation theory is essential for a successful realization of the inflationary scenario, with very reasonable parameters values. The scalar electrodynamics inflationary scenario thus obtained are seen to be in good agreement with the most recent observational data.

  5. Renormalization-group improved inflationary scenarios

    Science.gov (United States)

    Pozdeeva, E. O.; Vernov, S. Yu.

    2017-03-01

    The possibility to construct an inflationary scenario for renormalization-group improved potentials corresponding to the Higgs sector of quantum field models is investigated. Taking into account quantum corrections to the renormalization-group potential which sums all leading logs of perturbation theory is essential for a successful realization of the inflationary scenario, with very reasonable parameters values. The scalar electrodynamics inflationary scenario thus obtained are seen to be in good agreement with the most recent observational data.

  6. Future mobile internet services : business model scenarios

    OpenAIRE

    2004-01-01

    In this report we explore future business models for mobile internet services. Based on four different scenarios, we sketch out how future conditions in the mobile industry may influence value propositions, value networks, and financial aspects of mobile services. The four scenarios vary along two dimensions - technological development and social identity, and different combinations of these two dimensions provide us with four scenarios where quite different business models can be expected. M...

  7. COMPETITIVE INTELLIGENCE ANALYSIS - SCENARIOS METHOD

    Directory of Open Access Journals (Sweden)

    Ivan Valeriu

    2014-07-01

    Full Text Available Keeping a company in the top performing players in the relevant market depends not only on its ability to develop continually, sustainably and balanced, to the standards set by the customer and competition, but also on the ability to protect its strategic information and to know in advance the strategic information of the competition. In addition, given that economic markets, regardless of their profile, enable interconnection not only among domestic companies, but also between domestic companies and foreign companies, the issue of economic competition moves from the national economies to the field of interest of regional and international economic organizations. The stakes for each economic player is to keep ahead of the competition and to be always prepared to face market challenges. Therefore, it needs to know as early as possible, how to react to others’ strategy in terms of research, production and sales. If a competitor is planning to produce more and cheaper, then it must be prepared to counteract quickly this movement. Competitive intelligence helps to evaluate the capabilities of competitors in the market, legally and ethically, and to develop response strategies. One of the main goals of the competitive intelligence is to acknowledge the role of early warning and prevention of surprises that could have a major impact on the market share, reputation, turnover and profitability in the medium and long term of a company. This paper presents some aspects of competitive intelligence, mainly in terms of information analysis and intelligence generation. Presentation is theoretical and addresses a structured method of information analysis - scenarios method – in a version that combines several types of analysis in order to reveal some interconnecting aspects of the factors governing the activity of a company.

  8. Modeling of Demining Scenarios Using Metal Detectors

    Directory of Open Access Journals (Sweden)

    John Fernando Vargas Buitrago

    2014-08-01

    Full Text Available This paper presents an analytical model and a numerical model that uses the finite element method to simulate demining scenarios using metal detectors. Using the analytical model, simulations of typical demining scenarios with varying parameters were executed. In addition, an analysis was made that aids in clearly understanding the effect of the scenario variables on a Continuous Wave metal detector response. In order to experimentally validate the numerical model, a Continuous Wave metal detector prototype was built to obtain experimental data. The numerical method can also be used to simulate demining scenarios with high metallic content landmines.

  9. Energy scenarios for Colombia: process and content

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Ricardo A. [National Univ. of Colombia, Escuela de Geosciencias y Medio Ambiente, Medellin (Colombia); Vesga, Daniel R.A. [Unidad de Planeacion Minero Energetica, Bogota (Colombia); Cadena, Angela I. [Los Andes Univ., School of Engineering, Bogota (Colombia); Boman, Ulf [Kairos Future AB, Stockholm (Sweden); Larsen, Erik [Cass Business School, London (United Kingdom); Dyner, Isaac [Universidad Nacional de Colombia, Energy Inst., Medellin (Colombia)

    2005-02-01

    This paper presents the approach undertaken, and the four energy scenarios that have been developed, to support long term energy policy in Colombia. The scenarios were constructed with emphasis on maximum interaction between stakeholders in the Colombian energy sector. The process directly involved over 120 people. The scenarios were developed as strategic support tools for the Energy and Mining Planning Unit (UPME), which is the Colombian institution in charge of developing the country's energy strategies and National Energy Policy. The methodology employed is presented, followed by a detailed description of each of the four scenarios. (Author)

  10. From Scenarios to Test Implementations Via Promela

    Science.gov (United States)

    Ulrich, Andreas; Alikacem, El-Hachemi; Hallal, Hesham H.; Boroday, Sergiy

    We report on a tool for generating executable concurrent tests from scenarios specified as message sequence charts. The proposed approach features three steps: 1) Deriving a MSC test implementation from a MSC scenario, 2) Mapping the test implementation into a Promela model, 3) Generating executable test scripts in Java. The generation of an intermediate Promela model allows for model-checking to inspect the test implementation for properties like soundness, fault detection power as well as for consistency checking between different test scenarios. Moreover decoupling the executable test scripts from the scenario specification makes it possible to use different backend code generators to support other scripting languages when needed.

  11. The unfolding: scenario planning in nursing.

    Science.gov (United States)

    Woude, Diana Vander; Damgaard, Gloria; Hegge, Margaret J; Soholt, Deb; Bunkers, Sandra Schmidt

    2003-01-01

    An interdisciplinary consortium organized a group to explore the meaning and the future of nursing in South Dakota using scenario planning. This column provides a general description of the four scenarios that emerged, some observations about how they might evolve, comments on their implications, and first-person stories, as told by fictitious residents. The process of scenario planning is connected to nursing science by explicating how five lessons of scenario planning are linked with Parse's human becoming concepts of creative imagining, glimpsing the paradoxical, and affirming personal becoming.

  12. Scenario research: Can the future be predicted?

    DEFF Research Database (Denmark)

    Stacey, Julia; Sonne, Anne-Mette

    2000-01-01

    whether the shopping situation described will become a reality, but attempts can be made to come up with qualified indications on possible development directions. In connection with a scenario research project, researchers from MAPP and the Danish Technological University have looked into the future...... possible futures. In the process of creating the scenarios, researchers at MAPP and the Danish Technical University formulated mini scenarios based on their research. The scenarios were used as inspiration in discussions with experts from industry, trade organisations, authorities etc. and later discussed...... and supplemented at workshops - one for each of the four sectors. Experts from industry, trade organisations, retailing, authorities and other interested parties participated....

  13. Uncertainty in Integrated Assessment Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Mort Webster

    2005-10-17

    trends from a model for uncertainty projections. The probability distributions of these critical model drivers, and the resulting uncertainty in projections from a range of models, can provide the basis of future emission scenario set designs.

  14. Scenario planning methodology in biomedicine sciences

    Directory of Open Access Journals (Sweden)

    Iraj Nabipour

    2015-07-01

    Full Text Available Scenario planning is a process that stimulates imaginative, creative thinking to better prepare an organization for the future. It is also as a tool to promote innovation activities in organizations. Scenario planning may provide alternate futures in which strategies of the organization develop. Very recently, Jay Ogilvy introduced an eight steps scenario planning and strategic forecasting. According to this eight-step process, scenario planning has two major parts: first, choosing which scenario logics to flesh out, a task that comprises the first five steps, and second, telling the actual story, its implications and early indicators, which compromise the remaining steps. In order to identify opportunities and challenges faced by biomedicine sciences there are continually increasing trends for scenario planning in the field. In highly uncertain environments, as are faced in biomedicine sciences, scenario planning can provide a robust, flexible path to navigate. By evaluating the implications of societal, economic and policy impacts of these scenarios, biosciences organizations can determine how to manage a transition to regenerative medicine and personalized medicine, both of which could disrupt current healthcare systems.

  15. Evaluation Framework for Dependable Mobile Learning Scenarios

    Science.gov (United States)

    Bensassi, Manel; Laroussi, Mona

    2014-01-01

    The goal of the dependability analysis is to predict inconsistencies and to reveal ambiguities and incompleteness in the designed learning scenario. Evaluation, in traditional learning design, is generally planned after the execution of the scenario. In mobile learning, this stage becomes too difficult and expensive to apply due to the complexity…

  16. Development of advanced inductive scenarios for ITER

    NARCIS (Netherlands)

    Luce, T. C.; Challis, C. D.; Ide, S.; Joffrin, E.; Kamada, Y.; Polizer, P. A.; Schweinzer, J.; Sips, A.C.C.; Stober, J.; Giruzzi, G.; Kessel, C. E.; Murakami, M.; Na, Y.-S.; Park, J. M.; Polevoi, A. R.; Budny, R. V.; Citrin, J.; Garcia, J.; Hayashi, N.; Hobirk, J.; Hudson, B. F.; Imbeaux, F.; Isayama, A.; McDonald, D. C.; Nakano, T.; Oyama, N.; Parail, V.V.; Petrie, T. W.; Petty, C. C.; Suzuki, T.; Wade, M. R.

    2014-01-01

    Since its inception in 2002, the International Tokamak Physics Activity topical group on Integrated Operational Scenarios (IOS) has coordinated experimental and modelling activity on the development of advanced inductive scenarios for applications in the ITER tokamak. The physics basis and the prosp

  17. Scenario Planning at College of Marin.

    Science.gov (United States)

    College of Marin, Kentfield, CA.

    This article reviews the scenario planning process implemented at the College of Marin (California). Scenario planning is a creative process in which a group of people who share a common fate develop stories about different ways their future might unfold, and use these stories to make decisions about what path to take. The Global Business Network…

  18. Molecular Diagnostic Analysis of Outbreak Scenarios

    Science.gov (United States)

    Morsink, M. C.; Dekter, H. E.; Dirks-Mulder, A.; van Leeuwen, W. B.

    2012-01-01

    In the current laboratory assignment, technical aspects of the polymerase chain reaction (PCR) are integrated in the context of six different bacterial outbreak scenarios. The "Enterobacterial Repetitive Intergenic Consensus Sequence" (ERIC) PCR was used to analyze different outbreak scenarios. First, groups of 2-4 students determined optimal…

  19. Scenario Planning at College of Marin.

    Science.gov (United States)

    College of Marin, Kentfield, CA.

    This article reviews the scenario planning process implemented at the College of Marin (California). Scenario planning is a creative process in which a group of people who share a common fate develop stories about different ways their future might unfold, and use these stories to make decisions about what path to take. The Global Business Network…

  20. Action research Toolkit II: The Scenario Workshop

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2003-01-01

    The article describes the scenario workshop within the action research paradigm. In addtion, the maina phases and the functions of the facilitator and the participants are outlined. Finally,it describes and analyses the experiences of using the scenario workshop in practice....

  1. EDITORIAL: Where next with global environmental scenarios? Where next with global environmental scenarios?

    Science.gov (United States)

    O'Neill, Brian; Pulver, Simone; Van Deveer, Stacy; Garb, Yaakov

    2008-12-01

    Scenarios have become a standard tool in the portfolio of techniques that scientists and policy-makers use to envision and plan for the future. Defined as plausible, challenging and relevant stories about how the future might unfold that integrate quantitative models with qualitative assessments of social and political trends, scenarios are a central component in assessment processes for a range of global issues, including climate change, biodiversity, agriculture, and energy. Yet, despite their prevalence, systematic analysis of scenarios is in its beginning stages. Fundamental questions remain about both the epistemology and scientific credibility of scenarios and their roles in policymaking and social change. Answers to these questions have the potential to determine the future of scenario analyses. Is scenario analysis moving in the direction of earth system governance informed by global scenarios generated through increasingly complex and comprehensive models integrating socio-economic and earth systems? Or will global environmental scenario analyses lose favour compared to more focused, policy-driven, regionally specific modelling? These questions come at an important time for the climate change issue, given that the scenario community, catalyzed by the Intergovernmental Panel on Climate Change (IPCC), is currently preparing to embark on a new round of scenario development processes aimed at coordinating research and assessment, and informing policy, over the next five to ten years. These and related questions about where next to go with global environmental scenarios animated a workshop held at Brown University (Note1) that brought together leading practitioners and scholars of global environmental change scenarios from research, policy-making, advocacy, and business settings. The workshop aimed to provide an overview of current practices/best practices in scenario production and scenario use across a range of global environmental change arenas. Participants

  2. Tank waste remediation system operational scenario

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.E.

    1995-05-01

    The Tank Waste Remediation System (TWRS) mission is to store, treat, and immobilize highly radioactive Hanford waste (current and future tank waste and the strontium and cesium capsules) in an environmentally sound, safe, and cost-effective manner (DOE 1993). This operational scenario is a description of the facilities that are necessary to remediate the Hanford Site tank wastes. The TWRS Program is developing technologies, conducting engineering analyses, and preparing for design and construction of facilities necessary to remediate the Hanford Site tank wastes. An Environmental Impact Statement (EIS) is being prepared to evaluate proposed actions of the TWRS. This operational scenario is only one of many plausible scenarios that would result from the completion of TWRS technology development, engineering analyses, design and construction activities and the TWRS EIS. This operational scenario will be updated as the development of the TWRS proceeds and will be used as a benchmark by which to evaluate alternative scenarios.

  3. Comparison of future energy scenarios for Denmark

    DEFF Research Database (Denmark)

    Kwon, Pil Seok; Østergaard, Poul Alberg

    2012-01-01

    Scenario-making is becoming an important tool in energy policy making and energy systems analyses. This article probes into the making of scenarios for Denmark by presenting a comparison of three future scenarios which narrate 100% renewable energy system for Denmark in 2050; IDA 2050, Climate...... Commission 2050, and CEESA (Coherent Energy and Environmental System Analysis). Generally, although with minor differences, the scenarios suggest the same technological solutions for the future such as expansion of biomass usage and wind power capacity, integration of transport sector into the other energy...... sectors. The methodologies used in two academic scenarios, IDA 2050 and CEESA, are compared. The main differences in the methodologies of IDA 2050 and CEESA are found in the estimation of future biomass potential, transport demand assessment, and a trial to examine future power grid in an electrical...

  4. Scenarios for Ecosystem Services: An Overview

    Directory of Open Access Journals (Sweden)

    Elena M. Bennett

    2006-06-01

    Full Text Available The Millennium Ecosystem Assessment (MA scenarios address changes in ecosystem services and their implications for human well-being. Ecological changes pose special challenges for long-term thinking, because of the possibility of regime shifts that occur rapidly yet alter the availability of ecosystem services for generations. Moreover, ecological feedbacks can intensify human modification of ecosystems, creating a spiral of poverty and ecosystem degradation. Such complex dynamics were evaluated by a mixture of qualitative and quantitative analyses in the MA scenarios. Collectively, the scenarios explore problems such as the connections of poverty reduction and ecosystem services, and trade-offs among ecosystem services. Several promising approaches are considered by the scenarios, including uses of biodiversity to build resilience of ecosystem services, actively adaptive management, and green technology. Although the scenarios do not prescribe an optimal path, they illuminate the consequences of different policies toward ecosystem services.

  5. Participatory Scenario Generation: Communicating Usability Issues in Product Design through User Involvement in Scenario Generation

    NARCIS (Netherlands)

    Bijl-Brouwer, van der Mieke; Voort, van der Mascha C.

    2009-01-01

    Scenarios have proven to be a valuable tool in evaluating and communicating usability issues in consumer product design. Scenarios are explicit descriptions of hypothetical use situations. Realistic scenarios can serve as a valuable frame of reference to evaluate design solutions with regard to usab

  6. Participatory Scenario Generation: Communicating Usability Issues in Product Design through User Involvement in Scenario Generation

    NARCIS (Netherlands)

    van der Bijl-Brouwer, Mieke; van der Voort, Mascha C.

    2009-01-01

    Scenarios have proven to be a valuable tool in evaluating and communicating usability issues in consumer product design. Scenarios are explicit descriptions of hypothetical use situations. Realistic scenarios can serve as a valuable frame of reference to evaluate design solutions with regard to usab

  7. Scenario Archetypes: Converging Rather than Diverging Themes

    Directory of Open Access Journals (Sweden)

    Jon P. Sadler

    2012-04-01

    Full Text Available Future scenarios provide challenging, plausible and relevant stories about how the future could unfold. Urban Futures (UF research has identified a substantial set (>450 of seemingly disparate scenarios published over the period 1997–2011 and within this research, a sub-set of >160 scenarios has been identified (and categorized based on their narratives according to the structure first proposed by the Global Scenario Group (GSG in 1997; three world types (Business as Usual, Barbarization, and Great Transitions and six scenarios, two for each world type (Policy Reform—PR, Market Forces—MF, Breakdown—B, Fortress World—FW, Eco-Communalism—EC and New Sustainability Paradigm—NSP. It is suggested that four of these scenario archetypes (MF, PR, NSP and FW are sufficiently distinct to facilitate active stakeholder engagement in futures thinking. Moreover they are accompanied by a well-established, internally consistent set of narratives that provide a deeper understanding of the key fundamental drivers (e.g., STEEP—Social, Technological, Economic, Environmental and Political that could bring about realistic world changes through a push or a pull effect. This is testament to the original concept of the GSG scenarios and their development and refinement over a 16 year period.

  8. Metaphorical scenarios in business science discourse

    Directory of Open Access Journals (Sweden)

    Baramee Kheovichai

    2015-04-01

    Full Text Available Metaphor has been shown to play an important role in business science discourse. Yet, previous corpus-based studies only investigated a pre-selected list of metaphoric expressions, potentially rendering the analysis incomplete. Furthermore, some studies which only focused on lexis did not analyse how the lexical items may construct business concepts in terms of scenarios. The purpose of this research is to investigate metaphor used to construct business concepts in business research articles. 42 business research articles published in 2009-2010 from five journals ranked in the top-ten according to the 2007 journal impact factors (Thompson Reuters, 2008 constitute the data of this study. Semantic annotation software USAS (Rayson, 2008 was used to assist in the retrieval of metaphoric expressions. Furthermore, manual analysis of concordances was done to find metaphorical expressions that had not been captured by the semantic tags. The analysis of these metaphoric expressions was based on Conceptual Metaphor Theory (Lakoff & Johnson, 1980 and Metaphor Scenario (Musolff, 2006. Data analysis indicates that metaphor constructs business concepts as scenarios which have participants performing actions to reach their goal according to the SOURCE-PATH-GOAL schema of the source domains. At the centre of these scenarios, the BOUNDED SPACE source domain serves as a conceptual space or a setting for each scenario. Other source domains, which are WAR, SPORT, GAME, JOURNEY, MACHINE, LIVING ORGANISM, BUILDING and PHYSICAL FORCES, project the scenarios onto the space, forming interconnected and coherent scenarios of business discourse

  9. Trust and the illusive force of scenarios

    DEFF Research Database (Denmark)

    Selin, Cynthia Lea

    2006-01-01

    Scenarios are typically defined as stories describing different but equally plausible futures that are developed using methods that systematically gather perceptions about certainties and uncertainties. Scenarios are not intended to be truthful, but rather provocative and helpful in strategy...... frameworks for action. Trust speaks to persuasion and how stories of the future become trustworthy and garner credibility when traditional measures are fundamentally insufficient and irrelevant. That is, if we take as an assumption that we are not transpiring for truth or truthfulness in scenarios, then what...

  10. Cluster correlations - a test for biased scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-gonzalez, E.; Sanz, J.L.

    1988-01-01

    The cluster autocorrelation function Xi(c) and the galaxy-cluster cross-correlation Xi(gc) are used to test the biased structure formation in several scenarios. A scale-free spectrum can reproduce the observed Xi(c), but it is in contradiction to Xi(gc). On the other hand, acceptable results are obtained for Xi(gc) in cold dark matter scenarios with adiabatic and isocurvature fluctuations. However, these scenarios are rejected on the grounds of Xi(c). 42 references.

  11. Fish Springs pond snail : Refuge communication scenario

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Communication scenario between the branch of Listing and Recovery, Fish and Wildlife Enhancement, and Fish Springs National Wildlife Refuge (NWR), in regards to the...

  12. Experts dismiss doomsday scenarios for RHIC

    CERN Document Server

    Levi, B G

    2000-01-01

    A panel of particle physicists examining the possibility that operation of RHIC could generate blackholes or 'strangelets' which would consume ordinary matter, have declared that such scenarios are 'firmly excluded' (1 p).

  13. Type Ia supernovae and the DD scenario

    CERN Document Server

    Isern, J; Lorén-Aguilar, P

    2011-01-01

    Type Ia supernovae are thought to be the outcome of the thermonuclear explosion of a white dwarf in a close binary system. Two possible scenarios, not necessarily incompatible, have been advanced. One assumes a white dwarf that accretes matter from a nondegenerate companion (the single degenerate scenario), the other assumes two white dwarfs that merge as a consequence of the emission of gravitational waves (the double degenerate scenario). The delay time distribution of star formation bursts strongly suggests that the DD scenario should be responsible of the late time explosions, but this contradicts the common wisdom that the outcome of the merging of two white dwarfs is an accretion induced collapse to a neutron star. In this contribution we review some of the most controversial issues of this problem.

  14. Swift Development of Immersive Learning Scenarios

    NARCIS (Netherlands)

    Nadolski, Rob; Kurvers, Hub

    2010-01-01

    Nadolski, R. J., & Kurvers, H. J. (2010, 23 March). Swift Development of Immersive Learning Scenarios. Presentation during a workshop with Sector5, Heerlen, The Netherlands: Open University of the Netherlands; iCoper.

  15. Management strategies in hospitals: scenario planning

    National Research Council Canada - National Science Library

    Ghanem, Mohamed; Schnoor, Jörg; Heyde, Christoph-Eckhard; Kuwatsch, Sandra; Bohn, Marco; Josten, Christoph

    2015-01-01

    .... This work highlights the importance of scenario planning in hospitals, proposes an elaborated definition of the stakeholders of a hospital and defines the influence factors to which hospitals are exposed to. Methodology...

  16. Management strategies in hospitals: scenario planning

    National Research Council Canada - National Science Library

    Ghanem, Mohamed; Schnoor, Jörg; Heyde, Christoph-Eckhard; Kuwatsch, Sandra; Bohn, Marco; Josten, Christoph

    2015-01-01

    .... This work highlights the importance of scenario planning in hospitals, proposes an elaborated definition of the stakeholders of a hospital and defines the influence factors to which hospitals are exposed...

  17. Peninsular Florida future scenarios integrated project

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a integrated scenario project to the Florida state line that incorporates updated critical land and water identification project layers with a decision...

  18. Group 1: Scenario design and development issues

    Science.gov (United States)

    Sherwin, P.

    1981-01-01

    All LOFT scenarios and flight segments should be designed on the basis of a detailed statement of specific objectives. These objectives must state what kind of situation is to be addressed and why. The origin, routing, and destination of a particular scenario should be dictated by the specific objectives for that scenario or leg. Other factors to be considered are the desired weather, climate, etc. Simulator visual system, as well as other capabilities and limitations must be considered at a very early stage of scenario design. The simulator navigation area must be apropriate and must coincide with current Jeppeson charts. Much of the realism of LOFT is destroyed if the crew is unable to use current manuals and other materials.

  19. Scenarios for the food industry in 2010

    DEFF Research Database (Denmark)

    Harmsen, Hanne; Jensen, Birger Boutrup; Sonne, Anne-Mette

    2001-01-01

    Predicting the future is impossible; corporate decision-makers have, however, to decide which competencies to develop precisely on this basis. This article presents the results of a research project on scenario analyses in the Danish food industry. The aim of the study is to look at alternative...... visions of the future of the food industry and to assess their implications for competence requirements. Given the uncertain nature of the environment, food companies cannot rely on today's competencies being sufficient to fulfil the demands of tomorrow's markets. However, predicting the determinants...... of success in the food industry 10 years hence is a daunting task. Scenario techniques can be very useful in this respect (von Reibnitz, 1988). The contribution of the article is the methodological approach to scenario building, which combines academic and industry input and translates the scenarios...

  20. Subsistence Exposure Scenarios for Tribal Applications.

    Science.gov (United States)

    Harper, Barbara; Harding, Anna; Harris, Stuart; Berger, Patricia

    2012-07-01

    The article provides an overview of methods that can be used to develop exposure scenarios for unique tribal natural resource usage patterns. Exposure scenarios are used to evaluate the degree of environmental contact experienced by people with different patterns of lifestyle activities, such as residence, recreation, or work. in 1994, U.S. President Bill Clinton's Executive Order 12898 recognized that disproportionately high exposures could be incurred by people with traditional subsistence lifestyles because of their more intensive contact with natural resources. Since then, we have developed several tribal exposure scenarios that reflect tribal-specific traditional lifeways. These scenarios are not necessarily intended to capture contemporary resource patterns, but to describe how the resources were used before contamination or degradation, and will be used once again in fully traditional ways after cleanup and restoration. The direct exposure factors for inhalation and soil ingestion rates are the same in each tribal scenario, but the diets are unique to each tribe and its local ecology, natural foods, and traditional practices. Scenarios, in part or in whole, also have other applications, such as developing environmental standards, evaluating disproportionate exposures, developing sampling plans, planning for climate change, or evaluating service flows as part of natural resource damage assessments.

  1. Analysis of the energy scenario Negawatt 2006; Analyse du scenario energetique negaWatt 2006

    Energy Technology Data Exchange (ETDEWEB)

    Acket, C.; Bacher, P

    2006-10-15

    The association Negawatt published in 2003 an energy scenario for the France in 2050, under the name of Negawatt 2006. This document aims to analyze the scenario Negawatt with a comparison of the scenario published on the web site of SLC, Save the Climate. The authors analyzes the main three sectors: electricity, transports and residential to propose their comparison in conclusion. (A.L.B.)

  2. Water use implications of biofuel scenarios

    Science.gov (United States)

    Teter, J.; Mishra, G. S.; Yeh, S.

    2012-12-01

    Existing studies rely upon attributional lifecycle analysis (LCA) approaches to estimate water intensity of biofuels in liters of irrigated/evapotranspiration water consumed for biofuel production. Such approaches can be misleading. From a policy perspective, a better approach is to compare differential water impacts among scenarios on a landscape scale. We address the shortcomings of existing studies by using consequential LCA, and incorporate direct and indirect land use (changes) of biofuel scenarios, marginal vs. average biofuel water use estimates, future climate, and geographic heterogeneity. We use the outputs of a partial equilibrium economic model, climate and soil data, and a process-based crop-soil-climate-water model to estimate differences in green water (GW - directly from precipitation to soil) and blue water (BW - supplied by irrigation) use among three scenarios: (1) business-as-usual (BAU), (2) Renewable Fuels Standard (RFS) mandates, and (3) a national Low Carbon Fuel Standard (LCFS) plus the RFS scenario. We use spatial statistical methods to interpolate key climatic variables using daily climate observations for the contiguous USA. Finally, we use FAO's crop model AquaCrop to estimate the domestic GW and BW impacts of biofuel policies from 2007-2035. We assess the differences among scenarios along the following metrics: (1) crop area expansion at the county level, including prime and marginal lands, (2) crop-specific and overall annual/seasonal water balances including (a) water inflows (irrigation & precipitation), (b) crop-atmosphere interactions: (evaporation & transpiration) and (d) soil-water flows (runoff & soil infiltration), in mm 3 /acre over the relevant time period. The functional unit of analysis is the BW and GW requirements of biofuels (mm3 per Btu biofuel) at the county level. Differential water use impacts among scenarios are a primarily a function of (1) land use conversion, in particular that of formerly uncropped land classes

  3. USGS Multi-Hazards Winter Storm Scenario

    Science.gov (United States)

    Cox, D. A.; Jones, L. M.; Perry, S. C.

    2008-12-01

    The USGS began an inter-disciplinary effort, the Multi Hazards Demonstration Project (MHDP), in 2007 to demonstrate how hazards science can improve a community's resiliency to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages the user community in setting research goals and directs efforts towards research products that can be applied to loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. It detailed the realistic outcomes of a hypothetical, but plausible, magnitude 7.8 earthquake on the San Andreas Fault in southern California. Over 300 scientist and experts contributed to designing the earthquake and understanding the impacts of such a disaster, including the geotechnical, engineering, social, cultural, environmental, and economic consequences. The scenario advanced scientific understanding and exposed numerous vulnerabilities related to emergency response and lifeline continuity management. The ShakeOut Scenario was the centerpiece of the Nation's largest-ever emergency response exercise in November 2008, dubbed "The Great Southern California ShakeOut" (www.shakeout.org). USGS Multi-Hazards is now preparing for its next major public project, a Winter Storm Scenario. Like the earthquake scenario, experts will be brought together to examine in detail the possibility, cost and consequences of a winter storm disaster including floods, landslides, coastal erosion and inundation; debris flows; biologic consequences like extirpation of endangered species; physical damages like bridge scour, road closures, dam failure, property loss, and water system collapse. Consideration will be given to the vulnerabilities associated with a catastrophic disruption to the water supply to southern California; the resulting impacts on ground water pumping, seawater intrusion, water supply degradation, and land subsidence; and a

  4. Development of nonproliferation and assessment scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Finley, Melissa; Barnett, Natalie Beth

    2005-10-01

    The overall objective of the Nonproliferation and Assessments Scenario Development project is to create and analyze potential and plausible scenarios that would lead to an adversary's ability to acquire and use a biological weapon. The initial three months of funding was intended to be used to develop a scenario to demonstrate the efficacy of this analysis methodology; however, it was determined that a substantial amount of preliminary data collection would be needed before a proof of concept scenario could be developed. We have dedicated substantial effort to determine the acquisition pathways for Foot and Mouth Disease Virus, and similar processes will be applied to all pathogens of interest. We have developed a biosecurity assessments database to capture information on adversary skill locales, available skill sets in specific regions, pathogen sources and regulations involved in pathogen acquisition from legitimate facilities. FY06 funding, once released, will be dedicated to data collection on acquisition, production and dissemination requirements on a pathogen basis. Once pathogen data has been collected, scenarios will be developed and scored.

  5. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-10-01

    Full Text Available This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050 scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow, aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO2 emissions (~42 000 gigagrams by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  6. RESGen: Renewable Energy Scenario Generation Platform

    DEFF Research Database (Denmark)

    Iversen, Jan Emil Banning; Pinson, Pierre

    2016-01-01

    Space-time scenarios of renewable power generation are increasingly used as input to decision-making in operational problems. They may also be used in planning studies to account for the inherent uncertainty in operations. Similarly using scenarios to derive chance-constraints or robust...... optimization sets for corresponding optimization problems is useful in a power system context. Generating and evaluating such spacetime scenarios is difficult. While quite a number of proposals have appeared in the literature, a gap between methodological proposals and actual usage in operational and planning...... studies remains. Consequently, our aim here is to propose an open-source platform for space-time probabilistic forecasting of renewable energy generation (wind and solar power). This document covers both methodological and implementation aspects, to be seen as a companion document for the open...

  7. Scenario research: The food industry in 2010

    DEFF Research Database (Denmark)

    Stacey, Julia; Sonne, Anne-Mette; Jensen, Birger Boutrup

    2001-01-01

    have accepted both functional foods and genetically modified foods. They have confidence in modern food production and believe they are well informed and have a realistic picture of how to produce modern foods. The last scenario 'Tight spending' is based on a lower disposable income and extensive......What kind of foods will the consumers choose to buy in 2010? Will they be buying organic foods, functional foods or go for the cheapest products? Nobody can predict the future. However, by using scenario techniques qualified indications on future developments can be put together. Researchers...... at MAPP and the Department of Manufacturing Engineering and Management, The Technical University of Denmark have constructed three scenarios about the Danish food industry in 2010. The aim has been to identify the demands the food industry can expect to meet in the future plus which research areas...

  8. Selecting Supersymmetric String Scenarios From Sparticle Spectra

    CERN Document Server

    Allanach, Benjamin C; Quevedo, Fernando

    2002-01-01

    We approach the following question: if supersymmetry is discovered, how can we select among different supersymmetric extensions of the Standard Model? In particular, we perform an analysis of the sparticle spectrum in low-energy string effective theories, asking which observables best distinguish various scenarios. We examine scenarios differing by the fundamental string scale and concentrate on GUT and intermediate scale models. We scan over all parameters (two goldstino angles, tan beta and the gravitino mass) in each scenario, finding ratios of sparticle masses that provide the maximum discrimination between them. The necessary accuracy for discrimination is determined in each case. We find that the required accuracy on various sparticle mass ratios is at the few percent level, a precision that may be achieved in future linear colliders. We place phenomenological constraints on the parameter space and determine the supersymmetric contribution to the muon anomalous magnetic moment.

  9. Generating Scenarios When Data Are Missing

    Science.gov (United States)

    Mackey, Ryan

    2007-01-01

    The Hypothetical Scenario Generator (HSG) is being developed in conjunction with other components of artificial-intelligence systems for automated diagnosis and prognosis of faults in spacecraft, aircraft, and other complex engineering systems. The HSG accepts, as input, possibly incomplete data on the current state of a system (see figure). The HSG models a potential fault scenario as an ordered disjunctive tree of conjunctive consequences, wherein the ordering is based upon the likelihood that a particular conjunctive path will be taken for the given set of inputs. The computation of likelihood is based partly on a numerical ranking of the degree of completeness of data with respect to satisfaction of the antecedent conditions of prognostic rules. The results from the HSG are then used by a model-based artificial- intelligence subsystem to predict realistic scenarios and states.

  10. Scenario Development for Sustainable Food Consumption

    DEFF Research Database (Denmark)

    Reisch, Lucia; Farsang, Andrea; Jégou, Francois

    in seasonal dependency due to global trade and storage and process technology. On the demand side, relatively high and stable incomes combined with low food prices have in-creased accessibility, availability and affordability of a highly diverse food supply. Yet, according to the FAO, total food production...... events and uncertainties, especially on long-term horizons such as 25-50 years ahead. In order to deal with these uncertainties, complexities and long-term challenges as well as to influence developments pro-actively, scenario planning is increasingly applied in both policy making and knowledge brokerage....... Scenarios can reveal uncertainties, can help prepare for unexpected changes and highlight crucial decisions to be taken today. Scenarios can offer a clearer picture of the present and visions for the future, can help to identify key driving forces and their trends as well as as-sess potential outcomes...

  11. Environmental evaluation of plastic waste management scenarios

    DEFF Research Database (Denmark)

    Rigamonti, L.; Grosso, M.; Møller, Jacob

    2014-01-01

    The management of the plastic fraction is one of the most debated issues in the discussion on integrated municipal solid waste systems. Both material and energy recovery can be performed on such a waste stream, and different separate collection schemes can be implemented. The aim of the paper...... is to contribute to the debate, based on the analysis of different plastic waste recovery routes. Five scenarios were defined and modelled with a life cycle assessment approach using the EASEWASTE model. In the baseline scenario (P0) the plastic is treated as residual waste and routed partly to incineration...... with energy recovery and partly to mechanical biological treatment. A range of potential improvements in plastic management is introduced in the other four scenarios (P1–P4). P1 includes a source separation of clean plastic fractions for material recycling, whereas P2 a source separation of mixed plastic...

  12. Market structure scenarios in international steam coal

    Energy Technology Data Exchange (ETDEWEB)

    Trueby, Johannes; Paulus, Moritz

    2011-04-15

    The seaborne steam coal market changed in recent years. Trade volumes grew dynamically, important players emerged and since 2007 prices increased significantly and remained relatively high since then. In this paper we analyse market equilibria in the years 2006 and 2008 by testing for two possible market structure scenarios in this market: perfect competition and an oligopoly setup with major exporters competing in quantities. We conclude from our results that international steam coal trade is not perfectly competitive as there is a large spread between marginal costs and prices and a low capacity utilisation in 2008. Further, trade flows are generally more diversified in reality than in the competitive scenario. However, also the Cournot scenarios fail to accurately explain real market outcomes. We conclude that only more sophisticated models of strategic behaviour can predict market equilibria in international steam coal trade. (orig.)

  13. xLPR Scenario Analysis Report.

    Energy Technology Data Exchange (ETDEWEB)

    Eckert-Gallup, Aubrey Celia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lewis, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Nevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hund, Lauren [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Clark, Andrew Jordan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mariner, Paul [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    This report describes the methods, results, and conclusions of the analysis of 11 scenarios defined to exercise various options available in the xLPR (Extremely Low Probability of Rupture) Version 2 .0 code. The scope of the scenario analysis is three - fold: (i) exercise the various options and components comprising xLPR v2.0 and defining each scenario; (ii) develop and exercise methods for analyzing and interpreting xLPR v2.0 outputs ; and (iii) exercise the various sampling options available in xLPR v2.0. The simulation workflow template developed during the course of this effort helps to form a basis for the application of the xLPR code to problems with similar inputs and probabilistic requirements and address in a systematic manner the three points covered by the scope.

  14. Scenarios for the making of vertebrates.

    Science.gov (United States)

    Holland, Nicholas D; Holland, Linda Z; Holland, Peter W H

    2015-04-23

    Over the past 200 years, almost every invertebrate phylum has been proposed as a starting point for evolving vertebrates. Most of these scenarios are outdated, but several are still seriously considered. The short-range transition from ancestral invertebrate chordates (similar to amphioxus and tunicates) to vertebrates is well accepted. However, longer-range transitions leading up to the invertebrate chordates themselves are more controversial. Opinion is divided between the annelid and the enteropneust scenarios, predicting, respectively, a complex or a simple ancestor for bilaterian animals. Deciding between these ideas will be facilitated by further comparative studies of multicellular animals, including enigmatic taxa such as xenacoelomorphs.

  15. 500 GeV ILC Operating Scenarios

    CERN Document Server

    Brau, James E; Barklow, T; Brau, J; Fujii, K; Gao, J; List, J; Walker, N; Yokoya, K

    2015-01-01

    The ILC Technical Design Report documents the design of a 500 GeV linear collider, but does not specify the center-of-mass energy steps of operation for the collider. The ILC Parameters Joint Working Group has studied possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes, and considered the evolution of the physics outcomes. These physics goals include Higgs precision measurements, top quark measurements and searches for new physics. We present an "optimized" operating scenario and the anticipated evolution of the precision of the ILC measurements.

  16. Sensitivity analysis on fuel scenario associated magnitudes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Martinez, M.; Alvarez-Velarde, F.

    2014-07-01

    Nuclear fuel cycle scenario analyses are needed as a support for policy makers in terms of sustainability, fuel diversity, security of supply, and social and environmental effects. These analyses are usually aimed to the study of the impact of certain hypotheses on some fuel cycle indicators, without considering the uncertainties on those hypotheses. The expert group of the NEA/OECD on Advanced Fuel Cycle Scenarios, where this work is framed, is devoted to fill this gap, laying the foundations for deep analysis of the sensibilities on fuel cycle indicators. (Author)

  17. Computational Scenario-based Capability Planning

    CERN Document Server

    Abbass, Hussein; Dam, Helen; Baker, Stephen; Whitacre, James M; Sarker, Ruhul; 10.1145/1389095.1389378

    2009-01-01

    Scenarios are pen-pictures of plausible futures, used for strategic planning. The aim of this investigation is to expand the horizon of scenario-based planning through computational models that are able to aid the analyst in the planning process. The investigation builds upon the advances of Information and Communication Technology (ICT) to create a novel, flexible and customizable computational capability-based planning methodology that is practical and theoretically sound. We will show how evolutionary computation, in particular evolutionary multi-objective optimization, can play a central role - both as an optimizer and as a source for innovation.

  18. Using Service Scenarios to Model Business Services

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    The purpose of the paper is to present and evaluate the notion of service scenarios. A service is work done by a service executor in interaction with a service consumer. A service scenario is a model of a service system and the roles that are played by the actors participating and interacting dur...... of a case study in a public library. The case study indicates that service systems should be understood as socio-technical systems in which service executors and service consumers co-create value in mutual interaction with each other and with a set of shared resources....

  19. Scenario-based table top simulations

    DEFF Research Database (Denmark)

    Broberg, Ole; Edwards, Kasper; Nielsen, J.

    2012-01-01

    This study developed and tested a scenario-based table top simulation method in a user-driven innovation setting. A team of researchers worked together with a user group of five medical staff members from the existing clinic. Table top simulations of a new clinic were carried out in a simple model...... including patient scenarios, LEGO figures, shoeboxes, and cardboard. The results indicated that table top simulations is a simple, cheap and powerful tool to generate and test innovative conceptual solutions in the early stages of a design process....

  20. Maximising the Effectiveness of a Scenario Planning Process: Tips for Scenario Planners in Higher Education

    Science.gov (United States)

    Sayers, Nicola

    2011-01-01

    Scenario planning is a tool which can help organisations and people to think about, and plan for, the long-term future. In basic terms, it involves creating a number of in-depth scenarios (stories), each of which tells of a different possible future for an organisation or issue, and considering how each different future might influence…

  1. Maximising the Effectiveness of a Scenario Planning Process: Tips for Scenario Planners in Higher Education

    Science.gov (United States)

    Sayers, Nicola

    2011-01-01

    Scenario planning is a tool which can help organisations and people to think about, and plan for, the long-term future. In basic terms, it involves creating a number of in-depth scenarios (stories), each of which tells of a different possible future for an organisation or issue, and considering how each different future might influence…

  2. Negatep: A Scenario for Combating Global Warming; Le scenario Negatep. Un scenario de lutte contre le rechauffement climatique

    Energy Technology Data Exchange (ETDEWEB)

    Acket, C.; Bacher, P. [Sauvons Le Climat, 92 - Boulogne Billancourt (France)

    2011-07-15

    There have been an increasing number of foresight exercises in the field of energy and global warming in recent years, as we have seen from the articles devoted to these questions by Futuribles in 2011 (both in this special issue and in the April number). It is certainly the case that the goals for greenhouse-gas emission reduction are rather ambitious, particularly in France, it being the aim of the 2005 French framework law on energy to reduce carbon gas discharges by a factor of four. Among these scenarios, the Negatep scenario developed by Claude Acket and Pierre Bacher from the 'Sauvons le climat' [Let's save the climate] Association proposes to achieve this ('factor 4') goal in France by 2050 by reducing fossil fuel use by 75% and replacing this as quickly as possible with electricity produced from non-carbon-gas-emitting sources - chiefly, nuclear power and renewables. The authors lay out their goals here, backed up by figures, comparing these with the reference scenario. They also show the path that must be followed to arrive at these goals, particularly in the residential and tertiary sectors, and in transport and industry (through control of needs and recourse to alternative energy sources). They close by comparing the Negatep scenario with two other more recent scenarios aimed also at reducing greenhouse gas emissions, on the one hand in Europe, and on the other in Germany. The comparison confirms that they were right to rely on electricity as a substitute for oil, but gives them cause for concern in respect of the consequences (formidable in their view) that the replacement of nuclear power and coal energy by intermittent renewable energies might have in Europe, both with regard to costs and to the effects on the power network. (authors)

  3. When Things Do Not Go as Expected: Scenario Life Savers

    DEFF Research Database (Denmark)

    Dieckmann, Peter; Lippert, A.; Glavin, R.;

    2010-01-01

    In this paper we discuss scenario life savers - interventions before and during simulation scenarios that allow to create and use relevant learning opportunities, even if unexpected events happen during the conduction of the scenario. Scenario life savers are needed, when the comprehension...... or acceptance of the scenario by the participants is at stake, thus compromising learning opportunities. Scenario life savers can principally work by bringing participants back on track of the planned scenario or by adapting the conduction to their actions on the fly. Interventions can be within the logic...... of the scenario or from the "outside," not being part of the scenario itself. Scenario life savers should be anticipated during the design of scenarios and used carefully during their conduction, aiming to maximize the learning for participants. (Sim Healthcare 5: 219-225, 2010)...

  4. Maize leaf development under climate change scenarios

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2010-11-01

    Full Text Available The objective of this work was to simulate maize leaf development in climate change scenarios at Santa Maria, RS, Brazil, considering symmetric and asymmetric increases in air temperature. The model of Wang & Engel for leaf appearance rate (LAR, with genotype-specific coefficients for the maize variety BRS Missões, was used to simulate tip and expanded leaf accumulated number from emergence to flag leaf appearance and expansion, for nine emergence dates from August 15 to April 15. LAR model was run for each emergence date in 100-year climate scenarios: current climate, and +1, +2, +3, +4 and +5°C increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum air temperature. Maize crop failure due to frost decreased in elevated temperature scenarios, in the very early and very late emergence dates, indicating a lengthening in the maize growing season in warmer climates. The leaf development period in maize was shorter in elevated temperature scenarios, with greater shortening in asymmetric temperature increases, indicating that warmer nights accelerate vegetative development in maize.

  5. No-arbitrage bounds for financial scenarios

    DEFF Research Database (Denmark)

    Geyer, Alois; Hanke, Michael; Weissensteiner, Alex

    2014-01-01

    We derive no-arbitrage bounds for expected excess returns to generate scenarios used in financial applications. The bounds allow to distinguish three regions: one where arbitrage opportunities will never exist, a second where arbitrage may be present, and a third, where arbitrage opportunities...

  6. The Future of Food: Scenarios for 2050

    NARCIS (Netherlands)

    Hubert, B.; Rosegrant, M.; Boekel, van M.A.J.S.; Ortiz, R.

    2010-01-01

    This background article addresses key challenges of adequately feeding a population of 9 billion by 2050, while preserving the agro-ecosystems from which other services are also expected. One of the scenario-buildings uses the Agrimonde platform, which considers the following steps: choosing the sce

  7. NIDI scenario. Strong population decline in China

    OpenAIRE

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario projects less population growth in Nigeria and sharp population decline in China.

  8. NIDI scenario. Strong population decline in China

    NARCIS (Netherlands)

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario

  9. Scenarios and design: Scoping the dialogue space

    DEFF Research Database (Denmark)

    Selin, Cynthia Lea; Kimbell, Lucy; Ramirez, Rafael

    2015-01-01

    This paper examines the intersections between two futures-oriented domains of practice and research: scenario planning and design. Both are practice-led, with uneasy but productive relationships with theorizing. Exploring their relations offers ways to address challenges faced by interdisciplinar...

  10. Scenario-based Training: Director's Cut

    NARCIS (Netherlands)

    Peeters, M.M.M.; Van den Bosch, K.; Meyer, J-J.Ch.; Neerincx, M.A.

    2011-01-01

    Research regarding autonomous learning shows that freeplay does not result in optimal learning. Combining scenario-based training with intelligent agent technology off ers the possibility to create autonomous training enriched with automated adaptive support delivered by a director agent. We conduct

  11. Scenario simulation of water security in China

    Institute of Scientific and Technical Information of China (English)

    OUYANG Zhi-yun; ZHAO Tong-qian; WANG Ru-song; Leif S(O)RLUND; ZHANG Qiao-xian

    2004-01-01

    Limited water resources, increasing demand, low use efficiency, and serious pollution result in severe water resource difficult in China. The evaluation of addressing water problems and the search for effective countermeasures that ensure sustainable water use are key to China's sustainable development. The "compound water security" consists of food security, life security, environmental security, and economic security. By establishing a conceptual model, the water security of China has been simulated in terms of four scenarios called BAU(the business-as-usual scenario), TEC(the technology and economics scenario), IVL(the institution, values, and lifestyles scenario) and TSD(toward sustainable development) in this paper. The results indicated that water crises, especially water shortages, are being experienced now and will continue to do so for a relatively long time in China and that it is possible to reach a basic balance between supply and demand of water and grain under the TSD developing pattern by a series of approaches including technological innovation, policy adjustments, and behaviour inducement.

  12. National FCEV and Hydrogen Fueling Station Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian; Melaina, Marc

    2016-06-09

    This presentation provides a summary of the FY16 activities and accomplishments for NREL's national fuel cell electric vehicle (FCEV) and hydrogen fueling station scenarios project. It was presented at the U.S. Department of Energy Hydrogen and Fuel Cells Program 2016 Annual Merit Review and Peer Evaluation Meeting on June 9, 2016, in Washington, D.C.

  13. Scenarios as methods of Community Building

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2002-01-01

    The significance of the scenario workshop is the combination of creativity, reflection and action helping the participants to imaging and realise desirable futures. It can contribute to fill the gaps between visions of the future and the present situation, giving the participants knowledge and po...

  14. European Water Footprint Scenarios for 2050

    Directory of Open Access Journals (Sweden)

    A. Ertug Ercin

    2016-05-01

    Full Text Available This study develops water footprint scenarios for Europe for 2050, at the country level, based on projections regarding population and economic growth, production and trade patterns, consumption patterns (diets and bioenergy use and technological development. The objective is to estimate possible future changes in the green, blue and grey water footprint (WF of production and consumption, to analyze the main drivers of projected changes and to assess Europe’s future dependence on water resources elsewhere in the world. We develop four scenarios, considering globalization versus regional self-sufficiency, and development driven by economic objectives versus development driven by social and environmental objectives. The study shows that the most critical driver of change affecting Europe’s future WF is the consumption pattern. The WFs of both production and consumption in Western Europe increase under scenarios with high meat consumption and decrease with low-meat scenarios. Besides, additional water demands from increasing biofuel needs will put further pressure on European water resources. The European countries with a large ratio of external to total WF of consumption in 2000 decrease their dependencies on foreign water resources in 2050.

  15. Forlic deliverable 5.1: Persona scenarios

    NARCIS (Netherlands)

    Gijsbers, Govert; Leendertse, Matthijs; Leis, Miriam; Kirschner, Paul A.; Hoogveld, Bert; Stoyanov, Slavi; Weber, Mark

    2015-01-01

    This document describes nine persona scenarios. The outcomes of a group concept mapping (GCM) exercise were used as input to create nine personas. The basic data for each persona contains demographic information, its position in a three by three persona matrix, and an overview of the relevant clust

  16. Orchestrating Learning Scenarios for the Borderless Classroom

    NARCIS (Netherlands)

    Tan, Esther; Rusman, Ellen

    2016-01-01

    This part of the symposium focuses on the design of seamless learning experiences in a borderless classroom. There are two parts to this symposium. We start with unpacking various theoretical approaches that inform the instructional design of boundary-crossing learning scenarios, such as social lear

  17. Beyond Data: The World of Scenario Planning.

    Science.gov (United States)

    Goens, George A.

    2001-01-01

    Leadership involves more than analyzing data and making decisions. Even the most strategically made plans can be circumvented by people or unanticipated events. Scenario planning allows administrators to weave various components (driving forces, predetermined elements, and critical uncertainties) into plausible stories of what futures can unfold.…

  18. Experiments, Passive Observation and Scenario Analysis

    DEFF Research Database (Denmark)

    Hoover, Kevin D.; Juselius, Katarina

    that he develops in his famous monograph, The Probability Approach in Econometrics (1944). We show how, once the details of the analogy are systematically understood, the experimental analogy can be used to shed light on theory-consistent cointegrated vector autoregression (CVAR) scenario analysis. CVAR...

  19. Cell Load Balancing in Heterogeneous Scenarios

    DEFF Research Database (Denmark)

    Eduardo, Simao; Rodrigues, Antonio; Mihovska, Albena D.

    2013-01-01

    Cell load imbalances in wireless networks degrade performance. Macro and small cell collocated deployments (heterogeneous scenario) constitutes a new problem for load balancing. This paper proposes a novel admission control algorithm for an optimal solution to the assignment of traffic flows...

  20. Linguistic evaluation of terrorist scenarios: example application.

    Energy Technology Data Exchange (ETDEWEB)

    Darby, John L.

    2007-03-01

    In 2005, a group of international decision makers developed a manual process for evaluating terrorist scenarios. That process has been implemented in the approximate reasoning Java software tool, LinguisticBelief, released in FY2007. One purpose of this report is to show the flexibility of the LinguisticBelief tool to automate a custom model developed by others. LinguisticBelief evaluates combinations of linguistic variables using an approximate reasoning rule base. Each variable is comprised of fuzzy sets, and a rule base describes the reasoning on combinations of variables fuzzy sets. Uncertainty is considered and propagated through the rule base using the belief/plausibility measure. This report documents the evaluation and rank-ordering of several example terrorist scenarios for the existing process implemented in our software. LinguisticBelief captures and propagates uncertainty and allows easy development of an expanded, more detailed evaluation, neither of which is feasible using a manual evaluation process. In conclusion, the Linguistic-Belief tool is able to (1) automate an expert-generated reasoning process for the evaluation of the risk of terrorist scenarios, including uncertainty, and (2) quickly evaluate and rank-order scenarios of concern using that process.

  1. Demografische modellen voor scenario-onderzoek

    NARCIS (Netherlands)

    Hoogenveen RT

    1991-01-01

    A demographic model is described that has been used in scenario-research for calculating future population numbers. The demographic model developed is a discrete Markov-model. It calculates the changes in the Netherlands population numbers for each year successively. the model is specially develo

  2. Solution space diagram in conflict detection scenarios

    NARCIS (Netherlands)

    Rahman, S.M.A.; Borst, C.; Mulder, M.; Van Paassen, M.M.

    2015-01-01

    This research investigates the use of Solution Space Diagram (SSD) as a measure of sector complexity and also as a predictor of performance and workload, focusing on the scenarios regarding Air Traffic Controller (ATCO)’s ability to detect future conflicts. A human-in-the-loop experiment with varyin

  3. Transport Technologies and Policy Scenarios to 2050

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-10-15

    As part of the major WEC study on Scenarios to 2050, a specific investigation was undertaken on measures required in the transport sector to secure sustainable energy and sustainable mobility in the future. This report outlines the results conducted by a study group of international WEC transport experts and gives concrete policy recommendations to develop sustainable transport systems.

  4. Orchestrating Learning Scenarios for the Borderless Classroom

    NARCIS (Netherlands)

    Tan, Esther; Rusman, Ellen

    2016-01-01

    This part of the symposium focuses on the design of seamless learning experiences in a borderless classroom. There are two parts to this symposium. We start with unpacking various theoretical approaches that inform the instructional design of boundary-crossing learning scenarios, such as social

  5. Use of simplifier scenarios for CRM training

    Science.gov (United States)

    Weatherly, D.

    1984-01-01

    Cockpit resource management (CRM) at Metro Airlines is discussed. The process by which the program of CRM training was initiated is mentioned. Management aspects of various flying scenarios are considered. The transfer of training from the classroom to the field is assessed.

  6. CIVILIZATION SCENARIOS OF DEVELOPMENT OF RUSSIA

    Directory of Open Access Journals (Sweden)

    A. N. Kharin

    2013-01-01

    Full Text Available In the modern world plays an important role civilization factor. In this connection beforeRussiaa task stands forming of civilization identity. A problem consists in that, that exists a few scenarios of civilization development. To their consideration and this article is devoted.

  7. Flooding Capability for River-based Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Curtis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steven [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ryan, Emerald [Idaho State Univ., Pocatello, ID (United States); Calhoun, Donna [Boise State Univ., ID (United States); Sampath, Ramprasad [Centroid Labs., Los Angeles, CA (United States); Anderson, S. Danielle [Idaho National Lab. (INL), Idaho Falls, ID (United States); Casteneda, Cody [Boise State Univ., ID (United States)

    2015-10-01

    This report describes the initial investigation into modeling and simulation tools for application of riverine flooding representation as part of the Risk-Informed Safety Margin Characterization (RISMC) Pathway external hazards evaluations. The report provides examples of different flooding conditions and scenarios that could impact river and watershed systems. Both 2D and 3D modeling approaches are described.

  8. Orchestrating Learning Scenarios for the Borderless Classroom

    NARCIS (Netherlands)

    Tan, Esther; Rusman, Ellen

    2016-01-01

    This part of the symposium focuses on the design of seamless learning experiences in a borderless classroom. There are two parts to this symposium. We start with unpacking various theoretical approaches that inform the instructional design of boundary-crossing learning scenarios, such as social lear

  9. Wiki Based Collaborative Learning in Interuniversity Scenarios

    Science.gov (United States)

    Katzlinger, Elisabeth; Herzog, Michael A.

    2014-01-01

    In business education advanced collaboration skills and media literacy are important for surviving in a globalized business where virtual communication between enterprises is part of the day-by-day business. To transform these global working situations into higher education, a learning scenario between two universities in Germany and Austria was…

  10. The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

    Science.gov (United States)

    O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; Eyring, Veronika; Friedlingstein, Pierre; Hurtt, George; Knutti, Reto; Kriegler, Elmar; Lamarque, Jean-Francois; Lowe, Jason; Meehl, Gerald A.; Moss, Richard; Riahi, Keywan; Sanderson, Benjamin M.

    2016-09-01

    Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially explicit

  11. The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

    Energy Technology Data Exchange (ETDEWEB)

    O& amp; apos; Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; Eyring, Veronika; Friedlingstein, Pierre; Hurtt, George; Knutti, Reto; Kriegler, Elmar; Lamarque, Jean-Francois; Lowe, Jason; Meehl, Gerald A.; Moss, Richard; Riahi, Keywan; Sanderson, Benjamin M.

    2016-01-01

    Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially

  12. When Things Do Not Go as Expected: Scenario Life Savers

    DEFF Research Database (Denmark)

    Dieckmann, Peter; Lippert, A.; Glavin, R.;

    2010-01-01

    In this paper we discuss scenario life savers - interventions before and during simulation scenarios that allow to create and use relevant learning opportunities, even if unexpected events happen during the conduction of the scenario. Scenario life savers are needed, when the comprehension or acc...

  13. Curvaton scenarios with inflaton decays into curvatons

    CERN Document Server

    Byrnes, Christian T; Liddle, Andrew R

    2016-01-01

    We consider the possible decay of the inflaton into curvaton particles during reheating and analyse its effect on curvaton scenarios. Typical decay curvatons are initially relativistic then become non-relativistic, and change the background history of the Universe. We show that this change to the background is the only way in which observational predictions of the scenario are modified. Moreover, once the required amplitude of perturbations is fixed by observation there are no signatures of such decays in other cosmological observables. The decay curvatons can prevent the Universe from becoming dominated by the curvaton condensate, making it impossible to match observations in parts of parameter space. This constrains the branching ratio of the inflaton to curvaton to be less than of order $0.1$ typically. If the branching ratio is below about $10^{-4}$ it has negligible impact on the model parameter space and can be ignored.

  14. The hexagon hypothesis: Six disruptive scenarios.

    Science.gov (United States)

    Burtles, Jim

    2015-01-01

    This paper aims to bring a simple but effective and comprehensive approach to the development, delivery and monitoring of business continuity solutions. To ensure that the arguments and principles apply across the board, the paper sticks to basic underlying concepts rather than sophisticated interpretations. First, the paper explores what exactly people are defending themselves against. Secondly, the paper looks at how defences should be set up. Disruptive events tend to unfold in phases, each of which invites a particular style of protection, ranging from risk management through to business continuity to insurance cover. Their impact upon any business operation will fall into one of six basic scenarios. The hexagon hypothesis suggests that everyone should be prepared to deal with each of these six disruptive scenarios and it provides them with a useful benchmark for business continuity.

  15. Occupational health scenario of Indian informal sector.

    Science.gov (United States)

    Nag, Anjali; Vyas, Heer; Nag, Pranab

    2016-08-05

    Workers in the Indian informal sector are engaged with different occupations. These occupations involve varied work related hazards. These occupational hazards are a consequent risk to health. The study aimed to determine occupational health scenario in the Indian Informal sector. One thousand eleven hundred twenty two workers from five different occupations namely weaving (handloom and power loom), construction, transportation, tobacco processing and fish processing were assessed by interviewer administered health questionnaire. Workers suffered from musculo-skeletal complaints, respiratory health hazards, eye problems and skin related complaints. There was a high prevalence of self-reported occupational health problems in the selected sectors. The study finds that workers have occupational exposures to multiple hazards. The absence of protective guards aggrevate their health condition. The study attempts to draws an immediate attention on the existing health scenario of the Indian Informal sector.

  16. Rolling in the modulated reheating scenario

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Naoya [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario, M5S 3H4 (Canada); Kobayashi, Takeshi; Erickcek, Adrienne L., E-mail: nkobayas@cita.utoronto.ca, E-mail: takeshi@cita.utoronto.ca, E-mail: erickcek@physics.unc.edu [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, Ontario, M5S 3H8 (Canada)

    2014-01-01

    In the modulated reheating scenario, the field that drives inflation has a spatially varying decay rate, and the resulting inhomogeneous reheating process generates adiabatic perturbations. We examine the statistical properties of the density perturbations generated in this scenario. Unlike earlier analyses, we include the dynamics of the field that determines the inflaton decay rate. We show that the dynamics of this modulus field can significantly alter the amplitude of the power spectrum and the bispectrum, even if the modulus field has a simple potential and its effective mass is smaller than the Hubble rate. In some cases, the evolution of the modulus amplifies the non-Gaussianity of the perturbations to levels that are excluded by recent observations of the cosmic microwave background. Therefore, a proper treatment of the modulus dynamics is required to accurately calculate the statistical properties of the perturbations generated by modulated reheating.

  17. Rolling in the Modulated Reheating Scenario

    CERN Document Server

    Kobayashi, Naoya; Erickcek, Adrienne L

    2014-01-01

    In the modulated reheated scenario, the field that drives inflation has a spatially varying decay rate, and the resulting inhomogeneous reheating process generates adiabatic perturbations. We examine the statistical properties of the density perturbations generated in this scenario. Unlike earlier analyses, we include the dynamics of the field that determines the inflaton decay rate. We show that the dynamics of this modulus field can significantly alter the amplitude of the power spectrum and the bispectrum, even if the modulus field has a simple potential and its effective mass is smaller than the Hubble rate. In some cases, the evolution of the modulus amplifies the non-Gaussianity of the perturbations to levels that are excluded by recent observations of the cosmic microwave background. Therefore, a proper treatment of the modulus dynamics is required to accurately calculate the statistical properties of the perturbations generated by modulated reheating.

  18. TECHNOLOGICAL SCENARIOS TO THE DEMAND FOR SUGARCANE

    Directory of Open Access Journals (Sweden)

    Ana Paula Franco Paes Leme Barbosa

    2012-06-01

    Full Text Available From the first decade of the 2000s, it is clear that there is an increase in discussions involving sustainability, including the bioenergy issue, to which Brazil has drawn the attention due to advances in the ethanol industry. Advances in engine technology reflected new opportunities for this industry and, according to the Ten-Year Energy Plan for 2019 developed by the Ministry of Mines and Energy, there is an expected increase in demand for ethanol of 90% by 2019 (Brazil, 2010. However, new technologies for the conversion and use of sugarcane and the complex context of this industry add uncertainties to this sector. Aiming to discuss and include the uncertainties on the agenda of this industry, this study proposes to elaborate and discuss prospective scenarios to the demand for sugarcane. Four scenarios with different perspectives of technological advance and market development were elaborated and discussed in the conclusion.

  19. Selecting reasonable future land use scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Allred, W.E.; Smith, R.W. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-12-31

    This paper examines a process to help select the most reasonable future land use scenarios for hazardous waste and/or low-level radioactive waste disposal sites. The process involves evaluating future land use scenarios by applying selected criteria currently used by commercial mortgage companies to determine the feasibility of obtaining a loan for purchasing such land. The basis for the process is that only land use activities for which a loan can be obtained will be considered. To examine the process, a low-level radioactive waste site, the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory, is used as an example. The authors suggest that the process is a very precise, comprehensive, and systematic (common sense) approach for determining reasonable future use of land. Implementing such a process will help enhance the planning, decisionmaking, safe management, and cleanup of present and future disposal facilities.

  20. Clinical research monitoring: scenarios and challenges

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Sierra Romero

    2013-01-01

    Full Text Available Clinical research is essential for the development of new drugs, diagnostic tests and new devices. Clinical monitoring is implemented to improve the quality of research and attain high ethical and scientific standards. This review discusses the role of clinical monitors, taking into account the variety of scenarios in which medical research is developed, and highlights the challenges faced by research teams to ensure that patients rights are respected and that the social role of scientific research is preserved. Specific emphasis is given to the ethical dilemmas related to the multiple roles which clinical monitors play in the research framework, mainly those involving the delicate equilibrium between the loyalty to the sponsor and to the research subjects. The essential role of clinical monitoring for research developed in poor healthcare scenarios is highlighted as an approach to get the local infrastructure strengthening needed to achieve an adequate level of good clinical practices.

  1. Scenario Development for Sustainable Food Consumption

    DEFF Research Database (Denmark)

    Reisch, Lucia; Farsang, Andrea; Jégou, Francois

    in general as well as in the context of the CORPUS project. Moreover, it reviews recent examples of scenario building approaches in the sustainable food domain. The potential roles and applications of different types of scenarios such as backcasting or quantitative models and their benefit for policy making......Over the last few decades, considerable changes in food consumption – such as eating habits, dietary changes, availability and accessability of food – have taken place. These are mainly due to an increase in productivity of the food sector, a greater diversity in product choices and a decrease...... in seasonal dependency due to global trade and storage and process technology. On the demand side, relatively high and stable incomes combined with low food prices have in-creased accessibility, availability and affordability of a highly diverse food supply. Yet, according to the FAO, total food production...

  2. Scenario Crisis Cases in Distance Learning Sessions

    Science.gov (United States)

    Antunes, A.

    2013-04-01

    We discuss early results using student-lead role-play of crises and disaster scenarios to encourage engagement in distance learning sessions. The disadvantage of distance learning via web interface—the lack of face-to-face and the ease with which a student can remain quiet—is balanced by the wealth of Internet-accessible media reports of past mission disasters. Capitol College minimizes the lecture component to simply frame each session's open-ended crisis in our Mission Operations engineering course. The students are presented with a historical ‘disaster’ but not its resolution; they present their course of action, then the lecturer steps in to debrief. With a wealth of past cases available on the web, use of scenarios rather than lectures shows early signs of being viable model for encouraging discussion and interaction within distance learning for a variety of course topics.

  3. LCA Modeling of Waste Management Scenarios

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Simion, F.; Tonini, Davide

    2011-01-01

    and shows that recycling is superior to incineration with energy recovery, which again is better than landfilling. Cleary (2010) reviewed 20 waste management scenarios assessed in 11 studies published in the period 2002–2008 and concluded that, due to lack of transparency regarding boundary conditions...... and exchange with the energy systems, a comparison of results was hampered on a system level. In addition, differences in waste composition may affect the LCA results. This chapter provides results of LCA modeling of 40 waste management scenarios handling the same municipal waste (MSW) and using different...... management systems. The study focuses on Europe in terms of waste composition and exchange with the energy system. The waste management systems modeled are described with respect to waste composition, waste management technologies, mass flows and energy exchange in the systems. Results are first presented...

  4. Land-Use Scenarios: National-Scale Housing-Density Scenarios Consistent with Climate Change Storylines (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Land-Use Scenarios: National-Scale Housing-Density Scenarios Consistent with Climate Change Storylines. This report describes the scenarios and models used to generate national-scale housing density scenarios for the con...

  5. Motivating an intergenerational workforce: scenarios for success.

    Science.gov (United States)

    Wieck, K Lynn

    2007-01-01

    Although much has been written about the challenge of having four generations in the workplace simultaneously, problems of conflict, misunderstanding, and divisiveness continue. This article provides a snapshot of each generation as context. A series of scenarios based on Maslow's Hierarchy of Needs are then presented with insights into how each generation might approach the situation, along with hints for successfully managing toward positive outcomes. The expected outcome is a technique for each generation to look at workplace situations from all perspectives.

  6. Visualization in sporting contexts : the team scenario

    OpenAIRE

    Kazmi, Aqeel H.; O'Grady, Michael J; O'Hare, G. M. P. (Greg M. P.)

    2011-01-01

    Wearable sensor systems require an interactive and communicative interface for the user to interpret data in a meaningful way. The development of adaptive personalization features in a visualization tool for such systems can convey a more meaningful picture to the user of the system. In this paper, a visualization tool called Visualization in Team Scenarios (VTS), which can be used by a coach to monitor an athlete’s physiological parameters, is presented. The VTS has been implemented with a w...

  7. Energy Scenarios For A Sustainable Future

    Directory of Open Access Journals (Sweden)

    Ion Chiuta

    2008-05-01

    Full Text Available It is clear that the future is not simplysomething already predetermined that we must acceptblindly: rather, it is open and to a large extent determinedby the course of actions we decide to take. For thisreason, we need to look at the future and its uncertaintiesin an articulated fashion, developing specific tools toconsider both how the future might unfold if we do notact and how we might like the future to unfold if actionwere to be taken.As demonstrated on valuable intellectual exercise forlooking into an uncertain future involves the developmentof “scenarios” intended as logical and plausibleconjectures about how fundamental drivers will affectglobal societies, economics, resource use and theenvironment. The literature review shows a multiplicity ofscenarios, conducted as different scales ranging from thenational to the global scale, with different time horizonsand with a focus on different strategic issues.Exploratory scenarios help prepare for events that,without representing a straight-line continuation of pasttrends, are plausible and entirely possible. Exploratoryscenarios can help a lot to accelerate and calibrate theresponse to new developments, as well as providing astrategic framework technology development policy.Normative scenario has, as its goal, the evolution of adesirable future rather than a future inexorably imposedupon us by the inertia of system. Building a normativescenario requires the creators to clearly define thedesirable characteristics of their future, and to expressthis future in terms of measurable targets.The use of such a scenario process lies as much in theissues it requires us to comfort as the precise details isgenerates. The future will not look exactly like the oneenvisioned: other priorities will intercede and nationalconditions and circumstances will dictate the specifics ofthe energy policies that may be adopted. But such aprocess of interacting around scenarios can providevaluable guidance as to

  8. Arctic shipping emissions inventories and future scenarios

    Directory of Open Access Journals (Sweden)

    J. J. Corbett

    2010-04-01

    Full Text Available The Arctic is a sensitive region in terms of climate change and a rich natural resource for global economic activity. Arctic shipping is an important contributor to the region's anthropogenic air emissions, including black carbon – a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow. These emissions are projected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. To understand the impacts of these increased emissions, scientists and modelers require high-resolution, geospatial emissions inventories that can be used for regional assessment modeling. This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050 scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. Short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing; a first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase climate forcing due to Arctic ships by at least 17% compared to warming from these vessels' CO2 emissions (~42 000 gigagrams. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships.

  9. Conditional Reasoning: Scenario or context effects

    OpenAIRE

    Valiña, Mª Dolores; Seoane, Gloria; Ghering, Sonnya; Ferraces, Mª José; Fernández-Rey, Xosé

    1992-01-01

    This paper study the importance of contextual factors in reasoning with conditional inference tasks. In this experiment subjects were given conditional sentences in the context of narrative texts, Short stories about scenarios of the daily life were described in this texts. The experiment manipulated: a) context (causal or promises/threats), b) degree of factual relation between antecedent and consequent of conditional (deterministic, probabilistic or without relation), c) congruence betwe...

  10. CORSICA modelling of ITER hybrid operation scenarios

    Science.gov (United States)

    Kim, S. H.; Bulmer, R. H.; Campbell, D. J.; Casper, T. A.; LoDestro, L. L.; Meyer, W. H.; Pearlstein, L. D.; Snipes, J. A.

    2016-12-01

    The hybrid operating mode observed in several tokamaks is characterized by further enhancement over the high plasma confinement (H-mode) associated with reduced magneto-hydro-dynamic (MHD) instabilities linked to a stationary flat safety factor (q ) profile in the core region. The proposed ITER hybrid operation is currently aiming at operating for a long burn duration (>1000 s) with a moderate fusion power multiplication factor, Q , of at least 5. This paper presents candidate ITER hybrid operation scenarios developed using a free-boundary transport modelling code, CORSICA, taking all relevant physics and engineering constraints into account. The ITER hybrid operation scenarios have been developed by tailoring the 15 MA baseline ITER inductive H-mode scenario. Accessible operation conditions for ITER hybrid operation and achievable range of plasma parameters have been investigated considering uncertainties on the plasma confinement and transport. ITER operation capability for avoiding the poloidal field coil current, field and force limits has been examined by applying different current ramp rates, flat-top plasma currents and densities, and pre-magnetization of the poloidal field coils. Various combinations of heating and current drive (H&CD) schemes have been applied to study several physics issues, such as the plasma current density profile tailoring, enhancement of the plasma energy confinement and fusion power generation. A parameterized edge pedestal model based on EPED1 added to the CORSICA code has been applied to hybrid operation scenarios. Finally, fully self-consistent free-boundary transport simulations have been performed to provide information on the poloidal field coil voltage demands and to study the controllability with the ITER controllers. Extended from Proc. 24th Int. Conf. on Fusion Energy (San Diego, 2012) IT/P1-13.

  11. New procedure of generation of action scenarios

    Science.gov (United States)

    Staniszewski, Michał; Wereszczyński, Kamil; Michalczuk, Agnieszka; Fernes, Daniel; Segen, Jakub; Kulbacki, Marek; Wojciechowski, Konrad

    2017-07-01

    Algorithms of tracking and action recognition are still under development and many problems still have to be solved. New methods are usually tested on available benchmarks with defined actions and human behavior however such approach has many limitations. For that reason the authors proposed new procedure of generating random action instances using on graph-based scenarios. Such idea can be applied in creation of different datasets as well as in simulations.

  12. The development of climatic scenarios for Finland

    Energy Technology Data Exchange (ETDEWEB)

    Carter, T.; Tuomenvirta, H. [Finnish Meteorological Inst., Helsinki (Finland); Posch, M. [National Inst. of Public Health and the Environment, Bilthoven (Netherlands)

    1996-12-31

    One of the main objectives of the Finnish Research Programme on Climate Change (SILMU) has been to assess the possible impacts of future changes in climate due to the enhanced greenhouse effect on natural systems and human activities in Finland. In order to address this objective, it was first necessary to specify the types of climate changes to be expected in the Finnish region. Estimates of future climate are conventionally obtained using numerical models, which simulate the evolution of the future climate in response to radiative forcing due to changes in the composition of the atmosphere (i.e. of greenhouse gases and aerosols). However, there are large uncertainties in the model estimates because current knowledge and understanding of atmospheric processes remains incomplete. Since accurate predictions of climate change are not available, an alternative approach is to develop scenarios. These are plausible projections which reflect the best estimates to the future conditions but at the same time embrace the likely uncertainties attached to these estimates. In order to obtain expert opinion on the most appropriate methods of providing scenarios for SILMU, an International Workshop was organised in 1993. The recommendations of the Workshop formed the basis of the present project, initiated in 1994, to develop standard climatic scenarios for Finland

  13. Glacial CO2 Cycles: A Composite Scenario

    Science.gov (United States)

    Broecker, W. S.

    2015-12-01

    There are three main contributors to the glacial drawdown of atmospheric CO2 content: starvation of the supply of carbon to the ocean-atmosphere reservoir, excess CO2 storage in the deep sea, and surface-ocean cooling. In this talk, I explore a scenario in which all three play significant roles. Key to this scenario is the assumption that deep ocean storage is related to the extent of nutrient stratification of the deep Atlantic. The stronger this stratification, the larger the storage of respiration CO2. Further, it is my contention that the link between Milankovitch insolation cycles and climate is reorganizations of the ocean's thermohaline circulation leading to changes in the deep ocean's CO2 storage. If this is the case, the deep Atlantic d13C record kept in benthic foraminifera shells tells us that deep ocean CO2 storage follows Northern Hemisphere summer insolation cycles and thus lacks the downward ramp so prominent in the records of sea level, benthic 18O and CO2. Rather, the ramp is created by the damping of planetary CO2 emissions during glacial time intervals. As it is premature to present a specific scenario, I provide an example as to how these three contributors might be combined. As their magnitudes and shapes remain largely unconstrained, the intent of this exercise is to provoke creative thinking.

  14. Management strategies in hospitals: scenario planning

    Directory of Open Access Journals (Sweden)

    Ghanem, Mohamed

    2015-06-01

    Full Text Available Background: Instead of waiting for challenges to confront hospital management, doctors and managers should act in advance to optimize and sustain value-based health. This work highlights the importance of scenario planning in hospitals, proposes an elaborated definition of the stakeholders of a hospital and defines the influence factors to which hospitals are exposed to. Methodology: Based on literature analysis as well as on personal interviews with stakeholders we propose an elaborated definition of stakeholders and designed a questionnaire that integrated the following influence factors, which have relevant impact on hospital management: political/legal, economic, social, technological and environmental forces. These influence factors are examined to develop the so-called critical uncertainties. Thorough identification of uncertainties was based on a “Stakeholder Feedback”. Results: Two key uncertainties were identified and considered in this study: According to the developed scenarios, complementary education of the medical staff as well as of non-medical top executives and managers of hospitals was the recommended core strategy. Complementary scenario-specific strategic options should be considered whenever needed to optimize dealing with a specific future development of the health care environment. Conclusion: Strategic planning in hospitals is essential to ensure sustainable success. It considers multiple situations and integrates internal and external insights and perspectives in addition to identifying weak signals and “blind spots”. This flows into a sound planning for multiple strategic options. It is a state of the art tool that allows dealing with the increasing challenges facing hospital management.

  15. Clinical Scenarios for Discordant Anti-Xa

    Science.gov (United States)

    Vera-Aguilera, Jesus; Yousef, Hindi; Beltran-Melgarejo, Diego; Teng, Teng Hugh; Jan, Ramos; Mok, Mary; Vera-Aguilera, Carlos; Moreno-Aguilera, Eduardo

    2016-01-01

    Anti-Xa test measures the activity of heparin against the activity of activated coagulation factor X; significant variability of anti-Xa levels in common clinical scenarios has been observed. Objective. To review the most common clinical settings in which anti-Xa results can be bias. Evidence Review. Guidelines and current literature search: we used PubMed, Medline, Embase, and MEDION, from 2000 to October 2013. Results. Anti-Xa test is widely used; however the assay underestimates heparin concentration in the presence of significant AT deficiency, pregnancy, end stage renal disease, and postthrombolysis and in patients with hyperbilirubinemia; limited published data evaluating the safety and effectiveness of anti-Xa assays for managing UH therapy is available. Conclusions and Relevance. To our knowledge this is the first paper that summarizes the most common causes in which this assay can be affected, several “day to day” clinical scenarios can modify the outcomes, and we concur that these rarely recognized scenarios can be affected by negative outcomes in the daily practice. PMID:27293440

  16. Clinical Scenarios for Discordant Anti-Xa

    Directory of Open Access Journals (Sweden)

    Jesus Vera-Aguilera

    2016-01-01

    Full Text Available Anti-Xa test measures the activity of heparin against the activity of activated coagulation factor X; significant variability of anti-Xa levels in common clinical scenarios has been observed. Objective. To review the most common clinical settings in which anti-Xa results can be bias. Evidence Review. Guidelines and current literature search: we used PubMed, Medline, Embase, and MEDION, from 2000 to October 2013. Results. Anti-Xa test is widely used; however the assay underestimates heparin concentration in the presence of significant AT deficiency, pregnancy, end stage renal disease, and postthrombolysis and in patients with hyperbilirubinemia; limited published data evaluating the safety and effectiveness of anti-Xa assays for managing UH therapy is available. Conclusions and Relevance. To our knowledge this is the first paper that summarizes the most common causes in which this assay can be affected, several “day to day” clinical scenarios can modify the outcomes, and we concur that these rarely recognized scenarios can be affected by negative outcomes in the daily practice.

  17. Deforestation scenarios for the Bolivian lowlands.

    Science.gov (United States)

    Tejada, Graciela; Dalla-Nora, Eloi; Cordoba, Diana; Lafortezza, Raffaele; Ovando, Alex; Assis, Talita; Aguiar, Ana Paula

    2016-01-01

    Tropical forests in South America play a key role in the provision of ecosystem services such as carbon sinks, biodiversity conservation, and global climate regulation. In previous decades, Bolivian forests have mainly been deforested by the expansion of agricultural frontier development, driven by the growing demands for beef and other productions. In the mid-2000s the Movimiento al Socialismo (MAS) party rose to power in Bolivia with the promise of promoting an alternative development model that would respect the environment. The party passed the world's first laws granting rights to the environment, which they termed Mother Earth (Law No. 300 of 2012), and proposed an innovative framework that was expected to develop radical new conservation policies. The MAS conservationist discourse, policies, and productive practices, however, have since been in permanent tension. The government continues to guarantee food production through neo-extractivist methods by promoting the notion to expand agriculture from 3 to 13 million ha, risking the tropical forests and their ecosystem services. These actions raise major environmental and social concerns, as the potential impacts of such interventions are still unknown. The objective of this study is to explore an innovative land use modeling approach to simulate how the growing demand for land could affect future deforestation trends in Bolivia. We use the LuccME framework to create a spatially-explicit land cover change model and run it under three different deforestation scenarios, spanning from the present-2050. In the Sustainability scenario, deforestation reaches 17,703,786 ha, notably in previously deforested or degraded areas, while leaving forest extensions intact. In the Middle of the road scenario, deforestation and degradation move toward new or paved roads spreading across 25,698,327 ha in 2050, while intact forests are located in Protected Areas (PAs). In the Fragmentation scenario, deforestation expands to almost

  18. The HayWired earthquake scenario

    Science.gov (United States)

    Detweiler, Shane T.; Wein, Anne M.

    2017-04-24

    ForewordThe 1906 Great San Francisco earthquake (magnitude 7.8) and the 1989 Loma Prieta earthquake (magnitude 6.9) each motivated residents of the San Francisco Bay region to build countermeasures to earthquakes into the fabric of the region. Since Loma Prieta, bay-region communities, governments, and utilities have invested tens of billions of dollars in seismic upgrades and retrofits and replacements of older buildings and infrastructure. Innovation and state-of-the-art engineering, informed by science, including novel seismic-hazard assessments, have been applied to the challenge of increasing seismic resilience throughout the bay region. However, as long as people live and work in seismically vulnerable buildings or rely on seismically vulnerable transportation and utilities, more work remains to be done.With that in mind, the U.S. Geological Survey (USGS) and its partners developed the HayWired scenario as a tool to enable further actions that can change the outcome when the next major earthquake strikes. By illuminating the likely impacts to the present-day built environment, well-constructed scenarios can and have spurred officials and citizens to take steps that change the outcomes the scenario describes, whether used to guide more realistic response and recovery exercises or to launch mitigation measures that will reduce future risk.The HayWired scenario is the latest in a series of like-minded efforts to bring a special focus onto the impacts that could occur when the Hayward Fault again ruptures through the east side of the San Francisco Bay region as it last did in 1868. Cities in the east bay along the Richmond, Oakland, and Fremont corridor would be hit hardest by earthquake ground shaking, surface fault rupture, aftershocks, and fault afterslip, but the impacts would reach throughout the bay region and far beyond. The HayWired scenario name reflects our increased reliance on the Internet and telecommunications and also alludes to the

  19. Management strategies in hospitals: scenario planning.

    Science.gov (United States)

    Ghanem, Mohamed; Schnoor, Jörg; Heyde, Christoph-Eckhard; Kuwatsch, Sandra; Bohn, Marco; Josten, Christoph

    2015-01-01

    Instead of waiting for challenges to confront hospital management, doctors and managers should act in advance to optimize and sustain value-based health. This work highlights the importance of scenario planning in hospitals, proposes an elaborated definition of the stakeholders of a hospital and defines the influence factors to which hospitals are exposed to. Based on literature analysis as well as on personal interviews with stakeholders we propose an elaborated definition of stakeholders and designed a questionnaire that integrated the following influence factors, which have relevant impact on hospital management: political/legal, economic, social, technological and environmental forces. These influence factors are examined to develop the so-called critical uncertainties. Thorough identification of uncertainties was based on a "Stakeholder Feedback". Two key uncertainties were identified and considered in this study: the development of workload for the medical staff the profit oriented performance of the medical staff. According to the developed scenarios, complementary education of the medical staff as well as of non-medical top executives and managers of hospitals was the recommended core strategy. Complementary scenario-specific strategic options should be considered whenever needed to optimize dealing with a specific future development of the health care environment. Strategic planning in hospitals is essential to ensure sustainable success. It considers multiple situations and integrates internal and external insights and perspectives in addition to identifying weak signals and "blind spots". This flows into a sound planning for multiple strategic options. It is a state of the art tool that allows dealing with the increasing challenges facing hospital management.

  20. Management strategies in hospitals: scenario planning

    Science.gov (United States)

    Ghanem, Mohamed; Schnoor, Jörg; Heyde, Christoph-Eckhard; Kuwatsch, Sandra; Bohn, Marco; Josten, Christoph

    2015-01-01

    Background: Instead of waiting for challenges to confront hospital management, doctors and managers should act in advance to optimize and sustain value-based health. This work highlights the importance of scenario planning in hospitals, proposes an elaborated definition of the stakeholders of a hospital and defines the influence factors to which hospitals are exposed to. Methodology: Based on literature analysis as well as on personal interviews with stakeholders we propose an elaborated definition of stakeholders and designed a questionnaire that integrated the following influence factors, which have relevant impact on hospital management: political/legal, economic, social, technological and environmental forces. These influence factors are examined to develop the so-called critical uncertainties. Thorough identification of uncertainties was based on a “Stakeholder Feedback”. Results: Two key uncertainties were identified and considered in this study: the development of workload for the medical staff the profit oriented performance of the medical staff. According to the developed scenarios, complementary education of the medical staff as well as of non-medical top executives and managers of hospitals was the recommended core strategy. Complementary scenario-specific strategic options should be considered whenever needed to optimize dealing with a specific future development of the health care environment. Conclusion: Strategic planning in hospitals is essential to ensure sustainable success. It considers multiple situations and integrates internal and external insights and perspectives in addition to identifying weak signals and “blind spots”. This flows into a sound planning for multiple strategic options. It is a state of the art tool that allows dealing with the increasing challenges facing hospital management. PMID:26504735

  1. Underground infrastructure damage for a Chicago scenario

    Energy Technology Data Exchange (ETDEWEB)

    Dey, Thomas N [Los Alamos National Laboratory; Bos, Rabdall J [Los Alamos National Laboratory

    2011-01-25

    Estimating effects due to an urban IND (improvised nuclear device) on underground structures and underground utilities is a challenging task. Nuclear effects tests performed at the Nevada Test Site (NTS) during the era of nuclear weapons testing provides much information on how underground military structures respond. Transferring this knowledge to answer questions about the urban civilian environment is needed to help plan responses to IND scenarios. Explosions just above the ground surface can only couple a small fraction of the blast energy into an underground shock. The various forms of nuclear radiation have limited penetration into the ground. While the shock transmitted into the ground carries only a small fraction of the blast energy, peak stresses are generally higher and peak ground displacement is lower than in the air blast. While underground military structures are often designed to resist stresses substantially higher than due to the overlying rocks and soils (overburden), civilian structures such as subways and tunnels would generally only need to resist overburden conditions with a suitable safety factor. Just as we expect the buildings themselves to channel and shield air blast above ground, basements and other underground openings as well as changes of geology will channel and shield the underground shock wave. While a weaker shock is expected in an urban environment, small displacements on very close-by faults, and more likely, soils being displaced past building foundations where utility lines enter could readily damaged or disable these services. Immediately near an explosion, the blast can 'liquefy' a saturated soil creating a quicksand-like condition for a period of time. We extrapolate the nuclear effects experience to a Chicago-based scenario. We consider the TARP (Tunnel and Reservoir Project) and subway system and the underground lifeline (electric, gas, water, etc) system and provide guidance for planning this scenario.

  2. INFORMATION SCENARIOS OVER THE RISK IN INSURANCE

    Directory of Open Access Journals (Sweden)

    Mariana Rodica Tirlea

    2013-07-01

    Full Text Available Risks management means identifying them, assessing, quantifying and strategy to counter them, and finding solutions to some levers to diminish or even eliminate the possibility of developing or their consequences. Hung everywhere, risk is associated with uncertain situations and opportunities. The consequences of risk can result in adverse or positive effects related to the activity of the insurance undertaking or of the reinsurance undertaking. The risk has a pronounced randomly character, and its presence in the field of insurance undertakings and reinsurance. This can be explained by the fact that the risks are taken by these companies and have direct effects on their financial results during the period of validity of the contractual relations. The results of risk effects have an impact on the results of activity of insurance companies. The financial impact of a negative event, exceed the sum of the individual loss, leading in some cases to bankruptcy. The financial impact is due to the positive opportunities, which have not made an appearance, and the first event to transform into income. An important role is the responsibility of the information system, providing solutions based on scenarios, by electronic data processing, consider all types of consequences of a hazard and allow insurance companies and reinsurance, on the other hand, to calculate all the possible consequences of a given event and the ultimate financial impact on them, and finally, to make decisions to base decisions for various insurance products and reinsurance. People insurance records for each situation. In practice the scenario method is only used to make specific estimates for different scenarios depending on the circumstances, which has a certain probability of realization, for the favorable; for the neutral and negative and gives solutions for each individual, taking into account certain criteria. For example, we will present a life insurance in several poses.

  3. On adiabatic perturbations in the ekpyrotic scenario

    Science.gov (United States)

    Linde, A.; Mukhanov, V.; Vikman, A.

    2010-02-01

    In a recent paper, Khoury and Steinhardt proposed a way to generate adiabatic cosmological perturbations with a nearly flat spectrum in a contracting Universe. To produce these perturbations they used a regime in which the equation of state exponentially rapidly changed during a short time interval. Leaving aside the singularity problem and the difficult question about the possibility to transmit these perturbations from a contracting Universe to the expanding phase, we will show that the methods used in Khoury are inapplicable for the description of the cosmological evolution and of the process of generation of perturbations in this scenario.

  4. On adiabatic perturbations in the ekpyrotic scenario

    CERN Document Server

    Linde, A; Vikman, A

    2009-01-01

    In a recent paper arXiv:0910.2230, Khoury and Steinhardt proposed a way to generate adiabatic cosmological perturbations with a nearly flat spectrum in a contracting Universe. To produce these perturbations they used a regime in which the equation of state exponentially rapidly changed during a short time interval. Leaving aside the singularity problem and the difficult question about the possibility to transmit these perturbations from a contracting Universe to the expanding phase, we will show that the methods used in arXiv:0910.2230 are inapplicable for the description of the cosmological evolution and of the process of generation of perturbations in this scenario.

  5. Postulated accident scenarios in weapons disassembly

    Energy Technology Data Exchange (ETDEWEB)

    Payne, S.S. [Dept. of Energy, Albuquerque, NM (United States)

    1997-06-01

    A very brief summary of three postulated accident scenarios for weapons disassembly is provided in the paper. The first deals with a tetrahedral configuration of four generic pits; the second, an infinite planar array of generic pits with varying interstitial water density; and the third, a spherical shell with internal mass suspension in water varying the size and mass of the shell. Calculations were performed using the Monte Carlo Neutron Photon transport code MCNP4A. Preliminary calculations pointed to a need for higher resolution of small pit separation regimes and snapshots of hydrodynamic processes of water/plutonium mixtures.

  6. Scenarios of hydrogen production from wind power

    Energy Technology Data Exchange (ETDEWEB)

    Klaric, Mario

    2010-09-15

    Since almost total amount of hydrogen is currently being produced from natural gas, other ways of cleaner and 'more renewable' production should be made feasible in order to make benchmarks for total 'hydrogen economy'. Hydrogen production from wind power combined with electrolysis imposes as one possible framework for new economy development. In this paper various wind-to-hydrogen scenarios were calculated. Cash flows of asset based project financing were used as decision making tool. Most important parameters were identified and strategies for further research and development and resource allocation are suggested.

  7. CFDP Configuration: Enclid and Juice Scenarios

    Science.gov (United States)

    Valverde, Alberto; Taylor, Chris; Montesinos, Juan Antonio; Maiorano, Elena; Colombo, Cyril; Erd, Christian; Magistrati, Giorgio

    2014-08-01

    This paper presents the work done within the ESA ESTEC Data Systems Division, targeting the implementation of CFDP in future ESA Science Missions. EUCLID and JUICE currently include CCSDS File Delivery Protocol (CFDP) as baseline for payload data transfer to ground. The two missions have completely different characteristics, although both present quite demanding scenarios. Using the communication link characteristics as an input, some simulations have been performed to optimize the CFDP configuration and get some preliminary figures on the retransmission overhead, payload data bandwidth and number of parallel transactions needed to maintain full bandwidth utilization. The paper provides some guidelines on CFDP configuration and usage that can be useful in future CFDP implementations.

  8. Land use scenarios for greater Copenhagen

    DEFF Research Database (Denmark)

    Fertner, Christian; Jørgensen, Gertrud; Nielsen, Thomas Alexander Sick

    2012-01-01

    Urban planning and development in Denmark can be characterised by a relatively strong planning framework. Land use scenarios based on empirically derived dynamics of urban growth are practically never applied. However, modelling approaches do offer a methodology to explore the pressures in an urban...... region, as well as an approach to understand urban development patterns outside the ‘spatial masterplan’. In this context we will present the results of a modelling exercise addressing future land use change in the metropolitan area of Copenhagen, Denmark, and the impact of the current regional planning...

  9. The teaching profession: scenarios, profiles and tendencies

    Directory of Open Access Journals (Sweden)

    Pablo Palomero Fernández

    2010-12-01

    Full Text Available This article introduces the special issue of the Revista Electrónica Interuniversitaria de Formación del Profesorado, 35, volumen 13 (4 entitled The teaching profession: Scenarios, profiles and tendencies. It contains contributions from authors affiliated to twenty-eight different institutions across five countries: Spain, Brazil, Mexico, Argentina and Peru. The twenty-eight articles included are followed by a number of PhD thesis summaries and book reviews, whose general framework is that of the teaching profession.

  10. Improving exposure scenario definitions within REACH

    DEFF Research Database (Denmark)

    Lee, Jihyun; Pizzol, Massimo; Thomsen, Marianne

    instruments to support a precautionary chemicals management system and to protect receptor’s health have also been increasing. Since 2007, the European Union adopted REACH (the Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals): REACH makes industry responsible for assessing...... the different background exposure between two countries allows in fact the definition of a common framework for improving exposure scenarios within REACH system, for monitoring environmental health, and for increasing degree of circularity of resource and substance flows. References 1. European Commission...

  11. Experimental observations of boric acid precipitation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Vaghetto, R., E-mail: r.vaghetto@tamu.edu; Childs, M., E-mail: masonchilds@tamu.edu; Jones, P., E-mail: pgjones87@tamu.edu; Lee, S., E-mail: sayalee@tamu.edu; Kee, E., E-mail: erniekee@gmail.com; Hassan, Y.A., E-mail: y-hassan@tamu.edu

    2017-02-15

    During a Loss of Coolant Accident (LOCA) in Light Water Reactors (LWR), borated water is injected into the core through the safety injection system. The continuous vaporization of the water from the core may increase the concentration of boric acid in the core that, under certain conditions may reach the solubility limit and precipitate. This includes scenarios where the liquid water supply to the core is affected by possible blockages due to debris accumulation. Questions have been raised on the effects of the precipitate in the core on the flow behavior, including the possibility of additional blockages produced by precipitate accumulation. A simple experimental facility was constructed to perform experimental observations of the behavior of borated water under the combined effects of the boiling and the boric acid precipitation (BAP). The facility consists of a transparent polycarbonate vertical pipe where forty-five heated rods have been installed to supply the power to the water to reach the saturation temperature, and maintain a desired boil-off rate. The layout and geometry of the experimental apparatus were conceived to emulate a simplified core of a Pressurized Water Reactor (PWR). Experimental observations have been conducted under two different conditions. Preliminary tests were conducted to observe the behavior of the water and the boric acid precipitate during a boil-off scenario without borated water addition (decreasing water level). During the main test runs, borated water was constantly injected from the top of the test section to maintain a constant mixture level in the test section. Both tests assumed no flow from the bottom of the test section which may be the case of PWR LOCA scenarios in presence of debris-generated core blockage. The observations performed with a set of cameras installed around the test section showed interesting effects of the vapor bubbles on the boric acid precipitate migration and accumulation in the test section. The

  12. Probabilistic results for a mobile service scenario

    DEFF Research Database (Denmark)

    Møller, Jesper; Yiu, Man Lung

    We consider the following stochastic model for a mobile service scenario. Consider a stationary Poisson process in Rd, with its points radially ordered with respect to the origin (the anchor); if d = 2, the points may correspond to locations of e.g. restaurants. A user, with a location different...... the inferred privacy region is a random set obtained by an adversary who only knows the anchor and the points received from the server, where the adversary ‘does the best' to infer the possible locations of the user. Probabilistic results related to the communication cost and the inferred privacy region...

  13. Emergent physics: Fermi-point scenario.

    Science.gov (United States)

    Volovik, Grigory

    2008-08-28

    The Fermi-point scenario of emergent gravity has the following consequences: gravity emerges together with fermionic and bosonic matter; emergent fermionic matter consists of massless Weyl fermions; emergent bosonic matter consists of gauge fields; Lorentz symmetry persists well above the Planck energy; space-time is naturally four dimensional; the Universe is naturally flat; the cosmological constant is naturally small or zero; the underlying physics is based on discrete symmetries; 'quantum gravity' cannot be obtained by quantization of Einstein equations; and there is no contradiction between quantum mechanics and gravity, etc.

  14. Reality based scenarios facilitate knowledge network development.

    Science.gov (United States)

    Manning, J; Broughton, V; McConnell, E A

    1995-03-01

    The challenge in nursing education is to create a learning environment that enables students to learn new knowledge, access previously acquired information from a variety of disciplines, and apply this newly constructed knowledge to the complex and constantly changing world of practice. Faculty at the University of South Australia, School of Nursing, City Campus describe the use of reality based scenarios to acquire domain-specific knowledge and develop well connected associative knowledge networks, both of which facilitate theory based practice and the student's transition to the role of registered nurse.

  15. Intervehicle Communication Research – Communication Scenarios

    Directory of Open Access Journals (Sweden)

    Šarūnas Stanaitis

    2011-03-01

    Full Text Available Recently intervehicle communications are attracting much attention from industry and academia. Upcoming standard for intervehicle communication IEEE 802.11p, known as Wireless Access in Vehicular Environments (WAVE, is still in its draft stage, but already coming into final standardization phase. Problematic, regarding mobile WAVE nodes, are described in several articles, simulations prepared and experiments done. But most of these works do not consider possible maximal communication load. This paper presents intervehicle communication scenario in respect to radio communications, mobility and other aspects of vehicular environments.Article in English

  16. Scenario Prediction and Analysis of Urban Growth Using SLEUTH Model

    Institute of Scientific and Technical Information of China (English)

    FENG Hui-Hui; LIU Hui-Ping; L(U) Ying

    2012-01-01

    Scenario prediction was introduced to better understand urban dynamics and to support urban planning.Taking the Dongguan central urban area of the Pearl River Delta,China as an example,three urban development scenarios,historical trend (HT) scenario,forest protection (FP) scenario,and growth restriction (GR) scenario,were designed and transplanted into the SLEUTH model through the parameter self-modification method.The quantitative analysis results showed that the urban area would expand continuously from 2003 to 2030 under the HT scenario.More land resources would be saved under the GR scenario than FP scenario.Furthermore,the urban growth under the HT and FP scenarios would come to a steady state by 2020,while this deadline of the GR scenario would be postponed to 2025.The spatial pattern analysis using five spatial metrics,class area,number of patches,largest patch index,edge density,and contagion index,showed that under all the scenarios,the urban patches would become bigger and the form would become more compact,and the urban form under the GR scenario would be the smallest and most heterogeneous.These demonstrated that the GR scenario was more effective in meeting the goal of land protection and sustainable development for the study area.

  17. 2015 Standard Scenarios Annual Report: U.S. Electric Sector Scenario Exploration

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Patrick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cole, Wesley [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Blair, Nate [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lantz, Eric [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnan, Venkat [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mai, Trieu [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mulcahy, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Porro, Gian [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-07-16

    This report is one of several products resulting from an initial effort to provide a consistent set of technology cost and performance data and to define a conceptual and consistent scenario framework that can be used in the National Renewable Energy Laboratory’s (NREL’s) future analyses. The long-term objective of this effort is to identify a range of possible futures of the U.S. electricity sector in which to consider specific energy system issues through (1) defining a set of prospective scenarios that bound ranges of key technology, market, and policy assumptions and (2) assessing these scenarios in NREL’s market models to understand the range of resulting outcomes, including energy technology deployment and production, energy prices, and carbon dioxide (CO2) emissions.

  18. Robustness of WLO-scenarios; Bestendigheid van WLO-scenario's

    Energy Technology Data Exchange (ETDEWEB)

    Hilbers, H.; Snellen, D.

    2010-12-15

    Developments in demography, economy and mobility have been showing major fluctuations in the last decade. As a result the question rose whether the WLO future scenarios, which provide an important basis for the spatial policy of the Dutch government, are still usable. This turns out to be the case. Most of the fluctuations of recent years are still within the margins of the sketched scenarios. [Dutch] De ontwikkelingen in demografie, economie en mobiliteit vertonen de laatste tien jaar grote schommelingen. Daarmee rees de vraag of de WLO-toekomstscenario's, die een belangrijke basis vormen voor het ruimtelijk beleid van de rijksoverheid, nog steeds bruikbaar zijn. Dat blijkt zo te zijn. De schommelingen van de laatste jaren vallen merendeels nog steeds binnen de marges van de geschetste scenario's.

  19. Study on Earth Radiation Budget mission scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Dlhopolsky, R.; Hollmann, R.; Mueller, J.; Stuhlmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    The goal of this study is to study optimized satellite configurations for observation of the radiation balance of the earth. We present a literature survey of earth radiation budget missions and instruments. We develop a parametric tool to simulate realistic multiple satellite mission scenarios. This tool is a modular computer program which models satellite orbits and scanning operation. We use Meteosat data sampled at three hour intervals as a database to simulate atmospheric scenes. Input variables are satellite equatorial crossing time and instrument characteristics. Regional, zonal and global monthly averages of shortwave and longwave fluxes for an ideal observing system and several realistic satellite scenarios are produced. Comparisons show that the three satellite combinations which have equatorial crossing times at midmorning, noon and midafternoon provide the best shortwave monitoring. Crossing times near sunrise and sunset should be avoided for the shortwave. Longwave diurnal models are necessary over and surfaces and cloudy regions, if there are only two measurements made during daylight hours. We have found in the shortwave inversion comparison that at least 15% of the monthly regional errors can be attributed to the shortwave anisotropic models used. (orig.) 68 refs.

  20. Sociotechnical scenarios for the Austrian energy system

    Directory of Open Access Journals (Sweden)

    Wächter Petra

    2012-10-01

    Full Text Available Reducing greenhouse gases by 80%, as demanded by the IPCC, is one of the great long-term challenges facing our societies today and will doubtless require transformative changes to current energy regimes. Large-scale system transitions such as the one envisaged for the global energy system in the next 30–40 years can only be realized through complex processes of change involving global, regional, national, and local levels. In this paper we use sociotechnical scenario analysis to contribute ideas for the transformative change of the current Austrian energy system over the long term and to identify some of the particular policy measures, as well as structural changes and broader shifts in perspective, that would be necessary to deal with such challenges. There is less emphasis on the technical issues involved than on the socio-economic and governance requirements such a shift would demand. We also explain our experiences with the sociotechnical scenario process and its outcomes. In particular, we identify examples of some critical issues and opportunities within one of the identified key action fields and discuss their various implications for energy policy and everyday practices.

  1. Beyond Inflation:. A Cyclic Universe Scenario

    Science.gov (United States)

    Turok, Neil; Steinhardt, Paul J.

    2005-08-01

    Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful 'cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both high energy and low energy inflation, with energy densities differing by a hundred orders of magnitude. The questions of why the universe started out undergoing high energy inflation, and why it will end up in low energy inflation, are unanswered. Rather than resort to anthropic arguments, we have developed an alternative cosmology, the cyclic universe [1], in which the universe exists in a very long-lived attractor state determined by the laws of physics. The model shares inflation's phenomenological successes without requiring an epoch of high energy inflation. Instead, the universe is made homogeneous and flat, and scale-invariant adiabatic perturbations are generated during an epoch of low energy acceleration like that seen today, but preceding the last big bang. Unlike inflation, the model requires low energy acceleration in order for a periodic attractor state to exist. The key challenge facing the scenario is that of passing through the cosmic singularity at t = 0. Substantial progress has been made at the level of linearised gravity, which is reviewed here. The challenge of extending this to nonlinear gravity and string theory remains.

  2. Using game scenarios for teaching novice programmers

    Directory of Open Access Journals (Sweden)

    Minjie Hu

    Full Text Available As programming educators we need to find ways to engage our students. The students we see today have been called the Nintendo generation. Such students are continually exposed to fast-paced sound, graphics, animation and games. It can be argued that these are the kinds of things that Nintendo generation students want to develop when learning computer science. As a result, computer programming educators have started to use games to engage and motivate students who are learning programming. However, there are difficulties in teaching novices to program using games. In many cases, it is too complicated for novices to begin programming with the extensive packages, libraries, and available object oriented languages when they are required to develop games. Moreover, the games development may seem trivial to the Nintendo generation if we do not include artificial intelligence (AI. Unfortunately, AI algorithm development is not appropriate for novices who are still trying to grasp the simple syntax and semantics of programming. This paper reports on research that explores how educators can motivate students to learn programming by using simple game scenarios. A revised version of Bloom\\'s taxonomy is employed as a framework to aid in the creation of teaching resources that utilise game scenarios as exemplars, exercises and assessments. Finally, some recommendations are made on how the teaching of programming might be improved through a game approach to teaching and learning.

  3. Knowledge Management in Economic Downturn: Indian Scenario

    Directory of Open Access Journals (Sweden)

    D. Mehta

    2011-10-01

    Full Text Available Knowledge management is becoming an indispensable aspect of most of the modern business organizations. It is considered as a corporate cost savings process to augment performance capabilities with broader availability and utilization of major corporate knowledge assets. Knowledge management is the basis of all planning, all development and all progress ofan organization. It is one of the significant ingredients, which makes the accessibility of acceptance with understanding of learning. With recession encompassing the globe, theorganizations are passionately engaged in cost cutting practices to maintain profitability and competitiveness. When enterprises realize that developing and sharing knowledge is pivotal tosustain a cutting edge, the management can decide to place knowledge management high on their agenda- especially during economic turmoil. The Indian organizations have exceedingly done well during the economic turmoil. The present paper is an attempt to study knowledge management during recession in Indian scenario. Major challenges faced by the organizations are highlighted along with strategies to overcome such challenges are presented by the authors.Keywords: knowledge, knowledge management, recession, innovation, Indian scenario.

  4. Biomass Scenario Model Documentation: Data and References

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.; Newes, E.; Bush, B.; Peterson, S.; Stright, D.

    2013-05-01

    The Biomass Scenario Model (BSM) is a system dynamics model that represents the entire biomass-to-biofuels supply chain, from feedstock to fuel use. The BSM is a complex model that has been used for extensive analyses; the model and its results can be better understood if input data used for initialization and calibration are well-characterized. It has been carefully validated and calibrated against the available data, with data gaps filled in using expert opinion and internally consistent assumed values. Most of the main data sources that feed into the model are recognized as baseline values by the industry. This report documents data sources and references in Version 2 of the BSM (BSM2), which only contains the ethanol pathway, although subsequent versions of the BSM contain multiple conversion pathways. The BSM2 contains over 12,000 total input values, with 506 distinct variables. Many of the variables are opportunities for the user to define scenarios, while others are simply used to initialize a stock, such as the initial number of biorefineries. However, around 35% of the distinct variables are defined by external sources, such as models or reports. The focus of this report is to provide insight into which sources are most influential in each area of the supply chain.

  5. An Experiment on Graph Analysis Methodologies for Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Brothers, Alan J.; Whitney, Paul D.; Wolf, Katherine E.; Kuchar, Olga A.; Chin, George

    2005-09-30

    Visual graph representations are increasingly used to represent, display, and explore scenarios and the structure of organizations. The graph representations of scenarios are readily understood, and commercial software is available to create and manage these representations. The purpose of the research presented in this paper is to explore whether these graph representations support quantitative assessments of the underlying scenarios. The underlying structure of the scenarios is the information that is being targeted in the experiment and the extent to which the scenarios are similar in content. An experiment was designed that incorporated both the contents of the scenarios and analysts’ graph representations of the scenarios. The scenarios’ content was represented graphically by analysts, and both the structure and the semantics of the graph representation were attempted to be used to understand the content. The structure information was not found to be discriminating for the content of the scenarios in this experiment; but, the semantic information was discriminating.

  6. Scenarios for the South African Water Sector in 2025; Presentation

    CSIR Research Space (South Africa)

    Funke, Nicola S

    2012-08-01

    Full Text Available do to ensure they have the scenario information they need to make important decisions at their disposal? • Develop scenarios when needed • Engage with science councils, research organisations and boundary organisations to access latest relevant...

  7. Electrical-Generation Scenarios for China

    Energy Technology Data Exchange (ETDEWEB)

    Kypreos, S.; Krakowski, R.A.

    2002-03-01

    The China Energy Technology Program (CETP) used both optimizing and simulation energy- economic-environmental (E3) models to assess tradeoffs in the electricity-generation sector for a range of fuel, transport, generation, and distribution options. The CETP is composed of a range of technical tasks or activities, including Energy Economics Modeling (EEM, optimizations), Electric Sector Simulation (ESS, simulations), Life Cycle Analyses (LCA, externalization) of energy systems, and Multi-Criteria Decision Analyses (MCDA, integration). The scope of CETP is limited to one province (Shandong), to one economic sector (electricity), and to one energy sector (electricity). This document describes the methods, approaches, limitations, sample results, and future/needed work for the EEM ( optimization-based modeling) task that supports the overall goal of CETP. An important tool used by the EEM task is based on a Linear Programming (LP) optimization model that considers 17 electricity-generation technologies utilizing 14 fuel forms (type, composition, source) in a 7-region transportation model of China's electricity demand and supply system over the period 2000-2030; Shandong is one of the seven regions modeled. The China Regional Electricity Trade Model (CRETM) is used to examine a set of energy-environment-economy E3-driven scenarios to quantify related policy implications. The development of electricity production mixes that are optimized under realistically E3 constraints is determined through regional demands for electricity that respond to exogenous assumptions on income (GDP) and electricity prices through respective time-dependent elasticities. Constraints are applied to fuel prices, transportation limits, resource availability, introduction (penetration) rates of specific technology, and (where applicable) to local, regional, and countrywide emission rates of CO{sub 2}, SO{sub 2} and NO{sub x}. Importantly, future inter- regional energy flows are optimized with

  8. Electrical-Generation Scenarios for China

    Energy Technology Data Exchange (ETDEWEB)

    Kypreos, S.; Krakowski, R.A.

    2002-03-01

    The China Energy Technology Program (CETP) used both optimizing and simulation energy- economic-environmental (E3) models to assess tradeoffs in the electricity-generation sector for a range of fuel, transport, generation, and distribution options. The CETP is composed of a range of technical tasks or activities, including Energy Economics Modeling (EEM, optimizations), Electric Sector Simulation (ESS, simulations), Life Cycle Analyses (LCA, externalization) of energy systems, and Multi-Criteria Decision Analyses (MCDA, integration). The scope of CETP is limited to one province (Shandong), to one economic sector (electricity), and to one energy sector (electricity). This document describes the methods, approaches, limitations, sample results, and future/needed work for the EEM ( optimization-based modeling) task that supports the overall goal of CETP. An important tool used by the EEM task is based on a Linear Programming (LP) optimization model that considers 17 electricity-generation technologies utilizing 14 fuel forms (type, composition, source) in a 7-region transportation model of China's electricity demand and supply system over the period 2000-2030; Shandong is one of the seven regions modeled. The China Regional Electricity Trade Model (CRETM) is used to examine a set of energy-environment-economy E3-driven scenarios to quantify related policy implications. The development of electricity production mixes that are optimized under realistically E3 constraints is determined through regional demands for electricity that respond to exogenous assumptions on income (GDP) and electricity prices through respective time-dependent elasticities. Constraints are applied to fuel prices, transportation limits, resource availability, introduction (penetration) rates of specific technology, and (where applicable) to local, regional, and countrywide emission rates of CO{sub 2}, SO{sub 2} and NO{sub x}. Importantly, future inter- regional energy flows are optimized with

  9. Divide by 4 the emissions: the Negatep scenario; Diviser par 4 nos rejets: le scenario Negatep

    Energy Technology Data Exchange (ETDEWEB)

    Acket, C.; Bacher, P

    2007-01-15

    The Negatep scenario is proposed in the framework of the french energy policy, aiming to divide by 4 the CO{sub 2} emissions for 2050. After an evaluation of the today situation concerning the energy consumption and needs, the scenario proposes some ways of energy conservation in different sectors, other energy sources in place of the fossil fuels, the energy needs by sectors. The last part of the document provides the main consumption posts, the CO{sub 2} releases and the approach. (A.L.B.)

  10. Mediated Scenarios: The Infusion of Art and Design in Scenario Practices

    DEFF Research Database (Denmark)

    Selin, Cynthia Lea

    2014-01-01

    Fellowship investigates scenarios mediated through cutting-edge gaming,visualization, simulation and design techniques. The focus on mediated practices of foresight pushes beyond an infusion of art and design into scenarios in an instrumental way, making moreaesthetically palatable futures. Rather what I......), often fail to meaningfullyconnect with the situation, decision-makers or concerns at hand, and tend to lean towardsexperts. Some of these new mediated practices shift away from more technocratic models ofparticipation that often display an impoverish understanding of the co-production of technologyand...

  11. Towards Validating Game Scenarios for Teaching Conflict Resolution

    DEFF Research Database (Denmark)

    Cheong, Yun-Gyung; Grappiolo, Corrado; Pedersen, Christoffer Holmgård

    2013-01-01

    Teaching conflict resolution skills via serious games has received increasing attention in recent years. This paper describes game scenarios that were developed to evoke variant levels of conflict intensity to children. To validate the scenarios, we implemented a prototype and created videos from...... play-throughs of the prototype. We then carried out a user study and ran statistical analyses to test if children would perceive the game scenarios as intended by scenario designers in terms of conflict....

  12. Scenario-building considerations for financial planning models

    Energy Technology Data Exchange (ETDEWEB)

    Murray, S.; Carino, D.

    1994-12-31

    The construction of scenarios is an essential model-building step in stochastic programming. When a discrete sample of scenarios is chosen to represent a continuity of potential outcomes, scenario choice can impact both solution speed and quality. For financial planning models, techniques are discussed that ensure a scenario set matches moments of the continuous distribution and improvements in solution speed and quality are investigated.

  13. Random Scenario Generation for a Multiple Target Tracking Environment Evaluation

    DEFF Research Database (Denmark)

    Hussain, Dil Muhammad Akbar

    2006-01-01

    The paper presents a simulation study on the generation of a random scenario for the performance of track splitting algorithm on a digital signal processor.  Much of the previous work [1] was done on specific (deterministic) scenarios. One of the reasons for considering the specific scenarios...

  14. Effects of Scenario Planning on Participant Mental Models

    Science.gov (United States)

    Glick, Margaret B.; Chermack, Thomas J.; Luckel, Henry; Gauck, Brian Q.

    2012-01-01

    Purpose: The purpose of this paper is to assess the effects of scenario planning on participant mental model styles. Design/methodology/approach: The scenario planning literature is consistent with claims that scenario planning can change individual mental models. These claims are supported by anecdotal evidence and stories from the practical…

  15. Adaptive memory: the survival scenario enhances item-specific processing relative to a moving scenario.

    Science.gov (United States)

    Burns, Daniel J; Hart, Joshua; Griffith, Samantha E; Burns, Amy D

    2013-01-01

    Nairne, Thompson, and Pandeirada (2007) found that retention of words rated for their relevance to survival is superior to that of words encoded under numerous other deep processing conditions. They suggested that our memory systems might have evolved to confer an advantage for survival-relevant information. Burns, Burns, and Hwang (2011) suggested a two-process explanation of the proximate mechanisms responsible for the survival advantage. Whereas most control tasks encourage only one type of processing, the survival task encourages both item-specific and relational processing. They found that when control tasks encouraged both types of processing, the survival processing advantage was eliminated. However, none of their control conditions included non-survival scenarios (e.g., moving, vacation, etc.), so it is not clear how this two-process explanation would explain the survival advantage when scenarios are used as control conditions. The present experiments replicated the finding that the survival scenario improves recall relative to a moving scenario in both a between-lists and within-list design and also provided evidence that this difference was accompanied by an item-specific processing difference, not a difference in relational processing. The implications of these results for several existing accounts of the survival processing effect are discussed.

  16. A scenario based project portfolio selection

    Directory of Open Access Journals (Sweden)

    Kamran Pourahmadi

    2015-09-01

    Full Text Available One of the primary assumptions in many project portfolio selection is the availability of all parameters. However, in real-world cases, many parameters are under uncertainty and the exact values are unknown in advance. This paper presents a scenario based mathematical model for project portfolio selection when parameters are under uncertainty. The problem considers two objective functions where the first one maximizes the net present value while the second objective function is the minimization of the positive deviations from the allocation of resources. The second objective function is looking for project resource leveling. The resulted model is formulated as mixed integer programming and the problem is analyzed under different conditions.

  17. Stochastic Optimization for Nuclear Facility Deployment Scenarios

    Science.gov (United States)

    Hays, Ross Daniel

    Single-use, low-enriched uranium oxide fuel, consumed through several cycles in a light-water reactor (LWR) before being disposed, has become the dominant source of commercial-scale nuclear electric generation in the United States and throughout the world. However, it is not without its drawbacks and is not the only potential nuclear fuel cycle available. Numerous alternative fuel cycles have been proposed at various times which, through the use of different reactor and recycling technologies, offer to counteract many of the perceived shortcomings with regards to waste management, resource utilization, and proliferation resistance. However, due to the varying maturity levels of these technologies, the complicated material flow feedback interactions their use would require, and the large capital investments in the current technology, one should not deploy these advanced designs without first investigating the potential costs and benefits of so doing. As the interactions among these systems can be complicated, and the ways in which they may be deployed are many, the application of automated numerical optimization to the simulation of the fuel cycle could potentially be of great benefit to researchers and interested policy planners. To investigate the potential of these methods, a computational program has been developed that applies a parallel, multi-objective simulated annealing algorithm to a computational optimization problem defined by a library of relevant objective functions applied to the Ver ifiable Fuel Cycle Simulati on Model (VISION, developed at the Idaho National Laboratory). The VISION model, when given a specified fuel cycle deployment scenario, computes the numbers and types of, and construction, operation, and utilization schedules for, the nuclear facilities required to meet a predetermined electric power demand function. Additionally, it calculates the location and composition of the nuclear fuels within the fuel cycle, from initial mining through

  18. Land use scenarios for greater Copenhagen

    DEFF Research Database (Denmark)

    Fertner, Christian; Jørgensen, Gertrud; Nielsen, Thomas Alexander Sick

    2011-01-01

    development plans. Land use scenarios based on empirically derived dynamics of urban growth are practically never applied. This may be explained by the in-consistency between the logic of spatial master planning - and the organic or driver-dependent character of urban growth assumed by land use modelling...... approaches. However, modelling approaches do offer a methodology to explore the pressures in an urban region, as well as an approach to understand urban development patterns outside the ‘spatial masterplan’. In this context we will present the results of a modelling exercise addressing future land use change...... the Dutch-based Research Institute for Knowledge Systems (RIKS), which has a lot of parallels with the MOLAND approach, known from various research applications. As we are new to land use modelling, this exercise should also illustrate the possibilities of non-modelling experts to elaborate a practical...

  19. Model-based scenarios of Mediterranean droughts

    Directory of Open Access Journals (Sweden)

    M. Weiß

    2007-11-01

    Full Text Available This study examines the change in current 100-year hydrological drought frequencies in the Mediterranean in comparison to the 2070s as simulated by the global model WaterGAP. The analysis considers socio-economic and climate changes as indicated by the IPCC scenarios A2 and B2 and the global general circulation model ECHAM4. Under these conditions today's 100-year drought is estimated to occur 10 times more frequently in the future over a large part of the Northern Mediterranean while in North Africa, today's 100-year drought will occur less frequently. Water abstractions are shown to play a minor role in comparison to the impact of climate change, but can intensify the situation.

  20. Conditional steering under the von Neumann scenario

    Science.gov (United States)

    Mukherjee, Kaushiki; Paul, Biswajit; Karmakar, Sumana; Sarkar, Debasis; Mukherjee, Amit; Bhattacharya, Some Sankar; Roy, Arup

    2017-08-01

    In Phys. Lett. A 166, 293 (1992), 10.1016/0375-9601(92)90711-T, Popescu and Rohrlich characterized nonlocality of pure n -partite entangled systems by studying bipartite violation of local realism when n -2 number of parties perform projective measurements on their particles. A pertinent question in this scenario is whether similar characterization is possible for n -partite mixed entangled states also. In the present work we have followed an analogous approach so as to explore whether given a tripartite mixed entangled state the conditional bipartite states obtained by performing projective measurement on the third party demonstrate a weaker form of nonlocality, quantum steering. We also compare this phenomenon of conditional steering with existing notions of tripartite correlations.

  1. Sustainable Low Carbon Transport Scenarios for India

    DEFF Research Database (Denmark)

    Shukla, P.R.; Dhar, Subash; Mittal, Shivika

    2014-01-01

    Transport sector’s fuel mix which is dominated by the fossil fuel imposes multiple external costs like energy security, air quality and climate change. In this study, alternate future scenarios are designed to explore the transitions of national transport system (till 2050). Several policy options...... and local air quality that can be accrued by mainstreaming climate change polices into national sustainable development goals and sectoral plans are also estimated. There is no silver bullet that would enable the transition towards low carbon transport. An optimal mix of policies that includes fuel economy...... standards, modal shifts and cleaner energy supply is required to align climate and sustainable development goals in the long-term....

  2. Beyond Inflation: A Cyclic Universe Scenario

    CERN Document Server

    Turok, N G; Turok, Neil; Seinhardt, Paul J.

    2005-01-01

    Inflation has been the leading early universe scenario for two decades, and has become an accepted element of the successful `cosmic concordance' model. However, there are many puzzling features of the resulting theory. It requires both high energy and low energy inflation, with energy densities differing by a hundred orders of magnitude. The questions of why the universe started out undergoing high energy inflation, and why it will end up in low energy inflation, are unanswered. Rather than resort to anthropic arguments, we have developed an alternative cosmology, the Cyclic universe, in which the universe exists in a very long-lived attractor state determined by the laws of physics. The model shares inflation's phenomenological successes without requiring an epoch of high energy inflation. Instead, the universe is made homogeneous and flat, and scale-invariant adiabatic perturbations are generated during an epoch of low energy acceleration like that seen today, but preceding the last big bang. Unlike inflat...

  3. Addressing an Uncertain Future Using Scenario Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Afzal S.; Marnay, Chris

    2006-12-15

    The Office of Energy Efficiency and Renewable Energy (EERE) has had a longstanding goal of introducing uncertainty into the analysis it routinely conducts in compliance with the Government Performance and Results Act (GPRA) and for strategic management purposes. The need to introduce some treatment of uncertainty arises both because it would be good general management practice, and because intuitively many of the technologies under development by EERE have a considerable advantage in an uncertain world. For example, an expected kWh output from a wind generator in a future year, which is not exposed to volatile and unpredictable fuel prices, should be truly worth more than an equivalent kWh from an alternative fossil fuel fired technology. Indeed, analysts have attempted to measure this value by comparing the prices observed in fixed-price natural gas contracts compared to ones in which buyers are exposed to market prices (see Bolinger, Wiser, and Golove and (2004)). In addition to the routine reasons for exploring uncertainty given above, the history of energy markets appears to have exhibited infrequent, but troubling, regime shifts, i.e., historic turning points at which the center of gravity or fundamental nature of the system appears to have abruptly shifted. Figure 1 below shows an estimate of how the history of natural gas fired generating costs has evolved over the last three decades. The costs shown incorporate both the well-head gas price and an estimate of how improving generation technology has gradually tended to lower costs. The purpose of this paper is to explore scenario analysis as a method for introducing uncertainty into EERE's forecasting in a manner consistent with the preceding observation. The two questions are how could it be done, and what is its academic basis, if any. Despite the interest in uncertainty methods, applying them poses some major hurdles because of the heavy reliance of EERE on forecasting tools that are deterministic in

  4. Distributed Function Computation in Asymmetric Communication Scenarios

    CERN Document Server

    Agnihotri, Samar

    2009-01-01

    We consider the distributed function computation problem in asymmetric communication scenarios, where the sink computes some deterministic function of the data split among N correlated informants. The distributed function computation problem is addressed as a generalization of distributed source coding (DSC) problem. We are mainly interested in minimizing the number of informant bits required, in the worst-case, to allow the sink to exactly compute the function. We provide a constructive solution for this in terms of an interactive communication protocol and prove its optimality. The proposed protocol also allows us to compute the worst-case achievable rate-region for the computation of any function. We define two classes of functions: lossy and lossless. We show that, in general, the lossy functions can be computed at the sink with fewer number of informant bits than the DSC problem, while computation of the lossless functions requires as many informant bits as the DSC problem.

  5. Cell Load Balancing in Heterogeneous Scenarios

    DEFF Research Database (Denmark)

    Eduardo, Simao; Rodrigues, Antonio; Mihovska, Albena D.

    2013-01-01

    Cell load imbalances in wireless networks degrade performance. Macro and small cell collocated deployments (heterogeneous scenario) constitutes a new problem for load balancing. This paper proposes a novel admission control algorithm for an optimal solution to the assignment of traffic flows....... It jointly performs congestion control and inter-cell interference avoidance by means of a utility describing the cell's channel. Centralized and uncoordinated schemes are studied. The first is defined as an integer linear program, while the second builds on the best channel utility developed for the first...... and combines it with a stochastic admission process. Based on simulation evaluation, it is shown that uncoordinated is near-optimal, while providing a viable solution for uncoordinated small cell deployments. Finally, the best utility developed proved better than the traditional power allocation....

  6. Land use scenarios for greater Copenhagen

    DEFF Research Database (Denmark)

    Fertner, Christian; Jørgensen, Gertrud; Nielsen, Thomas Alexander Sick

    2011-01-01

    Urban planning and development in Denmark can be characterised by a relatively strong planning framework. Projections of the future demand for urban development as well as decisions on how and where to accommodate this demand is part of the planning process and reflected in strategic- and local...... development plans. Land use scenarios based on empirically derived dynamics of urban growth are practically never applied. This may be explained by the in-consistency between the logic of spatial master planning - and the organic or driver-dependent character of urban growth assumed by land use modelling...... approaches. However, modelling approaches do offer a methodology to explore the pressures in an urban region, as well as an approach to understand urban development patterns outside the ‘spatial masterplan’. In this context we will present the results of a modelling exercise addressing future land use change...

  7. LCA Modeling of Waste Management Scenarios

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Simion, F.; Tonini, Davide

    2011-01-01

    Lifecycle assessment (LCA) modeling provides a quantitative statement about resource issues and environmental issues in waste management useful in evaluating alternative management systems and in mapping where major loads and savings take place within existing systems. Chapter 3.1 describes...... the concepts behind LCA modeling and Chapter 3.2 gives an overview of existing models and shows examples of their application. A recent comprehensive review of publicly available LCA studies (WRAP, 2006) concluded that, on a material basis, LCA modeling in general confirms the validity of the waste hierarchy...... and exchange with the energy systems, a comparison of results was hampered on a system level. In addition, differences in waste composition may affect the LCA results. This chapter provides results of LCA modeling of 40 waste management scenarios handling the same municipal waste (MSW) and using different...

  8. PLASMIX management: LCA of six possible scenarios.

    Science.gov (United States)

    Cossu, R; Garbo, F; Girotto, F; Simion, F; Pivato, A

    2017-08-09

    Only a small percentage of the separately collected plastic is recycled. The mechanical selection process of source segregated plastic materials generates considerable amounts of residues that are commonly named as Plasmix. By means of a life cycle assessment (LCA) modelling, the environmental performances of the main Plasmix management options (thermal treatment, energy recovery, and landfilling) were compared. Six treatment scenarios, with different pre-treatment alternatives, were evaluated. Landfilling after waste washing and Plasmix substitution of coke in a blast furnace represent the most favorable options, since the performances of thermal treatment and energy recovery are worsened by specific emissions of a variety of toxic compounds and heavy metals within plastic materials as additives. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Male breast cancer: is the scenario changing

    Directory of Open Access Journals (Sweden)

    Kulkarni Dhananjay M

    2008-06-01

    Full Text Available Abstract Background The overall incidence of male breast cancer is around 1% of all breast cancers and is on the rise. In this review we aim to present various aspects of male breast cancer with particular emphasis on incidence, risk factors, patho-physiology, treatment, prognostic factors, and outcome. Methods Information on all aspects of male breast cancer was gathered from available relevant literature on male breast cancer from the MEDLINE database over the past 32 years from 1975 to 2007. Various reported studies were scrutinized for emerging evidence. Incidence data were also obtained from the IARC, Cancer Mondial database. Conclusion There is a scenario of rising incidence, particularly in urban US, Canada and UK. Even though more data on risk factors is emerging about this disease, more multi-institutional efforts to pool data with large randomized trials to show treatment and survival benefits are needed to support the existing vast emerging knowledge about the disease.

  10. Judgments of culpability in a filicide scenario.

    Science.gov (United States)

    Ferguson, Christopher J; Miller-Stratton, Heather; Heinrich, Emily; Fritz, Stacey; Smith, Shawn

    2008-01-01

    Previous research has indicated that potential jurors are likely to use personal biases, such as those based on gender and ethnicity, in their judgments of culpability of criminal defendants in addition to, or instead of, the facts of the crime. The present paper seeks to extend this literature to the crime of filicide; to examine whether male defendants are judged more harshly than female defendants, as is the case for domestic violence and sexual abuse. 214 participants were provided with a scenario of filicide in which the gender of the perpetrator, the gender of the child, and the family's social class were randomly assigned. Participants were asked to rate the culpability of the defendant in the case. Results indicated that, unlike for other violent crimes, participants did not use gender or social class biases in their judgments of criminal culpability.

  11. Inhomogeneous reheating scenario with DBI fields

    Science.gov (United States)

    Li, Sheng

    2010-08-01

    We discuss a new mechanism which can be responsible for the origin of the primordial perturbation in inflationary models, the inhomogeneous DBI reheating scenario. Light DBI fields fluctuate during inflation, and finally create the density perturbations through modulation of the inflation decay rate. In this note, we investigate the curvature perturbation and its non-Gaussianity from this new mechanism. Presenting generalized expressions for them, we show that the curvature perturbation not only depends on the particular process of decay but is also dependent on the sound speed cs from the DBI action. More interestingly we find that the non-Gaussianity parameter fNL is independent of cs. As an application we exemplify some decay processes which give a viable and detectable non-Gaussianity. Finally we find a possible connection between our model and the DBI-Curvaton mechanism.

  12. The asymptotic safety scenario in quantum gravity

    Energy Technology Data Exchange (ETDEWEB)

    Saueressig, Frank [Institute of Physics, University of Mainz, D-55099 Mainz (Germany)

    2011-07-01

    Asymptotic safety offers the possibility that gravity constitutes a consistent and predictive quantum field theory within Wilsons generalized framework of renormalization. The key ingredient of this scenario is a non-trivial fixed point of the gravitational renormalization group flow which governs the UV behavior of the theory. The fixed point itself thereby guarantees the absence of unphysical UV divergences while its associated finite-dimensional UV-critical surface ensures the predictivity of the resulting quantum theory. This talk summarizes the evidence for the existence of such a fixed point, which emerged from the flow equation for the effective average action, the gravitational beta-functions in 2+{epsilon} dimensions, the 2-Killing vector reduction of the gravitational path-integral and lattice simulations. Possible phenomenological consequences are discussed in detail.

  13. Epidemics scenarios in the "Romantic network"

    CERN Document Server

    Carvalho, Alexsandro M

    2012-01-01

    The structure of sexual contacts, its contacts network and its temporal interactions, play an important role in the spread of sexually transmitted infections. Unfortunately, that kind of data is very hard to obtain. One of the few exceptions is the "Romantic network" which is a complete structure of a real sexual network of a high school. In terms of topology, unlike other sexual networks classified as scale-free network. Regarding the temporal structure, several studies indicate that relationship timing can have effects on diffusion through networks, as relationship order determines transmission routes.With the aim to check if the particular structure, static and dynamic, of the Romantic network is determinant for the propagation of an STI in it, we perform simulations in two scenarios: the static network where all contacts are available and the dynamic case where contacts evolve in time. In the static case, we compare the epidemic results in the Romantic network with some paradigmatic topologies. We further...

  14. Future Scenarios for Mobile Science Learning

    Science.gov (United States)

    Burden, Kevin; Kearney, Matthew

    2016-04-01

    This paper adopts scenario planning as a methodological approach and tool to help science educators reconceptualise their use of mobile technologies across various different futures. These `futures' are set out neither as predictions nor prognoses but rather as stimuli to encourage greater discussion and reflection around the use of mobile technologies in science education. Informed by the literature and our empirical data, we consider four alternative futures for science education in a mobile world, with a particular focus on networked collaboration and student agency. We conclude that `seamless learning', whereby students are empowered to use their mobile technologies to negotiate across physical and virtual boundaries (e.g. between school and out-of-school activities), may be the most significant factor in encouraging educators to rethink their existing pedagogical patterns, thereby realizing some of the promises of contextualised participatory science learning.

  15. Inhomogeneous Reheating Scenario with DBI fields

    CERN Document Server

    Li, Sheng

    2010-01-01

    We discuss a new mechanism which can be responsible for the origin of the primordial perturbation in inflationary models, the inhomogeneous DBI reheating scenario. Light DBI fields fluctuate during inflation, and finally create the density perturbations through modulation of the inflation decay rate. In this note, we investigate the curvature perturbation and its non-Gaussianity from this new mechanism. Presenting generalized expressions for them, we show that the curvature perturbation not only depends on the particular process of decay but is also dependent on the sound speed $c_s$ from the DBI action. More interestingly we find that the non-Gaussianity parameter $f_{NL}$ is independent of $c_s$. As an application we exemplify some decay processes which give a viable and detectable non-Gaussianity. Finally we find a possible connection between our model and the DBI-Curvaton mechanism.

  16. Overview of the Biomass Scenario Model

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Steve [Lexidyne, LLC, Colorado Springs, CO (United States)

    2015-09-01

    This report describes the structure of the October 2012 version of the Biomass Scenario Model (BSM) in considerable detail, oriented towards readers with a background or interest in the underlying modeling structures. Readers seeking a less-detailed summary of the BSM may refer to Peterson (2013). BSM aims to provide a framework for exploring the potential contribution of biofuel technologies to the transportation energy supply for the United States over the next several decades. The model has evolved significantly from the prototype developed as part of the Role of Biomass in America" tm s Energy Future (RBAEF) project. BSM represents the supply chain surrounding conversion pathways for multiple fuel products, including ethanol, butanol, and infrastructure-compatible biofuels such as diesel, jet fuel, and gasoline.

  17. Present and Future Energy Scenario in India

    Science.gov (United States)

    Kumar, S.; Bhattacharyya, B.; Gupta, V. K.

    2014-09-01

    India's energy sector is one of the most critical components of an infrastructure that affects India's economic growth and therefore is also one of the largest industries in India. India has the 5th largest electricity generating capacity and is the 6th largest energy consumer amounting for around 3.4 % of global energy consumption. India's energy demand has grown at 3.6 % pa over the past 30 years. The consumption of the energy is directly proportional to the progress of manpower with ever growing population, improvement in the living standard of the humanity and industrialization of the developing countries. Very recently smart grid technology can attribute important role in energy scenario. Smart grid refers to electric power system that enhances grid reliability and efficiency by automatically responding to system disturbances. This paper discusses the new communication infrastructure and scheme designed to integrate data.

  18. Scenarios in the development of Mediterranean cyclones

    Directory of Open Access Journals (Sweden)

    M. Romem

    2007-07-01

    Full Text Available The Mediterranean is one of the most cyclogenetic regions in the world. The cyclones are concentrated along its northern coasts and their tracks are oriented more or less west-east, with several secondary tracks connecting them to Europe and to North Africa. The aim of this study is to examine scenarios in the development of Mediterranean cyclones, based on five selected winter seasons (October–March. We detected the cyclones subjectively using 6-hourly Sea-Level Pressure maps, based on the NCAR/NCEP reanalysis archive.

    HMSO (1962 has shown that most Mediterranean cyclones (58% enter the Mediterranean from the Atlantic Ocean (through Biscay and Gibraltar, and from the south-west, the Sahara Desert, while the rest are formed in the Mediterranean Basin itself. Our study revealed that only 13% of the cyclones entered the Mediterranean, while 87% were generated in the Mediterranean Basin. The entering cyclones originate in three different regions: the Sahara Desert (6%, the Atlantic Ocean (4%, and Western Europe (3%.

    The cyclones formed within the Mediterranean Basin were found to generate under the influence of external cyclonic systems, i.e. as "daughter cyclones" to "parent cyclones" or troughs. These parent systems are located in three regions: Europe (61%, North Africa and the Red Sea (34.5% and the Mediterranean Basin itself (4.5%. The study presents scenarios in the development of Mediterranean cyclones during the winter season, emphasizing the cyclogenesis under the influence of various external forcing.

    The large difference with respect to the findings of HMSO (1962 is partly explained by the dominance of spring cyclones generating in the Sahara Desert, especially in April and May that were not included in our study period.

  19. Epidemics scenarios in the "Romantic network".

    Directory of Open Access Journals (Sweden)

    Alexsandro M Carvalho

    Full Text Available The networks of sexual contacts together with temporal interactions play key roles in the spread of sexually transmitted infections. Unfortunately, data for this kind of network is scarce. One of the few exceptions, the "Romantic network", is a complete structure of a real sexual network in a high school. Based on many network measurements the authors of the work have concluded that it does not correspond to any other model network. Regarding the temporal structure, several studies indicate that relationship timing can have an effect on the diffusion throughout networks, as relationship order determines transmission routes. The aim is to check if the particular structure, static and dynamic, of the Romantic network is determinant for the propagation of an STI. We performed simulations in two scenarios: the static network where all contacts are available and the dynamic case where contacts evolve over time. In the static case, we compared the epidemic results in the Romantic network with some paradigmatic topologies. In the dynamic scenario, we considered the dynamics of formation of pairs in the Romantic network and we studied the propagation of the diseases. Our results suggest that although this real network cannot be labeled as a Watts-Strogatz network, it is, in regard to the propagation of an STI, very similar to a high disorder network. Additionally, we found that: the effect that any individual contacting an externally infected subject is to make the network closer to a fully connected one, the higher the contact degree of patient zero the faster the spread of the outbreaks, and the epidemic impact is proportional to the numbers of contacts per unit time. Finally, our simulations confirm that relationship timing severely reduced the final outbreak size, and also, show a clear correlation between the average degree and the outbreak size over time.

  20. Lunar transportation scenarios utilising the Space Elevator.

    Science.gov (United States)

    Engel, Kilian A

    2005-01-01

    The Space Elevator (SE) concept has begun to receive an increasing amount of attention within the space community over the past couple of years and is no longer widely dismissed as pure science fiction. In light of the renewed interest in a, possibly sustained, human presence on the Moon and the fact that transportation and logistics form the bottleneck of many conceivable lunar missions, it is interesting to investigate what role the SE could eventually play in implementing an efficient Earth to Moon transportation system. The elevator allows vehicles to ascend from Earth and be injected into a trans-lunar trajectory without the use of chemical thrusters, thus eliminating gravity loss, aerodynamic loss and the need of high thrust multistage launch systems. Such a system therefore promises substantial savings of propellant and structural mass and could greatly increase the efficiency of Earth to Moon transportation. This paper analyzes different elevator-based trans-lunar transportation scenarios and characterizes them in terms of a number of benchmark figures. The transportation scenarios include direct elevator-launched trans-lunar trajectories, elevator launched trajectories via L1 and L2, as well as launch from an Earth-based elevator and subsequent rendezvous with lunar elevators placed either on the near or on the far side of the Moon. The benchmark figures by which the different transfer options are characterized and evaluated include release radius (RR), required delta v, transfer times as well as other factors such as accessibility of different lunar latitudes, frequency of launch opportunities and mission complexity. The performances of the different lunar transfer options are compared with each other as well as with the performance of conventional mission concepts, represented by Apollo.

  1. Future electric scenarios for urban logistics

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    This report is produced by the SAFE Urban Logistics project - a Norden Energy and Transport project that aims to study and analyse the prospect of integrating electric vehicles in the goods distribution of urban areas. The goal of the project is to create next practice solutions, offer promising opportunities for urban logistics operations, in order to become both more efficient and more environmentally sustainable. The SAFE Urban Logistics aims to match business models for making the application of electric vehicles within inner city logistics happen. The project will also create proposals for sustainable suitable technical solutions associated with these business models. This is one out of four reports produced by the project. Read more about the project and get access to all the reports on www.safeproject.eu. This report is the final output of the project and describes four scenarios for the future of urban logistics based on the urbanization and potential political interventions. The described scenarios will be evaluated on environmental effects and describe a potential idea that can bring this future one step closer. An array of potential business and logistics models as well as technical solutions that could be applied in order to integrate EV's on a larger basis are added at the end of the document. It is supposed to act as inspiration for the strategic development of logistics companies as well as local and governmental policies. Knowledge and experiences in this report are mainly taken from Denmark, Norway and Sweden. When it comes to logistic recommendations and experiences, influence from other parts of Europe have also been included. (Author)

  2. Short views and hints on information, knowledge and scenarios

    DEFF Research Database (Denmark)

    Kristiansson, Michael

    2011-01-01

    This article discusses information and knowledge in relation to scenario planning (van der Heijden) and considers the type of information that is relied on/included as well as the nature of knowledge produced by the scenario planning sequence. In addition, the chief tools and processes drawn upon...... in producing the scenario-related knowledge are examined. Furthermore, the author discusses what purposes scenario planning can be used for as well as an evaluative approach to strengths and weaknesses along with the requirements to be made to the scenario planning process and the informational basis...

  3. Short views and hints on information, knowledge and scenarios

    DEFF Research Database (Denmark)

    Kristiansson, Michael

    2011-01-01

    This article discusses information and knowledge in relation to scenario planning (van der Heijden) and considers the type of information that is relied on/included as well as the nature of knowledge produced by the scenario planning sequence. In addition, the chief tools and processes drawn upon...... in producing the scenario-related knowledge are examined. Furthermore, the author discusses what purposes scenario planning can be used for as well as an evaluative approach to strengths and weaknesses along with the requirements to be made to the scenario planning process and the informational basis...

  4. Quantification of Scenario Distance within Generic WINNER Channel Model

    Directory of Open Access Journals (Sweden)

    Milan Narandžić

    2013-01-01

    Full Text Available Starting from the premise that stochastic properties of a radio environment can be abstracted by defining scenarios, a generic MIMO channel model is built by the WINNER project. The parameter space of the WINNER model is, among others, described by normal probability distributions and correlation coefficients that provide a suitable space for scenario comparison. The possibility to quantify the distance between reference scenarios and measurements enables objective comparison and classification of measurements into scenario classes. In this paper we approximate the WINNER scenarios with multivariate normal distributions and then use the mean Kullback-Leibler divergence to quantify their divergence. The results show that the WINNER scenario groups (A, B, C, and D or propagation classes (LoS, OLoS, and NLoS do not necessarily ensure minimum separation within the groups/classes. Instead, the following grouping minimizes intragroup distances: (i indoor-to-outdoor and outdoor-to-indoor scenarios (A2, B4, and C4, (ii macrocell configurations for suburban, urban, and rural scenarios (C1, C2, and D1, and (iii indoor/hotspot/microcellular scenarios (A1, B3, and B1. The computation of the divergence between Ilmenau and Dresden measurements and WINNER scenarios confirms that the parameters of the C2 scenario are a proper reference for a large variety of urban macrocell environments.

  5. Deriving future oriented research and competence requirements based on scenarios

    DEFF Research Database (Denmark)

    Sonne, Anne-Mette; Harmsen, Hanne; Jensen, Birger Boutrup

    The key to a company's survival lies in its ability to adapt itself to an ever changing world. A company's knowledge and competencies must be fitted to the requirements of the environment in which it operates. However, the kind of competencies that ensures a company's survival are not acquired...... prepare for different possible futures do scenario methods offer real value. A way to try to be better prepared for the future is to deduct competence and research needs given different possible future development described in a number of scenarios. Hence, the aim of this paper is to test the use...... of scenarios for this purpose. Most scenario studies report mostly on the scenario construction, were as we want to focus on the suitability of scenario methods as a mean of deducting competence requirements and research needs. Also scenario techniques have mostly been used on either a company level or a macro...

  6. A Water Rich Mars Surface Mission Scenario

    Science.gov (United States)

    Hoffman, Stephen; Andrews, Alida; Joosten, Kent; Watts, Kevin

    2017-01-01

    The surface of Mars once had abundant water flowing on its surface, but now there is a general perception that this surface is completely dry. Several lines of research have shown that there are sources of potentially large quantities of water at many locations on the surface, including regions considered as candidates for future human missions. Traditionally, system designs for these human missions are constrained to tightly recycle water and oxygen, and current resource utilization strategies involve ascent vehicle oxidizer production only. But the assumption of relatively abundant extant water may change this. Several scenarios were constructed to evaluate water requirements for human Mars expeditions to assess the impact to system design if locally produced water is available. Specifically, we have assessed water resources needed for 1) ascent vehicle oxidizer and fuel production, 2) open-loop water and oxygen life support requirements along with more robust usage scenarios, and 3) crew radiation protection augmentation. In this assessment, production techniques and the associated chemistry to transform Martian water and atmosphere into these useful commodities are identified, but production mass and power requirements are left to future analyses. The figure below illustrates the type of water need assessment performed and that will be discussed. There have been several sources of feedstock material discussed in recent literature that could be used to produce these quantities of water. This paper will focus on Mars surface features that resemble glacier-like forms on Earth. Several lines of evidence indicate that some of these features are in fact buried ice, likely remnants from an earlier ice age on Mars. This paper examines techniques and hardware systems used in the polar regions of Earth to access this buried ice and withdraw water from it. These techniques and systems will be described to illustrate options available. A technique known as a Rodriguez Well

  7. A Water Rich Mars Surface Mission Scenario

    Science.gov (United States)

    Hoffman, Stephen J.; Andrews, Alida; Joosten, B. Kent; Watts, Kevin

    2017-01-01

    In an on-going effort to make human Mars missions more affordable and sustainable, NASA continues to investigate the innovative leveraging of technological advances in conjunction with the use of accessible Martian resources directly applicable to these missions. One of the resources with the broadest utility for human missions is water. Many past studies of human Mars missions assumed a complete lack of water derivable from local sources. However, recent advances in our understanding of the Martian environment provides growing evidence that Mars may be more "water rich" than previously suspected. This is based on data indicating that substantial quantities of water are mixed with surface regolith, bound in minerals located at or near the surface, and buried in large glacier-like forms. This paper describes an assessment of what could be done in a "water rich" human Mars mission scenario. A description of what is meant by "water rich" in this context is provided, including a quantification of the water that would be used by crews in this scenario. The different types of potential feedstock that could be used to generate these quantities of water are described, drawing on the most recently available assessments of data being returned from Mars. This paper specifically focuses on sources that appear to be buried quantities of water ice. (An assessment of other potential feedstock materials is documented in another paper.) Technologies and processes currently used in terrestrial Polar Regions are reviewed. One process with a long history of use on Earth and with potential application on Mars - the Rodriguez Well - is described and results of an analysis simulating the performance of such a well on Mars are presented. These results indicate that a Rodriguez Well capable of producing the quantities of water identified for a "water rich" human mission are within the capabilities assumed to be available on the Martian surface, as envisioned in other comparable Evolvable

  8. Future Scenarios for Fission Based Reactors

    Science.gov (United States)

    David, S.

    2005-04-01

    The coming century will see the exhaustion of standard fossil fuels, coal, gas and oil, which today represent 75% of the world energy production. Moreover, their use will have caused large-scale emission of greenhouse gases (GEG), and induced global climate change. This problem is exacerbated by a growing world energy demand. In this context, nuclear power is the only GEG-free energy source available today capable of responding significantly to this demand. Some scenarios consider a nuclear energy production of around 5 Gtoe in 2050, wich would represent a 20% share of the world energy supply. Present reactors generate energy from the fission of U-235 and require around 200 tons of natural Uranium to produce 1GWe.y of energy, equivalent to the fission of one ton of fissile material. In a scenario of a significant increase in nuclear energy generation, these standard reactors will consume the whole of the world's estimated Uranium reserves in a few decades. However, natural Uranium or Thorium ore, wich are not themselves fissile, can produce a fissile material after a neutron capture ( 239Pu and 233U respectively). In a breeder reactor, the mass of fissile material remains constant, and the fertile ore is the only material to be consumed. In this case, only 1 ton of natural ore is needed to produce 1GWe.y. Thus, the breeding concept allows optimal use of fertile ore and development of sustainable nuclear energy production for several thousand years into the future. Different sustainable nuclear reactor concepts are studied in the international forum "generation IV". Different types of coolant (Na, Pb and He) are studied for fast breeder reactors based on the Uranium cycle. The thermal Thorium cycle requires the use of a liquid fuel, which can be reprocessed online in order to extract the neutron poisons. This paper presents these different sustainable reactors, based on the Uranium or Thorium fuel cycles and will compare the different options in term of fissile

  9. Interactive Language Learning through Speech-Enabled Virtual Scenarios

    Directory of Open Access Journals (Sweden)

    Hazel Morton

    2012-01-01

    Full Text Available This paper describes the evaluation of an educational game designed to give learners of foreign languages the opportunity to practice their spoken language skills. Within the speech interactive Computer-Assisted Language Learning (CALL program, scenarios are presented in which learners interact with virtual characters in the target language using speech recognition technology. Two types of interactive scenarios with virtual characters are presented as part of the game: the one-to-one scenarios which take the form of practice question and answer scenarios where the learner interacts with one virtual character and the interactive scenario which is an immersive contextualised scenario where the learner interacts with two or more virtual characters within the scene to complete a (task-based communicative goal. The study presented here compares learners’ subjective attitudes towards the different scenarios. In addition, the study investigates the performance of the speech recognition component in this game. Forty-eight students of English as a Foreign Language (EFL took part in the evaluation. Results indicate that learners’ subjective ratings for the contextualised interactive scenario are higher than for the one-to-one, practice scenarios. In addition, recognition performance was better for these interactive scenarios.

  10. The climatic scenario of global warming; Les scenarios climatiques de rechauffement

    Energy Technology Data Exchange (ETDEWEB)

    Deque, M

    2007-07-01

    This presentation shows how the ARPEGE model, which is the regional model of Meteo-France, responds to the forcing results of the A2 scenario of the GIEC for the parameters of temperature and rainfalls. It emerges from the study that the main impact in France of the climatic change is an increase of the temperature in all seasons, an increase of the rains in winter and a decrease of the rains in summer. (A.L.B.)

  11. Hepatotoxicity and the present herbal hepatoprotective scenario

    Directory of Open Access Journals (Sweden)

    Priyankar Dey

    2013-01-01

    Full Text Available Most of the metabolic and physiological processes of our body as well as the detoxification of various drugs and xenobiotic chemicals occur in the liver. During this detoxification process, the reactive chemical intermediates damage the liver severely. There are several commercially available drugs, consumption of which results in idiosyncratic drug reaction mediated hepatotoxicity. Drug induced hepatotoxicity is a burning problem in this regard and several drugs are withdrawn from the market due to their hepatotoxic nature. Today, worldwide search of non-hepatotoxic drugs, especially potent hepatoprotective drugs have led towards the screening of numerous herbal products. Pharmaceutical companies and scientific communities have started to consider the therapeutic efficiency of the plant-based hepatoprotective remedies. Different herbs are mentioned in various ethnopharmacological practices possessing hepatoprotective capacities and around the globe, such herbs are still used by people to cure certain liver diseases. Therefore, we have documented the various aspects of hepatotoxicity and an overview on the current scenario of the hepatoprotective herbal remedies.

  12. A Hadronic Scenario for the Galactic Ridge

    CERN Document Server

    Gaggero, Daniele; Marinelli, Antonio; Urbano, Alfredo; Valli, Mauro

    2015-01-01

    Several observations from Fermi-LAT, up to few hundred GeV, and from H.E.S.S., up to $\\sim$ 10 TeV, reported an intense $\\gamma$-ray emission from the inner part of the Galactic plane. After the subtraction of point-like contributions, the remaining $\\gamma$-ray spectrum can provide important hints about the cosmic-ray (CR) population in that region. In particular, the diffuse spectrum measured by both Fermi-LAT and H.E.S.S. in the Galactic Ridge is significantly harder with respect to the rest of the Galaxy. These results were recently interpreted in terms of a comprehensive CR transport model which, adopting a spatial dependent diffusion coefficient and convective velocity, reproduces Fermi-LAT results on the whole sky as well as local CR spectra. We showed as that model predicts a significantly harder neutrino diffuse emission compared to conventional scenarios: The predicted signal is able to account for a significant fraction of the astrophysical flux measured by IceCube. In this contribution, we use the...

  13. Nuclear energy education scenario around the world

    Energy Technology Data Exchange (ETDEWEB)

    Barabas, Roberta de Carvalho; Sabundjian, Gaiane, E-mail: praroberta@uol.com.br, E-mail: gdjian@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Nuclear energy has been used as a source of clean energy with many benefits. Nevertheless, it is still addressed with prejudice. The atomic bombing of Hiroshima and Nagasaki during World War II (1945), the Three Mile Island accident (1979), Chernobyl accident (1986), the crash of the cesium-137 in Goiana, Brazil (1987), and the recent accident in Fukushima (2011) may have been responsible for the negative image of nuclear energy. Researches on education have been conducted with students concerning the conceptual and practical issues of nuclear energy. This work aims to review the literature about nuclear energy education around the world in both, elementary school and high school. Since most educational researches on nuclear energy were published after 1980, this literature review covered the researches that have been published since 1980. The data were presented in chronological order. The results from the literature review provided a clear visualization of the global nuclear energy educational scenario, showing that the theme is still addressed with prejudice due to an incorrect view of nuclear energy and a limited view of its benefits. Concerning the science textbooks, the literature reports that the theme should be better addressed, encouraging students to research more about it. The data from this literature review will serve as a reference for a future proposal for a teaching training program for Brazilian science/physics high school teachers using a new teaching approach. (author)

  14. General Relativistic Simulations of the Collapsar Scenario

    CERN Document Server

    DeBrye, N; Aloy, M A; Font, J A

    2013-01-01

    We are exploring the viability of the collapsar model for long-soft gamma-ray bursts. For this we perform state-of-the-art general relativistic hydrodynamic simulations in a dynamically evolving space-time with the CoCoNuT code. We start from massive low metallicity stellar models evolved up to core gravitational instability, and then follow the subsequent evolution until the system collapses forming a compact remnant. A preliminary study of the collapse outcome is performed by varying the typical parameters of the scenario, such as the initial stellar mass, metallicity, and rotational profile of the stellar progenitor. 1D models (without rotation) have been used to test our newly developed neutrino leakage scheme. This is a fundamental piece of our approach as it allows the central remnant (in all cases considered, a metastable high-mass neutron star) to cool down, eventually collapsing to a black hole. In two dimensions, we show that sufficiently fast rotating cores lead to the formation of Kerr black holes...

  15. [Environmental management: critical analysis, scenarios and challenges].

    Science.gov (United States)

    Porto, Marcelo Firpo de Souza; Schütz, Gabriel Eduardo

    2012-06-01

    This article discusses the limits, alternatives and challenges of environmental management in contemporary globalized capitalist societies. It is based on a critical analysis supported by authors from social sciences, political ecology and public health. To this end, we systematize the meaning of hegemonic environmental management in terms of eco-efficiency and its limits to tackle environmental risks and construct democratic processes and societies. We developed four ideal scenarios involving possible combinations of environmental management and democracy. This model served as a base, together with academic studies and the theoretical and militant experience of the authors, for a reflection on the current characteristics and future trends of environmental management and democracy, with emphasis on the reality of Latin America, specifically Brazil. Lastly, we discuss possibilities for social transformation taking into consideration the contradictions and emancipatory alternatives resulting from confrontations between hegemonic tendencies of the market and counter-hegemonic utopias and social movements. The latter assume principles of environmental justice, economic solidarity, agro-ecology and sustainability as well as the construction of new epistemologies.

  16. Dynamical scenarios for chromosome bi-orientation.

    Science.gov (United States)

    Zhang, Tongli; Oliveira, Raquel A; Schmierer, Bernhard; Novák, Béla

    2013-06-18

    Chromosome bi-orientation at the metaphase spindle is essential for precise segregation of the genetic material. The process is error-prone, and error-correction mechanisms exist to switch misaligned chromosomes to the correct, bi-oriented configuration. Here, we analyze several possible dynamical scenarios to explore how cells might achieve correct bi-orientation in an efficient and robust manner. We first illustrate that tension-mediated feedback between the sister kinetochores can give rise to a bistable switch, which allows robust distinction between a loose attachment with low tension and a strong attachment with high tension. However, this mechanism has difficulties in explaining how bi-orientation is initiated starting from unattached kinetochores. We propose four possible mechanisms to overcome this problem (exploiting molecular noise; allowing an efficient attachment of kinetochores already in the absence of tension; a trial-and-error oscillation; and a stochastic bistable switch), and assess their impact on the bi-orientation process. Based on our results and supported by experimental data, we put forward a trial-and-error oscillation and a stochastic bistable switch as two elegant mechanisms with the potential to promote bi-orientation both efficiently and robustly.

  17. Scenario of Architectural Education in India

    Science.gov (United States)

    Dua, S.; Chahal, K. S.

    2014-09-01

    The dictionary meaning of education is to develop mentally and morally. A good holistic architectural education, therefore, is a combination of skills, information, as well as values. It is somewhat unique. The evaluation process is continuous in nature and in addition to the traditional means of assessment, the training in architectural education consists of varied interrelated parts-theory, field visit and studio/workshop. To certain extent the subjective nature of the design studio projects provides challenges and opportunities for both students and faculty members, in terms of acquiring necessary skills at the part of the students, and, necessity to update and upgrade continually with the changing pace at the part of the teachers. Technology continues to grow at a rapid pace; equipping the students to meet the complex demands of the profession; the curriculum structure and focus and value system must facilitate the relationship between general education and specialized study. Architects must acquire and understand the required information and find ways to put it in order and apply it to particular settings especially in this era of MNCs and BPOs. The paper discusses the current scenario of architectural education in India and affirms the need for change in this education from generalized study which had been in practice in twentieth century to a more relevant, specialised, and value-based education addressing technical and humanistic challenges more objectively in these vastly changing, socio-economic and political trends at global and regional levels.

  18. Future Scenario of Renewable Energy in India

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2012-08-01

    Full Text Available This paper presents a review about future scenario of renewable energy in India.Energy is a vital input for economic and social development of any country. With increasing industrialand agricultural activities in the country, the demand for energy is also rising. Solar, wind and biomassare accepted as dependable and widely available renewable sources of energy. To meet the energy requirement for such a fast growingeconomy, India will require an assured supply of 3–5 times more energy than the total energy consumedtoday. The renewable energy is one of the options to meet this requirement Energy is the prime mover of economic growth and is vital to the sustenance of a modern economy. Future economic growth crucially depends on the long-term availability of energy from sources that are affordable, accessible and environmentally friendly. India has obtained application of a variety of renewable energy technologies for use in different sectors too. This paper presents current status, major achievements and future aspects of renewable energy in India. In this paper evaluation of current energy policies for conquering the obstructions and implementing renewables for the future is also been presented.

  19. Adapting water allocation management to drought scenarios

    Directory of Open Access Journals (Sweden)

    P. Giacomelli

    2008-04-01

    Full Text Available Climate change dynamics have significant consequences on water resources on a watershed scale. With water becoming scarcer and susceptible to variation, the planning and reallocation decisions in watershed management need to be reviewed. This research focuses on an in-depth understanding of the current allocation balance of water resources among competitors, placed along the course of the Adda River. In particular, during the summer period, the demand for water dramatically increases. This is due to the increase in irrigation activities in the lower part of the basin and to the highest peaks of tourist inflow, in the Como Lake and Valtellina areas. Moreover, during these months, the hydroelectric reservoirs in the upper part of the Adda River basin (the Valtellina retain most of the volume of water coming from the snow and glacier melt. The existing allocation problem among these different competing users is exacerbated by the decreasing water supplies. The summer of 2003 testified the rise in a number of allocation problems and situations of water scarcity that brought about environmental and economical consequences. The RICLIC project is committed to the understanding of water dynamics on a regional scale, to quantify the volumes involved and offer local communities an instrument to improve a sustainable water management system, within uncertain climate change scenarios.

  20. Z-peaked excess in goldstini scenarios

    CERN Document Server

    Liew, Seng Pei; Mawatari, Kentarou; Sakurai, Kazuki; Vereecken, Matthias

    2015-01-01

    We study a possible explanation of a 3.0 $\\sigma$ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain $\\tilde g\\to g\\tilde\\chi^0_{1,2}\\to gZ\\tilde G'$ becomes dominant, where $\\tilde\\chi^0_{1,2}$ and $\\tilde G'$ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as $m_{\\tilde g}\\sim 900$ GeV, $m_{\\tilde\\chi^0_{1,2}}\\sim 700$ GeV and $m_{\\tilde G'}\\sim 600$ GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  1. Z-peaked excess in goldstini scenarios

    Directory of Open Access Journals (Sweden)

    Seng Pei Liew

    2015-11-01

    Full Text Available We study a possible explanation of a 3.0 σ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain g˜→gχ˜1,20→gZG˜′ becomes dominant, where χ˜1,20 and G˜′ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as mg˜∼1000 GeV, mχ˜1,20∼800 GeV and mG˜′∼600 GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  2. Screening closing scenarios for tactical targets

    Science.gov (United States)

    Sefcik, Jason A.; Lee, Harry C.; Olson, Teresa L. P.

    2002-07-01

    The first step in an automatic image target acquisition system is determining the location of candidate objects. Screening for targets must also be done within a tactical scenario timeframe. The screening process must only require a portion of the processing workload since other algorithms must execute in the same time frame. The detection of these candidate objects is allocated to two functions within the same algorithm. The first is a pre-screener and other is a clutter rejection component that will categorize the object nomination into target or non-target classes. This paper describes a screener that meets the necessary requirements for tactical operations. It uses the magnitude and direction of the image gradient. Locations are nominated by looking at local neighborhoods in this gradient space. Regions of interest are then selected and various features are extracted. These features are selected both for their information content and their ease of calculation. Using a Bayes approach, target candidates are selected as plausible targets of interest.

  3. Quest for potentials in the quintessence scenario

    CERN Document Server

    Hara, Tetsuya

    2016-01-01

    The time variation of the equation of state $w$ for quintessence scenario with a scalar field as dark energy is studied up to the third derivative ($d^3w/da^3$) with respect to the scale factor $a$, in order to predict the future observations and specify the scalar potential parameters with the observables. The third derivative of $w$ for general potential $V$ is derived and applied to several types of potentials. They are the inverse power-law ($V=M^{4+\\alpha}/Q^{\\alpha}$), the exponential ($V=M^4\\exp{(\\beta M/Q)}$), the cosine ($V=M^4(\\cos (Q/f)+1)$) and the Gaussian types ($V=M^4\\exp(-Q^2/\\sigma^2)$), which are prototypical potentials for the freezing and thawing models. If the parameter number for a potential form is $ n$, it is necessary to find at least for $n+2$ independent observations to identify the potential form and the evolution of the scalar field ($Q$ and $ \\dot{Q} $). Such observations would be the values of $ \\Omega_Q, w, dw/da. \\cdots $, and $ dw^n/da^n$. Since four of the above mentioned po...

  4. What is a Natural SUSY scenario?

    CERN Document Server

    Casas, J Alberto; Robles, Sandra; Rolbiecki, Krzysztof; Zaldivar, Bryan

    2014-01-01

    The idea of "Natural SUSY", understood as a supersymmetric scenario where the fine-tuning is as mild as possible, is a reasonable guide to explore supersymmetric phenomenology. In this paper, we re-examine this issue including several improvements, such as the mixing of the fine-tuning conditions for different soft terms and the presence of potential extra fine-tunings that must be combined with the electroweak one. We give tables and plots that allow to easily evaluate the fine-tuning and the corresponding naturalness bounds for any theoretical model defined at any high-energy (HE) scale. Then, we analyze in detail the complete fine-tuning bounds for the unconstrained MSSM, defined at any HE scale. We show that Natural SUSY does {\\em not} demand light stops. Actually, an average stop mass below 800~GeV is disfavored, though one of the stops might be very light. Regarding phenomenology, the most stringent upper bound from naturalness is the one on the gluino mass, which typically sets the present level fine-t...

  5. Microalgae biorefineries: The Brazilian scenario in perspective.

    Science.gov (United States)

    Brasil, B S A F; Silva, F C P; Siqueira, F G

    2016-06-22

    Biorefineries have the potential to meet a significant part of the growing demand for energy, fuels, chemicals and materials worldwide. Indeed, the bio-based industry is expected to play a major role in energy security and climate change mitigation during the 21th century. Despite this, there are challenges related to resource consumption, processing optimization and waste minimization that still need to be overcome. In this context, microalgae appear as a promising non-edible feedstock with advantages over traditional land crops, such as high productivity, continuous harvesting throughout the year and minimal problems regarding land use. Importantly, both cultivation and microalgae processing can take place at the same site, which increases the possibilities for process integration and a reduction in logistic costs at biorefinery facilities. This review describes the actual scenario for microalgae biorefineries integration to the biofuels and petrochemical industries in Brazil, while highlighting the major challenges and recent advances in microalgae large-scale production. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Knowledge sharing in the health scenario.

    Science.gov (United States)

    Lluch-Ariet, Magí; Brugués de la Torre, Albert; Vallverdú, Francesc; Pegueroles-Vallés, Josep

    2014-11-28

    The understanding of certain data often requires the collection of similar data from different places to be analysed and interpreted. Interoperability standards and ontologies, are facilitating data interchange around the world. However, beyond the existing networks and advances for data transfer, data sharing protocols to support multilateral agreements are useful to exploit the knowledge of distributed Data Warehouses. The access to a certain data set in a federated Data Warehouse may be constrained by the requirement to deliver another specific data set. When bilateral agreements between two nodes of a network are not enough to solve the constraints for accessing to a certain data set, multilateral agreements for data exchange are needed. We present the implementation of a Multi-Agent System for multilateral exchange agreements of clinical data, and evaluate how those multilateral agreements increase the percentage of data collected by a single node from the total amount of data available in the network. Different strategies to reduce the number of messages needed to achieve an agreement are also considered. The results show that with this collaborative sharing scenario the percentage of data collected dramaticaly improve from bilateral agreements to multilateral ones, up to reach almost all data available in the network.

  7. Scenario of Architectural Education in India

    Science.gov (United States)

    Dua, S.; Chahal, K. S.

    2014-09-01

    The dictionary meaning of education is to develop mentally and morally. A good holistic architectural education, therefore, is a combination of skills, information, as well as values. It is somewhat unique. The evaluation process is continuous in nature and in addition to the traditional means of assessment, the training in architectural education consists of varied interrelated parts-theory, field visit and studio/workshop. To certain extent the subjective nature of the design studio projects provides challenges and opportunities for both students and faculty members, in terms of acquiring necessary skills at the part of the students, and, necessity to update and upgrade continually with the changing pace at the part of the teachers. Technology continues to grow at a rapid pace; equipping the students to meet the complex demands of the profession; the curriculum structure and focus and value system must facilitate the relationship between general education and specialized study. Architects must acquire and understand the required information and find ways to put it in order and apply it to particular settings especially in this era of MNCs and BPOs. The paper discusses the current scenario of architectural education in India and affirms the need for change in this education from generalized study which had been in practice in twentieth century to a more relevant, specialised, and value-based education addressing technical and humanistic challenges more objectively in these vastly changing, socio-economic and political trends at global and regional levels.

  8. Future seasonal climate change scenarios for Taiwan using a climate scenario generator

    Science.gov (United States)

    Tfwala, Samkele; Chen, Su-Chin

    2017-04-01

    Decision makers, resource managers and engineers demand accurate information regarding future changes in climate and variability to better forecast potential impacts. To acquire information about climate change, dedicated experiments using global and regional climate models are needed. These demand considerable computing capacity and expertise. This study explores the use of simple climate change scenario generators in developing future changes of climate change at national level. Model for the Assessment of Greenhouse-gas Induced Climate Change (MAGGIC) combined with a scenario generator (SCENGEN) is applied. MAGGIC/SCENGEN use results from the Coupled Model Inter-comparison Project Phase 3 - CMIP3 and IPCC fourth assessment report, working group 1 - AR4). Eighteen general circulation models (GCMs) were evaluated based on global and regional performance. From these, 5 models were selected to predict future changes for Taiwan. The models predict temperature increase in all seasons with a high magnitude (3.16 °C) in June-July-August (JJA) season. Precipitation changes vary widely; generally, there is a decline in December-January-February (DJF), March-April-May (MAM) and September-October-November (SON). A significant decline, -8.8 % and -16 %, is observed in MAM by 2020 and 2100, respectively. The study reveals that simple climate change scenarios can be used to predict future changes.

  9. Using scenario planning in public health: anticipating alternative futures.

    Science.gov (United States)

    Neiner, Jennifer A; Howze, Elizabeth H; Greaney, Mary L

    2004-01-01

    Scenario planning is a method for anticipating possible alternative futures. Used widely in business applications, it allows planners to anticipate problems, reevaluate assumptions, and reflect on consequences of those alternative futures. In this article, scenario planning is applied to public health, specifically to illustrate the four steps in scenario planning for public health using a health department's desire to address chronic disease prevention and control. An unhealthy diet and physical inactivity are considered to be key risk factors. The scenarios are presented in table format and are for illustration purposes only. Many other plausible scenarios could be constructed. Scenario planning allows stake-holders to define a desired, shared vision of the future, but more important, they can better prepare public health professionals to be successful in a constantly changing environment.

  10. The scenario-based generalization of radiation therapy margins

    CERN Document Server

    Fredriksson, Albin

    2015-01-01

    We give a scenario-based treatment plan optimization formulation that is equivalent to planning with geometric margins if the scenario doses are calculated using the static dose cloud approximation. If the scenario doses are instead calculated more accurately, then our formulation provides a novel robust planning method that overcomes many of the difficulties associated with previous scenario-based robust planning methods. In particular, our method protects only against uncertainties that can occur in practice, it gives a sharp dose fall-off outside high dose regions, and it avoids underdosage of the target in ``easy'' scenarios. The method shares the benefits of the previous scenario-based robust planning methods over geometric margins for applications where the static dose cloud approximation is inaccurate, such as irradiation with few fields and irradiation with ion beams. These properties are demonstrated on a suite of phantom cases planned for treatment with scanned proton beams subject to systematic set...

  11. Defining Scenarios: Linking Integrated Models, Regional Concerns, and Stakeholders

    Science.gov (United States)

    Hartmann, H. C.; Stewart, S.; Liu, Y.; Mahmoud, M.

    2007-05-01

    Scenarios are important tools for long-term planning, and there is great interest in using integrated models in scenario studies. However, scenario definition and assessment are creative, as well as scientific, efforts. Using facilitated creative processes, we have worked with stakeholders to define regionally significant scenarios that encompass a broad range of hydroclimatic, socioeconomic, and institutional dimensions. The regional scenarios subsequently inform the definition of local scenarios that work with context-specific integrated models that, individually, can address only a subset of overall regional complexity. Based on concerns of stakeholders in the semi-arid US Southwest, we prioritized three dimensions that are especially important, yet highly uncertain, for long-term planning: hydroclimatic conditions (increased variability, persistent drought), development patterns (urban consolidation, distributed rural development), and the nature of public institutions (stressed, proactive). Linking across real-world decision contexts and integrated modeling efforts poses challenges of creatively connecting the conceptual models held by both the research and stakeholder communities.

  12. Transportation energy scenario analysis technical report No. 1: examination of four existing scenarios. [Projections for 1985, 1995, 2010, and 2025

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, M. J.; LaBelle, S. J.; Millar, M.; Walbridge, E. W.

    1978-03-01

    This project aims to provide the DOE Division of Transportation Energy Conservation (TEC) with a long-range forecasting framework in which to evaluate potential changes to the U.S. Transportation system. This initial report examines four existing, but diverse, 50-year scenarios of the future. It describes the scenarios and summarizes the changes in the major transportation system variables that would occur through the year 2025 in each scenario. Projections of variables of interest to TEC are explored, including passenger or ton miles and energy consumption. Each is reported for 1985, 1995, 2010, and 2025 under four scenarios: success, moderate economic growth, energy crisis, and transformation. The philosophy of this project is that the transportation system must support future lifestyles; by examining potential future lifestyles the required transportation system changes can be deduced. The project: (a) develops a set of scenarios that span likely futures; (b) describes the lifestyles in each scenario in order; (c) determines the characteristics of the transportation system supporting those lifestyles; (d) indicates transportation technologies and policies necessary in that system; and (e) derives the energy characteristics of that system. The implications of the four existing scenarios are examined with emphasis on current TEC electric-vehicle development. This preliminary investigation will be followed by detailed-scenario building (modifying existing scenarios or developing new ones) and generation of lifestyles and transportation system demands under each of the scenarios. This work will be reported in October 1978.

  13. Propagation models for non line-of-sight scenarios

    Science.gov (United States)

    Tasu, A. S.; Anchidin, L.; Tamas, R.; Petrescu, T.

    2016-12-01

    The log-normal propagation model is usually applied for scenarios including a line-of-sight path. However, there are many cases that do not include such a propagation path, e.g. indoor transmission and disaster situations, when radio waves have to penetrate trough ruins. In this paper, we show that the log-normal model can also be applied for non line-of-sight transmission. Both indoor scenario and trough-ruins scenario, are investigated.

  14. Exploring Persona-Scenarios - Using Storytelling to Create Design Ideas

    OpenAIRE

    Madsen, Sabine; Nielsen, Lene

    2010-01-01

    International audience; This paper explores the persona-scenario method by investigating how the method can support project participants in generating shared understandings and design ideas. As persona-scenarios are stories we draw on narrative theory to define what a persona-scenario is and which narrative elements it should consist of. Based on an empirical study a key finding is that despite our inherent human ability to construct, tell, and interpret stories it is not easy to write and pr...

  15. Power System Transformation toward Renewables: Investment Scenarios for Germany

    OpenAIRE

    2014-01-01

    We analyze distinctive investment scenarios for the integration of fluctuating renewables in the German power system. Using a combined model for dispatch, transmission, and investment, three different investment options are considered, including gas-fired power plants, pumped hydro storage, and transmission lines. We find that geographically optimized power plant investments dominate in the reference scenarios for 2024 and 2034. In scenarios with decreasedrenewable curtailment, storage and tr...

  16. Scenario projections for future market potentials of biobased bulk chemicals

    OpenAIRE

    Dornburg, V.; Hermann, B.G.; Patel, M.K.

    2008-01-01

    Three scenario projections for future market potentials of biobased bulk chemicals produced by means of white biotechnology are developed for Europe (EU-25) until the year 2050, and potential nonrenewable energy savings, greenhouse gas emission reduction, and land use consequences are analyzed. These scenarios assume benign, moderate, and disadvantageous conditions for biobased chemicals. The scenario analysis yields a broad range of values for the possible market development of white biotech...

  17. Overview of the ARkStorm scenario

    Science.gov (United States)

    Porter, Keith; Wein, Anne; Alpers, Charles; Baez, Allan; Barnard, Patrick L.; Carter, James; Corsi, Alessandra; Costner, James; Cox, Dale; Das, Tapash; Dettinger, Mike; Done, James; Eadie, Charles; Eymann, Marcia; Ferris, Justin; Gunturi, Prasad; Hughes, Mimi; Jarrett, Robert; Johnson, Laurie; Le-Griffin, Hanh Dam; Mitchell, David; Morman, Suzette; Neiman, Paul; Olsen, Anna; Perry, Suzanne; Plumlee, Geoffrey; Ralph, Martin; Reynolds, David; Rose, Adam; Schaefer, Kathleen; Serakos, Julie; Siembieda, William; Stock, Jonathan; Strong, David; Wing, Ian Sue; Tang, Alex; Thomas, Pete; Topping, Ken; Wills, Chris; Jones, Lucile

    2011-01-01

    The U.S. Geological Survey, Multi Hazards Demonstration Project (MHDP) uses hazards science to improve resiliency of communities to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages emergency planners, businesses, universities, government agencies, and others in preparing for major natural disasters. The project also helps to set research goals and provides decision-making information for loss reduction and improved resiliency. The first public product of the MHDP was the ShakeOut Earthquake Scenario published in May 2008. This detailed depiction of a hypothetical magnitude 7.8 earthquake on the San Andreas Fault in southern California served as the centerpiece of the largest earthquake drill in United States history, involving over 5,000 emergency responders and the participation of over 5.5 million citizens. This document summarizes the next major public project for MHDP, a winter storm scenario called ARkStorm (for Atmospheric River 1,000). Experts have designed a large, scientifically realistic meteorological event followed by an examination of the secondary hazards (for example, landslides and flooding), physical damages to the built environment, and social and economic consequences. The hypothetical storm depicted here would strike the U.S. West Coast and be similar to the intense California winter storms of 1861 and 1862 that left the central valley of California impassible. The storm is estimated to produce precipitation that in many places exceeds levels only experienced on average once every 500 to 1,000 years. Extensive flooding results. In many cases flooding overwhelms the state's flood-protection system, which is typically designed to resist 100- to 200-year runoffs. The Central Valley experiences hypothetical flooding 300 miles long and 20 or more miles wide. Serious flooding also occurs in Orange County, Los Angeles County, San Diego, the San Francisco Bay area, and other

  18. Computational studies of origins of life scenarios

    Science.gov (United States)

    Mathew, Damien Cherian

    Understanding the origins of life on Earth is one of the most intriguing problems facing science today. In the research presented here, we apply computational methods to explore origins of life scenarios. In particular, we focus on the origins of the genetic code and the intersection between geochemistry and a primordial "biochemistry" in which mononucleotides could form short oligoucleotide chains. We also apply quantum chemical methods to a modern biochemical reaction, the charging of tRNA by an aminoacyl-tRNA synthetase, in order to shed light on the possible chemistry one may want to consider in problems relating to the origins of life. The question of how codons came to be associated with specific amino acids in the present form of the genetic code is one fundamental part of gaining insight into the origins of life. Carl Woese and coworkers designed a series of experiments to test associations between amino acids and nucleobases that may have played a role in establishing the genetic code. Through these experiments it was found that a property of amino acids called the polar requirement (PR) is correlated to the organization of the codon table. No other property of amino acids has been found that correlates with the codon table as well as PR, indicating that PR is uniquely related to the modern genetic code. Using molecular dynamics simulations of amino acids in solutions of water and dimethylpyridine used to experimentally measure PR, we show that variations in the partitioning between the two phases as described by radial distribution functions correlate well with the measured PRs. Partition coefficients based on probability densities of the amino acids in each phase have the linear behavior with base concentration as suggested by the PR experiments. We also investigate the possible roles of inorganic mineral surfaces in catalysis and stabilization of reactions essential for early forms of replicating systems that could have evolved into biochemical

  19. Occult hepatitis B infection: an evolutionary scenario

    Directory of Open Access Journals (Sweden)

    Lukashov Vladimir V

    2008-12-01

    Full Text Available Abstract Background Occult or latent hepatitis B virus (HBV infection is defined as infection with detectable HBV DNA and undetectable surface antigen (HBsAg in patients' blood. The cause of an overt HBV infection becoming an occult one is unknown. To gain insight into the mechanism of the development of occult infection, we compared the full-length HBV genome from a blood donor carrying an occult infection (d4 with global genotype D genomes. Results The phylogenetic analysis of polymerase, core and X protein sequences did not distinguish d4 from other genotype D strains. Yet, d4 surface protein formed the evolutionary outgroup relative to all other genotype D strains. Its evolutionary branch was the only one where accumulation of substitutions suggests positive selection (dN/dS = 1.3787. Many of these substitutiions accumulated specifically in regions encoding the core/surface protein interface, as revealed in a 3D-modeled protein complex. We identified a novel RNA splicing event (deleting nucleotides 2986-202 that abolishes surface protein gene expression without affecting polymerase, core and X-protein related functions. Genotype D strains differ in their ability to perform this 2986-202 splicing. Strains prone to 2986-202 splicing constitute a separate clade in a phylogenetic tree of genotype D HBVs. A single substitution (G173T that is associated with clade membership alters the local RNA secondary structure and is proposed to affect splicing efficiency at the 202 acceptor site. Conclusion We propose an evolutionary scenario for occult HBV infection, in which 2986-202 splicing generates intracellular virus particles devoid of surface protein, which subsequently accumulates mutations due to relaxation of coding constraints. Such viruses are deficient of autonomous propagation and cannot leave the host cell until it is lysed.

  20. LIG1 polymorphisms: the Indian scenario

    Indian Academy of Sciences (India)

    Amit Kumar Mitra; Ashok Singh; Indian Genome Variation Consortium; Srikanta Kumar Rath

    2014-08-01

    Elucidation of the genetic diversity and relatedness of the subpopulations of India may provide a unique resource for future analysis of genetic association of several critical community-specific complex diseases.We performed a comprehensive exploration of single nucleotide polymorphisms (SNPs) within the gene DNA ligase 1 (LIG1) among a multiethnic panel of Indian subpopulations representative of the ethnic, linguistic and geographical diversity of India using a two-stage design involving DNA resequencing-based SNP discovery followed by SNP validation using sequenom-based genotyping. Thirty SNPs were identified in LIG1 gene using DNA resequencing including three promoter SNPs and one coding SNP. Following SNP validation, the SNPs rs20580/C19008A and rs3730862/C8804T were found to have the most widespread prevalence with noticeable variations in minor allele frequencies both between the Indian subpopulation groups and also from those reported on other major world populations. Subsequently, SNPs found in Indian subpopulations were analysed using bioinformatics-based approaches and compared with SNP data available on major world populations. Further, we also performed genotype–phenotype association analysis of LIG1 SNPs with publicly available data on LIG1 mRNA expression in HapMap samples. Results showed polymorphisms in LIG1 affect its expression and may therefore change its function. Our results stress upon the uniqueness of the Indian population with respect to the worldwide scenario and suggest that any epidemiological study undertaken on the global population should take this distinctiveness in consideration and avoid making generalized conclusions.