WorldWideScience

Sample records for brane world models

  1. 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.

  2. 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.)

  3. 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.

  4. Null fluid collapse in brane world models

    Science.gov (United States)

    Harko, Tiberiu; Lake, Matthew J.

    2014-03-01

    The brane world description of our Universe entails a large extra dimension and a fundamental scale of gravity that may be lower than the Planck scale by several orders of magnitude. An interesting consequence of this scenario occurs in the nature of spherically symmetric vacuum solutions to the brane gravitational field equations, which often have properties quite distinct from the standard black hole solutions of general relativity. In this paper, the spherically symmetric collapse on the brane world of four types of null fluid, governed by the barotropic, polytropic, strange quark "bag" model and Hagedorn equations of state, is investigated. In each case, we solve the approximate gravitational field equations, obtained in the high-density limit, determine the equation which governs the formation of apparent horizons and investigate the conditions for the formation of naked singularities. Though, naively, one would expect the increased effective energy density on the brane to favor the formation of black holes over naked singularities, we find that, for the types of fluid considered, this is not the case. However, the black hole solutions differ substantially from their general-relativistic counterparts and brane world corrections often play a role analogous to charge in general relativity. As an astrophysical application of this work, the possibility that energy emission from a Hagedorn fluid collapsing to form a naked singularity may be a source of GRBs in the brane world is also considered.

  5. A 6-D Brane World Model

    CERN Document Server

    Kanti, Panagiota; Olive, Keith A.; Kanti, Panagiota; Madden, Richard; Olive, Keith A.

    2001-01-01

    We consider a 6D space-time which is periodic in one of the extra dimensions and compact in the other. The periodic direction is defined by two 4-brane boundaries. Both static and non-static exact solutions, in which the internal spacetime has constant radius of curvature, are derived. In the case of static solutions, the brane tensions must be tuned as in the 5D Randall-Sundrum model, however, no additional fine-tuning is necessary between the brane tensions and the bulk cosmological constant. By further relaxing the sole fine-tuning of the model, we derive non-static solutions, describing de Sitter or Anti de Sitter 4D spacetimes, that allow for the fixing of the inter-brane distance and the accommodation of pairs of positive-negative and positive-positive tension branes. Finally, we consider the stability of the radion field in these configurations by employing small, time-dependent perturbations around the background solutions. In analogy with results drawn in 5 dimensions, the solutions describing a de S...

  6. Cosmic strings in Brane World models

    Science.gov (United States)

    Slagter, Reinoud Jan

    2013-02-01

    On a warped 5-dimensional axially symmetric space time an exact solution is found of a bulk scalar field with a cosmological constant. It turns out that from the effective field equations on the brane, where a U(1) scalar-gauge field is present, no signs of the features of a cosmic string with an asymptotically conical space time is found as in the 4D counterpart model. This is caused by the projection of the bulk Weyl tensor on the brane. This could explain why we do not observe cosmic strings.

  7. Universe acceleration in brane world models

    Science.gov (United States)

    Chiou-Lahanas, C.; Diamandis, G. A.; Georgalas, B. C.

    2014-05-01

    We examine the cosmology induced on a brane moving in the background of a five-dimensional black hole, solution of the string effective action. The evolution, determined by the Israel junction conditions is found to be compatible with an accelerating universe with the present day acceleration coming after a decelerating phase. The possible species of the energy-momentum tensor, localized on the brane, for these solutions to be valid are discussed.

  8. Brane-World Gravity.

    Science.gov (United States)

    Maartens, Roy; Koyama, Kazuya

    2010-01-01

    The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+d-dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (∼ TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies - the 5-dimensional Dvali-Gabadadze-Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.

  9. Cosmology of Dilatonic Brane World

    OpenAIRE

    Youm, Donam

    2000-01-01

    We study cosmological solutions in the dilatonic brane world models. The effective four-dimensional equations on the brane are analyzed for the models with one positive tension brane and two branes with tensions of opposite signs. Just as in the non-dilatonic brane case, the conventional Friedmann equations of the four-dimensional universe are reproduced to the leading order in matter energy density for the model with one brane and the introduction of a radion potential is required in order t...

  10. Brane-World Gravity

    Directory of Open Access Journals (Sweden)

    Roy Maartens

    2010-09-01

    Full Text Available The observable universe could be a 1+3-surface (the “brane” embedded in a 1+3+d-dimensional spacetime (the “bulk”, with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (∼ TeV level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity “leaks” into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall–Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies – the 5-dimensional Dvali–Gabadadze–Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.

  11. Brane-World Gravity

    Directory of Open Access Journals (Sweden)

    Maartens Roy

    2004-01-01

    Full Text Available The observable universe could be a 1+3-surface (the "brane" embedded in a 1+3+$d$-dimensional spacetime (the "bulk", with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the $d$ extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak ($sim$TeV level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. General relativity cannot describe gravity at high enough energies and must be replaced by a quantum gravity theory, picking up significant corrections as the fundamental energy scale is approached. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review discusses the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models.

  12. Brane world scenarios

    Indian Academy of Sciences (India)

    February 2003 physics pp. 183–188. Brane world scenarios. DILEEP P JATKAR. Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019, India. Email: dileep@mri.ernet.in. Abstract. .... However, we have to tuneV0 = V1 =24M3k and this is like fine tuning. There are a couple of caveats in the RS model ...

  13. Brane World Models Need Low String Scale

    CERN Document Server

    Antoniadis, Ignatios; Calmet, Xavier

    2011-01-01

    Models with large extra dimensions offer the possibility of the Planck scale being of order the electroweak scale, thus alleviating the gauge hierarchy problem. We show that these models suffer from a breakdown of unitarity at around three quarters of the low effective Planck scale. An obvious candidate to fix the unitarity problem is string theory. We therefore argue that it is necessary for the string scale to appear below the effective Planck scale and that the first signature of such models would be string resonances. We further translate experimental bounds on the string scale into bounds on the effective Planck scale.

  14. Enveloping branes and brane-world singularities.

    Science.gov (United States)

    Antoniadis, Ignatios; Cotsakis, Spiros; Klaoudatou, Ifigeneia

    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.

  15. 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.)

  16. Solitons in Brane Worlds

    CERN Document Server

    Youm, D

    2000-01-01

    We study some aspects of dilatonic domain walls in relation to the Randall-Sundrum model on noncompact internal space. We construct fully localized supergravity solutions describing extreme dilatonic branes within extreme dilatonic domain walls and the BPS branes within the BPS domain walls of string theories. These solutions are valid in any region of spacetime, not just in the region close to the domain walls.

  17. Three-family supersymmetric standardlike models from intersecting brane worlds.

    Science.gov (United States)

    Cvetic, M; Shiu, G; Uranga, A M

    2001-11-12

    We construct the first three family N = 1 supersymmetric string model with standard model gauge group SU(3)(C) x SU(2)(L) x U(1)(Y) from an orientifold of type IIA theory on T(6)/(Z(2) x Z(2)) and D6-branes intersecting at angles. In addition to the minimal supersymmetric standard model particles, the model contains right-handed neutrinos, a chiral (but anomaly-free) set of exotic multiplets, and extra vectorlike multiplets. We discuss some phenomenological features of this model.

  18. Vacuum Brane and the Bulk Dynamics in Dilatonic Brane World

    OpenAIRE

    Ochiai, H; Sato, K.

    2000-01-01

    We investigate the dynamics of vacuum brane and the bulk in dilatonic brane world. We present exact dynamical solutions which describe the vacuum dilatonic brane world. We find that the solution has initial singularity and singularity at spatial infinity.

  19. Probing Solitons in Brane Worlds

    CERN Document Server

    Youm, Donam

    2000-01-01

    We study dynamics of a probe p-brane and a test particle in the field background of fully localized solutions describing the source p-brane within the worldvolume of the source domain wall. We find that the probe dynamics in the background of the source p-brane in one lower dimensions is not reproduced, indicating that p-branes within the worldvolume of domain walls perhaps describe an exotic phase of p-branes in brane worlds. We speculate therefore that a (p+1)-brane where one of its longitudinal directions is along the direction transverse to the domain wall is the right describtion of the p-brane in the brane world with the expected properties.

  20. On Closed Timelike Curves and Warped Brane World Models

    Directory of Open Access Journals (Sweden)

    Slagter Reinoud Jan

    2013-09-01

    Full Text Available At first glance, it seems possible to construct in general relativity theory causality violating solutions. The most striking one is the Gott spacetime. Two cosmic strings, approaching each other with high velocity, could produce closed timelike curves. It was quickly recognized that this solution violates physical boundary conditions. The effective one particle generator becomes hyperbolic, so the center of mass is tachyonic. On a 5-dimensional warped spacetime, it seems possible to get an elliptic generator, so no obstruction is encountered and the velocity of the center of mass of the effective particle has an overlap with the Gott region. So a CTC could, in principle, be constructed. However, from the effective 4D field equations on the brane, which are influenced by the projection of the bulk Weyl tensor on the brane, it follows that no asymptotic conical space time is found, so no angle deficit as in the 4D counterpart model. This could also explain why we do not observe cosmic strings.

  1. On Closed Timelike Curves and Warped Brane World Models

    Science.gov (United States)

    Slagter, Reinoud Jan

    2013-09-01

    At first glance, it seems possible to construct in general relativity theory causality violating solutions. The most striking one is the Gott spacetime. Two cosmic strings, approaching each other with high velocity, could produce closed timelike curves. It was quickly recognized that this solution violates physical boundary conditions. The effective one particle generator becomes hyperbolic, so the center of mass is tachyonic. On a 5-dimensional warped spacetime, it seems possible to get an elliptic generator, so no obstruction is encountered and the velocity of the center of mass of the effective particle has an overlap with the Gott region. So a CTC could, in principle, be constructed. However, from the effective 4D field equations on the brane, which are influenced by the projection of the bulk Weyl tensor on the brane, it follows that no asymptotic conical space time is found, so no angle deficit as in the 4D counterpart model. This could also explain why we do not observe cosmic strings.

  2. Brane-world cosmology and inflation

    Indian Academy of Sciences (India)

    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 ...

  3. Solitons in Brane Worlds, 2

    CERN Document Server

    Youm, D

    2000-01-01

    We study the solution describing a non-extreme dilatonic (p+1)-brane intersecting a D-dimensional extreme dilatonic domain wall, where one of its longitudinal directions is along the direction transverse to the domain wall, in relation to the Randall-Sundrum type model. The dynamics of the probe (p+1)-brane in such source background reproduces that of the probe p-brane in the background of the (D-1)-dimensional source p-brane. However, as for a probe test particle, the dynamics in one lower dimensions is reproduced, only when the source (p+1)-brane is uncharged.

  4. Dynamics and Asymptotics of Brane-Worlds

    Science.gov (United States)

    Antoniadis, I.; Cotsakis, S.; Klaoudatou, I.

    2015-01-01

    The self-tuning mechanism aims to provide a way to address the cosmological constant problem by guarantying the existence of flat brane solutions independently of the brane tension value. In recent work we have studied the asymptotics of different models of brane-worlds, and here we highlight certain interesting behaviors we have encountered in our search for appropriate conditions to avoid finite-distance singularities in flat brane solutions. Finding such conditions offers a framework within which the self-tuning mechanism could be realized.

  5. 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.

  6. Non-BPS Branes of Supersymmetric Brane Worlds

    CERN Document Server

    Brax, P; Lalak, Z; Brax, Philippe; Falkowski, Adam; Lalak, Zygmunt

    2001-01-01

    We consider five-dimensional brane worlds with N=2 gauged supergravity in the bulk coupled supersymmetrically to two boundary branes at the fixed points of a Z_2 symmetry. We analyse two mechanisms that break supersymmetry either by choosing flipped fermionic boundary conditions on the boundary branes or by modifying the gravitino variation to include both Z_2-odd and Z_2-even operators. In all cases we find the corresponding background. Including an even part in the gravitino variation leads to tilted branes. Choosing the flipped boundary conditions leads to AdS_4 branes and stabilized radion in the detuned case, when the expectation value of the even variation is nonzero. Another solution has the interpretation of moving AdS_4 branes separated by a horizon. The solution with moving branes separated by a horizon can be extended to the tuned case. In the presence of a horizon, temperature mediation communicates supersymmetry breakdown to the branes.

  7. Grand unified brane world scenario

    Science.gov (United States)

    Arai, Masato; Blaschke, Filip; Eto, Minoru; Sakai, Norisuke

    2017-12-01

    We present a field theoretical model unifying grand unified theory (GUT) and brane world scenario. As a concrete example, we consider S U (5 ) GUT in 4 +1 dimensions where our 3 +1 dimensional spacetime spontaneously arises on five domain walls. A field-dependent gauge kinetic term is used to localize massless non-Abelian gauge fields on the domain walls and to assure the charge universality of matter fields. We find the domain walls with the symmetry breaking S U (5 )→S U (3 )×S U (2 )×U (1 ) as a global minimum and all the undesirable moduli are stabilized with the mass scale of MGUT. Profiles of massless standard model particles are determined as a consequence of wall dynamics. The proton decay can be exponentially suppressed.

  8. Enveloping branes and brane-world singularities

    CERN Document Server

    Antoniadis, Ignatios; Klaoudatou, Ifigeneia

    2014-01-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows to determine the singularity structure of the solutions. The result is applied to braneworlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parametrizing 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.

  9. Dilatonic p-Branes and Brane Worlds

    CERN Document Server

    Youm, D

    2000-01-01

    We study a general dilatonic p-brane solution in arbitrary dimensions in relation to the Randall-Sundrum scenario. When the p-brane is fully localized along its transverse directions, the Kaluza-Klein zero mode of bulk graviton is not normalizable. When the p-brane is delocalized along its transverse directions except one, the Kaluza-Klein zero mode of bulk graviton is normalizable if the warp factor is chosen to increase, in which case there are singularities at finite distance away from the p-brane. Such delocalized p-brane can be regarded as a dilatonic domain wall as seen in higher dimensions. This unusual property of the warp factor allows one to avoid a problem of dilatonic domain wall with decreasing warp factor that free massive particles are repelled from the domain wall and hit singularities, since massive particles with finite energy are trapped around delocalized p-branes with increasing warp factor by gravitational force and can never reach the singularities.

  10. 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.

  11. Bare and effective fluid description in brane world cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Norman [Universidad de Santiago, Departamento de Fisica, Facultad de Ciencia, Casilla 307, Santiago (Chile); Lepe, Samuel; Saavedra, Joel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Casilla 4950, Valparaiso (Chile); Pena, Francisco [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile)

    2010-03-15

    An effective fluid description, for a brane world model in five dimensions, is discussed for both signs of the brane tension. We found several cosmological scenarios where the effective equation differs widely from the bare equation of state. For universes with negative brane tension, with a bare fluid satisfying the strong energy condition, the effective fluid can cross the barrier {omega} {sub eff}=-1. (orig.)

  12. Dynamics of test particles and pointlike gyroscopes in the brane world and other 5D models

    Science.gov (United States)

    Seahra, Sanjeev S.

    2002-06-01

    We study the dynamics of test particles and pointlike gyroscopes in 5D manifolds such as those used in the Randall-Sundrum brane world and noncompact Kaluza-Klein models. Our analysis is based on a covariant foliation of the manifold using (3+1)-dimensional spacetime slices orthogonal to the extra dimension, and is hence similar to the Arnowitt-Deser-Misner 3+1 split in ordinary general relativity. We derive gauge invariant equations of motion for freely falling test particles in the 5D and 4D affine parametrizations and contrast these results with previous work concerning the so-called ``fifth force.'' Motivated by the conjectured localization of matter fields on a 3-brane, we derive the form of the classical nongravitational force required to confine particles to a 4D hypersurface and show that the resulting trajectories are geometrically identical to the spacetime geodesics of Einstein's theory. We then discuss the issue of determining the 5D dynamics of a torque-free spinning body in the point-dipole approximation, and then perform a covariant (3+1)+1 decomposition of the relevant formulas (i.e., the 5D Fermi-Walker transport equation) for the cases of freely falling and hypersurface-confined point gyroscopes. In both cases, the 4D spin tensor is seen to be subject to an anomalous torque. We solve the spin equations for a gyroscope confined to a single spacetime section in a simple 5D cosmological model and observe a cosmological variation of the magnitude and orientation of the 4D spin.

  13. Gravity on codimension 2 brane worlds

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Ignacio; /Durham U., IPPP; Santiago, Jose; /Durham U., IPPP /Fermilab

    2004-11-01

    The authors compute the matching conditions for a general thick codimension 2 brane, a necessary previous step towards the investigation of gravitational phenomena in co-dimension 2 braneworlds. They show that, provided the brane is weakly curved, they are specified by the integral in the extra dimensions of the brane energy-momentum, independently of its detailed internal structure. These general matching conditions can then be used as boundary conditions for the bulk solution. By evaluating Einstein equations at the brane boundary they are able to write an evolution equation for the induced metric on the brane depending only on physical brane parameters and the bulk energy-momentum tensor. They particularize to a cosmological metric and show that a realistic cosmology can be obtained in the simplest case of having just a non-zero cosmological constant in the bulk. They point out several parallelisms between this case and the codimension 1 brane worlds in an AdS space.

  14. Warped Brane Worlds in Six Dimensional Supergravity

    CERN Document Server

    Aghababaie, Y; Cline, J M; Firouzjahi, H; Parameswaran, S L; Quevedo, Fernando; Tasinato, G; Zavala, I

    2003-01-01

    We present warped compactification solutions of six-dimensional supergravity, which are generalizations of the Randall-Sundrum warped brane world to codimension two and to a supersymmetric context. In these solutions the dilaton varies over the extra dimensions, and this makes the electroweak hierarchy only power-law sensitive to the proper radius of the extra dimensions (as opposed to being exponentially sensitive as in the RS model). Warping changes the phenomenology of these models because the Kaluza-Klein gap can be much larger than the internal space's inverse proper radius. We provide examples both for Romans' nonchiral supergravity and Salam-Sezgin chiral supergravity, and in both cases the solutions break all of the supersymmetries of the models. We interpret the solution as describing the fields sourced by a 3-brane and a boundary 4-brane (Romans' supergravity) or by one or two 3-branes (Salam-Sezgin supergravity), and we identify the topological constraints which are required by this interpretation....

  15. String inspired brane world cosmology.

    Science.gov (United States)

    Germani, Cristiano; Sopuerta, Carlos F

    2002-06-10

    We consider brane world scenarios including the leading correction to the Einstein-Hilbert action suggested by superstring theory, the Gauss-Bonnet term. We obtain and study the complete set of equations governing the cosmological dynamics. We find they have the same form as those in Randall-Sundrum scenarios but with time-varying four-dimensional gravitational and cosmological constants. By studying the bulk geometry we show that this variation is produced by bulk curvature terms parametrized by the mass of a black hole. Finally, we show there is a coupling between these curvature terms and matter that can be relevant for early universe cosmology.

  16. Brane worlds in critical gravity

    Science.gov (United States)

    Chen, Feng-Wei; Liu, Yu-Xiao; Zhong, Yuan; Wang, Yong-Qiang; Wu, Shao-Feng

    2013-11-01

    Recently, Lü and Pope proposed critical gravities in [Phys. Rev. Lett. 106, 181302 (2011)]. In this paper we construct analytic brane solutions in critical gravity with matter. The Gibbons-Hawking surface term and junction condition are investigated, and the thin and thick brane solutions are obtained. All these branes are embedded in five-dimensional anti-de Sitter spacetimes. Our solutions are stable against scalar perturbations, and the zero modes of scalar perturbations cannot be localized on the branes.

  17. Born-Infeld strings in brane worlds

    CERN Document Server

    Brihaye, Y; Brihaye, Yves; Hartmann, Betti

    2004-01-01

    We study Born-Infeld strings in a six dimensional brane world scenario recently suggested by Giovannini, Meyer and Shaposhnikov (GMS). In the limit of the Einstein-Abelian-Higgs model, we classify the solutions found by GMS. Especially, we point out that the warped solutions, which lead to localisation of gravity, are the - by the presence of the cosmological constant - deformed inverted string solutions. Further, we construct the Born-Infeld analogues of the anti-warped solutions, while a analytic argument leads us to a "no-go'' hypothesis: solutions which localise gravity do NOT exist in a 6 dimensional Einstein-Born-Infeld-Abelian-Higgs (EBIAH) brane world scenario. This latter hypothesis is confirmed by our numerical results.

  18. Rotating black holes in brane worlds

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Valeri P.; Stojkovic, Dejan; Fursaev, Dmitri V. E-mail: fursaev@thsun1.jinr.ru

    2004-06-01

    We study interaction of rotating higher dimensional black holes with a brane in space-times with large extra dimensions. We demonstrate that a rotating black hole attached to a brane can be stationary only if the null Killing vector generating the black hole horizon is tangent to the brane world-sheet. The characteristic time when a rotating black hole with the gravitational radius r{sub 0} reaches this final stationary state is T {approx} r{sub 0}{sup p}'-'1/(G{sigma}), where G is the higher dimensional gravitational coupling constant, {sigma} is the brane tension, and p is the number of extra dimensions. (author)

  19. Warped brane worlds in critical gravity

    Science.gov (United States)

    Zhong, Yi; Chen, Feng-Wei; Xie, Qun-Ying; Liu, Yu-Xiao

    2014-12-01

    We investigate the brane models in arbitrary dimensional critical gravity presented in Lu and Pope (Phys Rev Lett 106:181302, 2011). For the models of the thin branes with codimension one, the Gibbons-Hawking surface term and the junction conditions are derived, with which the analytical solutions for the flat, AdS, and dS branes are obtained at the critical point of the critical gravity. It is found that all these branes are embedded in an AdS spacetime, but, in general, the effective cosmological constant of the AdS spacetime is not equal to the naked one in the critical gravity, which can be positive, zero, and negative. Another interesting result is that the brane tension can also be positive, zero, or negative, depending on the symmetry of the thin brane and the values of the parameters of the theory, which is very different from the case in general relativity. It is shown that the mass hierarchy problem can be solved in the braneworld model in the higher-derivative critical gravity. We also study the thick brane model and find analytical and numerical solutions of the flat, AdS, and dS branes. It is found that some branes will have inner structure when some parameters of the theory are larger than their critical values, which may result in resonant KK modes for some bulk matter fields. The flat branes with positive energy density and AdS branes with negative energy density are embedded in an -dimensional AdS spacetime, while the dS branes with positive energy density are embedded in an -dimensional Minkowski one.

  20. Randall-Sundrum model with {lambda}<0 and bulk brane viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Lepe, Samuel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4950, Valparaiso (Chile); Pena, Francisco [Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Universidad de la Frontera, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile); Saavedra, Joel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4950, Valparaiso (Chile)], E-mail: joel.saavedra@ucv.cl

    2008-04-17

    We study the effect of the inclusion of bulk brane viscosity on brane world (BW) cosmology in the framework of the Eckart's theory, we focus in the Randall-Sundrum model with negative tension on the brane.

  1. Kasner-AdS spacetime and anisotropic brane-world cosmology

    OpenAIRE

    Frolov, Andrei V.

    2001-01-01

    Anisotropic generalization of Randall and Sundrum brane-world model is considered. A new class of exact solutions for brane and bulk geometry is found; it is related to anisotropic Kasner solution. In view of this, the old question of isotropy of initial conditions in cosmology rises once again in the brane-world context.

  2. Rotating black holes in brane worlds

    OpenAIRE

    Frolov, Valeri P.; Fursaev, Dmitri V.; Stojkovic, Dejan

    2004-01-01

    We study interaction of rotating higher dimensional black holes with a brane in space-times with large extra dimensions. We demonstrate that a rotating black hole attached to a brane can be stationary only if the null Killing vector generating the black hole horizon is tangent to the brane world-sheet. The characteristic time when a rotating black hole with the gravitational radius $r_0$ reaches this final stationary state is $T\\sim r_0^{p-1}/(G\\sigma)$, where $G$ is the higher dimensional gr...

  3. Electromagnetic perturbations in new brane world scenarios

    Science.gov (United States)

    Molina, C.; Pavan, A. B.; Medina Torrejón, T. E.

    2016-06-01

    In this work, we consider electromagnetic dynamics in Randall-Sundrum branes. It is derived from a family of four-dimensional spacetimes compatible with Randall-Sundrum brane worlds, focusing on asymptotic flat backgrounds. Maximal extensions of the solutions are constructed, and their causal structures are discussed. These spacetimes include singular, nonsingular, and extreme black holes. Maxwell's electromagnetic field is introduced, and its evolution is studied in an extensive numerical survey. Electromagnetic quasinormal mode spectra are derived and analyzed with time-dependent and high-order WKB methods. Our results indicate that the black holes in the brane are electromagnetically stable.

  4. Scalar fluctuations in dilatonic brane-worlds

    CERN Document Server

    Bozza, Valerio; Veneziano, Gabriele

    2001-01-01

    We derive and solve the full set of scalar perturbation equations for a class of five-dimensional brane--world solutions, with a dilaton scalar field coupled to the bulk cosmological constant and to a 3-brane. The spectrum contains one localized massless scalar mode, to be interpreted as an effective dilaton on the brane, inducing long--range scalar interactions. Two massive scalar modes yield corrections to Newton's law at short distances, which persist even in the limit of vanishing dilaton (namely, in the standard Randall--Sundrum configuration).

  5. Brane-world cosmic strings revive the cosmological constant

    Science.gov (United States)

    Heydari-Fard, M.; Razmi, H.; Rokni, S. Y.

    2013-08-01

    We obtain the static and cylindrically symmetric vacuum solutions of Einstein’s field equations in the framework of the brane-world model where the matter is localized on the brane by means of a confining potential. Considering a constant curvature bulk, one interesting solution is studied, which is similar to the cosmic string solution in a de Sitter spacetime which confirms the idea that the extra geometrical terms in the gravitational field equations on the brane may be the origin of a positive cosmological constant which is responsible for the accelerating expansion of the universe. Finally, we investigate the physical properties of this solution.

  6. Brane-World Inflation:. Perturbations and Cosmological Constraints

    Science.gov (United States)

    Bouhmadi-Lopez, Mariam; Chen, Pisin; Liu, Yen-Wei

    2013-12-01

    A generalization of the Randall-Sundrum single brane-world scenario (RS2) is considered, which is based on adding two curvature corrections: a Gauss-Bonnet (GB) term in the bulk and an induced gravity (IG) term on the brane. Here we are mainly interested in analysing the early inflationary era of the brane, which we model within the extreme slow-roll limit, being the inflaton field confined on the brane. We compute the scalar perturbations on this model and compare our results with those previously obtained for the RS2 scenario with or without a single curvature correction corresponding to a GB or an IG curvature term. Finally, we constrain the model using the latest WMAP7 data.

  7. Soliton models for thick branes

    Energy Technology Data Exchange (ETDEWEB)

    Peyravi, Marzieh [Ferdowsi University of Mashhad, Department of Physics, School of Sciences, Mashhad (Iran, Islamic Republic of); Riazi, Nematollah [Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of); Lobo, Francisco S.N. [Faculdade de Ciencias da Universidade de Lisboa, Instituto de Astrofisica e Ciencias do Espaco, Lisbon (Portugal)

    2016-05-15

    In this work, we present new soliton solutions for thick branes in 4+1 dimensions. In particular, we consider brane models based on the sine-Gordon (SG), φ{sup 4} and φ{sup 6} scalar fields, which have broken Z{sub 2} symmetry in some cases and are responsible for supporting and stabilizing the thick branes. The origin of the symmetry breaking in these models resides in the fact that the modified scalar field potential may have non-degenerate vacua. These vacua determine the cosmological constant on both sides of the brane. We also study the geodesic equations along the fifth dimension, in order to explore the particle motion in the neighborhood of the brane. Furthermore, we examine the stability of the thick branes, by determining the sign of the w{sup 2} term in the expansion of the potential for the resulting Schroedinger-like equation, where w is the five-dimensional coordinate. It turns out that the φ{sup 4} brane is stable, while there are unstable modes for certain ranges of the model parameters in the SG and φ{sup 6} branes. (orig.)

  8. Bounded Scalar Perturbations in Bouncing Brane World Cosmologies

    CERN Document Server

    Maier, Rodrigo; Soares, Ivano Damião

    2013-01-01

    We examine the dynamics of scalar perturbations in closed Friedmann-Lema\\^itre-Robertson- Walker (FLRW) universes in the framework of Brane World theory with a timelike extra dimension. In this scenario, the unperturbed Friedmann equations contain additional terms arising from the bulk-brane interaction that implement non-singular bounces in the models with a cosmological constant and non-interacting perfect fluids. The structure of the phase-space of the models allows for two basic configurations, namely, one bounce solutions or eternal universes. Assuming that the matter content of the model is given by dust and radiation, we derive the dynamical field equations for scalar hydrodynamical perturbations considering either a conformally flat (de Sitter) bulk or a perturbed bulk. We perform a numerical analysis which can shed some light on the study of cosmological scalar perturbations in bouncing brane world models. From a mathematical point of view we show that although the bounce enhances the amplitudes of s...

  9. Cosmological Brane World Solutions with Bulk Scalar Fields

    OpenAIRE

    Davis, Stephen C.

    2001-01-01

    Cosmological brane world solutions are found for five-dimensional bulk spacetimes with a scalar field. A supergravity inspired method for obtaining static solutions is combined with a method for finding brane cosmologies with constant bulk energies. This provides a way to generate full (bulk and brane) cosmological solutions to brane worlds with bulk scalar fields. Examples of these solutions, and their cosmological evolution, are discussed.

  10. Brane-world solutions, standard cosmology, and dark radiation

    OpenAIRE

    Mukohyama, Shinji

    1999-01-01

    New exact solutions of brane-world cosmology are given. These solutions include an arbitrary constant C, which is determined by the geometry outside the brane and which affects the cosmological evolution in the brane-world. If C is zero, then the standard cosmology governs the brane-world as a low-energy effective cosmological theory. However, if C is not zero, then even in low-energy the brane-world cosmology gives predictions different from the standard one. The difference can be understood...

  11. Brane worlds in gravity with auxiliary fields

    Science.gov (United States)

    Guo, Bin; Liu, Yu-Xiao; Yang, Ke

    2015-02-01

    Recently, Pani et al. explored a new theory of gravity by adding nondynamical fields, i.e., gravity with auxiliary fields (Phys Rev D 88:121502, 2013). In this gravity theory, higher-order derivatives of matter fields generically appear in the field equations. In this paper we extend this theory to any dimensions and discuss the thick braneworld model in five dimensions. Domain wall solutions are obtained numerically. The stability of the brane system under tensor perturbations is analyzed. We find that the system is stable under tensor perturbations and the gravity zero mode is localized on the brane. Therefore, the four-dimensional Newtonian potential can be realized on the brane.

  12. Grand unification in the heterotic brane world

    Energy Technology Data Exchange (ETDEWEB)

    Vaudrevange, Patrick Karl Simon

    2008-08-15

    String theory is known to be one of the most promising candidates for a uni ed description of all elementary particles and their interactions. Starting from the ten-dimensional heterotic string, we study its compactification on six-dimensional orbifolds. We clarify some important technical aspects of their construction and introduce new parameters, called generalized discrete torsion. We identify intrinsic new relations between orbifolds with and without (generalized) discrete torsion. Furthermore, we perform a systematic search for MSSM-like models in the context of Z{sub 6}-II orbifolds. Using local GUTs, which naturally appear in the heterotic brane world, we construct about 200 MSSM candidates. We find that intermediate SUSY breaking through hidden sector gaugino condensation is preferred in this set of models. A specific model, the so-called benchmark model, is analyzed in detail addressing questions like the identification of a supersymmetric vacuum with a naturally small {mu}-term and proton decay. Furthermore, as vevs of twisted fields correspond to a resolution of orbifold singularities, we analyze the resolution of Z{sub 3} singularities in the local and in the compact case. Finally, we exemplify this procedure with the resolution of a Z{sub 3} MSSM candidate. (orig.)

  13. D-brane models with non-linear supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, I.; Benakli, K. E-mail: karim.benakli@cern.ch; Laugier, A

    2002-06-03

    We study a class of type I string models with supersymmetry broken on the world-volume of some D-branes and vanishing tree-level potential. Despite the non-supersymmetric spectrum, supersymmetry is non-linearly realized on these D-branes, while it is spontaneously broken in the bulk by Scherk-Schwarz boundary conditions. These models can easily accommodate 3-branes with interesting gauge groups and chiral fermions. We also study the effective field theory and in particular we compute the four-fermion couplings of the localized goldstino with the matter fermions on the brane.

  14. Brane-world cosmology and inflation

    Indian Academy of Sciences (India)

    will appear an effective non-zero cosmological constant on the brane and the brane may undergo inflation solely due to the dynamics in the bulk [11]. It is therefore interesting to investigate the possibility of inflation on the brane without introducing an inflaton on the brane. For this purpose, let us for simplicity consider a ...

  15. Topics in brane world and quantum field theory

    Science.gov (United States)

    Corradini, Olindo

    In the first part of the thesis we study various issues in the Brane World scenario with particular emphasis on gravity and the cosmological constant problem. First, we study localization of gravity on smooth domain-wall solutions of gravity coupled to a scalar field. In this context we discuss how the aforementioned localization is affected by including higher curvature terms in the theory, pointing out among other things that, general combinations of such terms lead to delocalization of gravity with the only exception of the Gauss-Bonnet combination (and its higher dimensional counterparts). We then find a solitonic 3-brane solution in 6D bulk in the Einstein-Hilbert-Gauss-Bonnet theory of gravity. Near to the brane the metric is that for a product of the 4D flat Minkowski space with a 2D wedge whose deficit angle is proportional to the brane tension. Consistency tests imposed on such backgrounds appear to require the localized matter on the brane to be conformal. We then move onto infinite volume extra dimension Brane World scenarios where we study gravity in a codimension-2 model, generalizing the work of Dvali, Gabadadze and Porrati to tensionful branes. We point out that, in the presence of the bulk Gauss-Bonnet combination, the Einstein-Hilbert term is induced on the brane already at the classical level. Consistency tests are presented here as well. To conclude we discuss, using String Theory, an interesting class of large-N gauge theories which have vanishing energy density even though these theories are non-covariant and non-supersymmetric. In the second part of the thesis we study a formulation of Quantum Mechanical Path Integrals in curved space. Such Path Integrals present superficial divergences which need to be regulated. We perform a three-loop calculation in mode regularization as a nontrivial check of the non-covariant counterterms required by such scheme. We discover that dimensional regularization can be successfully adopted to evaluate the

  16. Schwarzschild Black Branes and Strings in higher-dimensional Brane Worlds

    CERN Document Server

    Kanti, Panagiota; Tamvakis, Kyriakos

    2002-01-01

    We consider branes embedded in spacetimes of codimension 1 and 2, with a warped metric tensor for the subspace parallel to the brane. We study a variety of brane-world solutions arising by introducing a Schwarzschild-like black hole metric on the brane and we investigate the properties of the corresponding higher-dimensional spacetime. We demonstrate that normalizable bulk modes lead to a vanishing flow of energy through the naked singularities. From this point of view, these singularities are harmless. (28 refs).

  17. Aspects of M-5 brane world volume dynamics

    OpenAIRE

    Berman, David S

    2003-01-01

    This paper studies various aspects of the world volume dynamics of the M-theory five-brane, including: non-BPS solutions and solution generating symmetries; the scattering properties of world volume solutions; and the equivalence with probe brane dynamics.

  18. Dynamics of Scalar field in a Brane World

    OpenAIRE

    Mizuno, Shuntaro; Maeda, Kei-ichi; Yamamoto, Kohta

    2002-01-01

    We study the dynamics of a scalar field in the brane cosmology. We assume that a scalar field is confined in our 4-dimensional world. As for the potential of the scalar field, we discuss three typical models: (1) a power-law potential, (2) an inverse-power-law potential, and (3) an exponential potential. We show that the behavior of the scalar field is very different from a conventional cosmology when the energy density square term is dominated.

  19. Contact interactions in D-brane models

    CERN Document Server

    Antoniadis, Ignatios; Laugier, A.

    2001-01-01

    We compute the tree-level four-point scattering amplitudes in string models where matter fields live on D-brane intersections. Extracting the contribution of massless modes, we are left with dimension-six four-fermion operators which in general receive contributions from three different sources: exchange of massive Kaluza--Klein excitations, winding modes and string oscillator states. We compute their coefficients and extract new bounds on the string scale in the brane-world scenario. This is contrasted with the situation where matter fields arise from open strings with both ends confined on the same collection of D-branes, in which case the exchange of massive string modes leads to dimension-eight operators that have been studied in the past. When matter fields live on brane intersections, the presence of dimension-six operators increase the lower bound on the string scale to 1--2 TeV, independently of the number of large extra dimensions.

  20. D-brane Standard Model

    CERN Document Server

    Antoniadis, Ignatios; Tomaras, T N

    2001-01-01

    The minimal embedding of the Standard Model in type I string theory is described. The SU(3) color and SU(2) weak interactions arise from two different collections of branes. The correct prediction of the weak angle is obtained for a string scale of 6-8 TeV. Two Higgs doublets are necessary and proton stability is guaranteed. It predicts two massive vector bosons with masses at the TeV scale, as well as a new superweak interaction.

  1. 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.

  2. 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.

  3. Bounded scalar perturbations in bouncing brane world cosmologies

    Science.gov (United States)

    Maier, Rodrigo; Pace, Francesco; Soares, Ivano Damião

    2013-11-01

    We examine the dynamics of scalar perturbations in closed Friedmann-Lemaître-Robertson-Walker universes in the framework of brane world theory with a timelike extra dimension. In this scenario, the unperturbed Friedmann equations contain additional terms arising from the bulk-brane interaction that implement nonsingular bounces in the models with a cosmological constant and noninteracting perfect fluids. The structure of the phase space of the models allows for two basic configurations, namely, one bounce solutions and eternal universes. Assuming that the matter content of the model is given by dust and radiation, we derive the dynamical field equations for scalar hydrodynamical perturbations considering either a conformally flat (de Sitter) bulk or a perturbed bulk. The dynamical system built with these equations is extremely involved. Nevertheless, in this paper we perform a numerical analysis which can shed some light on the study of cosmological scalar perturbations in bouncing brane world models. From a mathematical point of view we show that although the bounce enhances the amplitudes of scalar perturbations for one bounce models in the case of a de Sitter bulk, the amplitudes of the perturbations remain sufficiently small and bounded relative to the background values up to a certain scale. For one bounce models in the case of a perturbed bulk the amplitudes of all perturbations (apart from the Weyl fluid energy density) remain sufficiently small and bounded relative to the background values for any scale of the perturbations. We also discuss and compare the stability and bounded behavior of the perturbations in the late accelerated phase of one bounce solutions. For eternal universes we argue that some of these features are maintained only for early times (typically of the order of the first bounce). In this sense we show that eternal solutions are highly unstable configurations considering the background model of this paper.

  4. Standard model on D-branes

    Indian Academy of Sciences (India)

    Abstract. I briefly outline previous work on getting the (supersymmetric) standard model from string theory, and then describe two ecent attempts using D-branes. The first uses D3- and D7- branes and gives a supersymmetric standard model with extra vector-like matter and an intermediate unification scale. The second uses ...

  5. Standard model on D-branes

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Abstract. I briefly outline previous work on getting the (supersymmetric) standard model from string theory, and then describe two ecent attempts using D-branes. The first uses D3- and D7- branes and gives a supersymmetric standard model with extra vector-like matter and an intermediate unification scale.

  6. Brane-world motion in compact dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Greene, Brian; Levin, Janna [Institute for Strings, Cosmology and Astroparticle Physics, Columbia University, New York, NY 10027 (United States); Parikh, Maulik, E-mail: maulik.parikh@asu.edu [Department of Physics and Beyond, Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ 85287 (United States)

    2011-08-07

    The topology of extra dimensions can break global Lorentz invariance, singling out a globally preferred frame even in flat spacetime. Through experiments that probe global topology, an observer can determine her state of motion with respect to the preferred frame. This scenario is realized if we live on a brane universe moving through a flat space with compact extra dimensions. We identify three experimental effects due to the motion of our universe that one could potentially detect using gravitational probes. One of these relates to the peculiar properties of the twin paradox in multiply-connected spacetimes. Another relies on the fact that the Kaluza-Klein modes of any bulk field are sensitive to boundary conditions. A third concerns the modification to the Newtonian potential on a moving brane. Remarkably, we find that even small extra dimensions are detectable by brane observers if the brane is moving sufficiently fast. Communicated by P R L V Moniz

  7. Brane-world motion in compact dimensions

    Science.gov (United States)

    Greene, Brian; Levin, Janna; Parikh, Maulik

    2011-08-01

    The topology of extra dimensions can break global Lorentz invariance, singling out a globally preferred frame even in flat spacetime. Through experiments that probe global topology, an observer can determine her state of motion with respect to the preferred frame. This scenario is realized if we live on a brane universe moving through a flat space with compact extra dimensions. We identify three experimental effects due to the motion of our universe that one could potentially detect using gravitational probes. One of these relates to the peculiar properties of the twin paradox in multiply-connected spacetimes. Another relies on the fact that the Kaluza-Klein modes of any bulk field are sensitive to boundary conditions. A third concerns the modification to the Newtonian potential on a moving brane. Remarkably, we find that even small extra dimensions are detectable by brane observers if the brane is moving sufficiently fast. Communicated by P R L V Moniz

  8. Stellar stability in brane-worlds revisited

    Science.gov (United States)

    García-Aspeitia, Miguel A.; Ureña-López, L. Arturo

    2015-01-01

    We consider here the general conditions for the stability of brane stars that obey a so called a minimal setup: the nonlocal anisotropic stress and energy flux are absent everywhere, and the only permitted Weyl correction is the interior solution of the nonlocal energy density. Along with a series of simple conditions, we show that the Germani-Maartens solution with a constant density sets up the upper bound for the compactness of that particular class of brane stars. The general demonstration is based upon the properties of the interior solutions of the stars, although we also show that the minimal setup implies a Schwarzschild exterior.

  9. Particle physics of brane worlds and extra dimensions

    CERN Document Server

    Raychaudhuri, Sreerup

    2016-01-01

    The possibility that we live in a higher-dimensional world with spatial dimensions greater than three started with the early work of Kaluza and Klein. However, in addressing experimental constraints, early model-builders were forced to compactify these extra dimensions to very tiny scales. With the development of brane-world scenarios it became possible to consider novel compactifications which allow the extra dimensions to be large or to provide observable effects of these dimensions at experimentally accessible energy scales. This book provides a comprehensive account of these recent developments, keeping the high-energy physics implications in focus. After an historical survey of the idea of extra dimensions, the book deals in detail with models of large extra dimensions, warped extra dimensions and other models such as universal extra dimensions. The theoretical and phenomenological implications are discussed in a pedagogical manner for both researchers and graduate students.

  10. Bulk renormalization and particle spectrum in codimension-two brane worlds

    Science.gov (United States)

    Salvio, Alberto

    2013-04-01

    We study the Casimir energy due to bulk loops of matter fields in codimension-two brane worlds and discuss how effective field theory methods allow us to use this result to renormalize the bulk and brane operators. In the calculation we explicitly sum over the Kaluza-Klein (KK) states with a new convenient method, which is based on a combined use of zeta function and dimensional regularization. Among the general class of models we consider we include a supersymmetric example, 6D gauged chiral supergravity. Although much of our discussion is more general, we treat in some detail a class of compactifications, where the extra dimensions parametrize a rugby ball shaped space with size stabilized by a bulk magnetic flux. The rugby ball geometry requires two branes, which can host the Standard Model fields and carry both tension and magnetic flux (of the bulk gauge field), the leading terms in a derivative expansion. The brane properties have an impact on the KK spectrum and therefore on the Casimir energy as well as on the renormalization of the brane operators. A very interesting feature is that when the two branes carry exactly the same amount of flux, one half of the bulk supersymmetries survives after the compactification, even if the brane tensions are large. We also discuss the implications of these calculations for the natural value of the cosmological constant when the bulk has two large extra dimensions and the bulk supersymmetry is partially preserved (or completely broken).

  11. Brane brick models in the mirror

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Sebastián [Physics Department, The City College of the CUNY,160 Convent Avenue, New York, NY 10031 (United States); The Graduate School and University Center, The City University of New York,365 Fifth Avenue, New York NY 10016 (United States); Lee, Sangmin [Center for Theoretical Physics, Seoul National University,Seoul 08826 (Korea, Republic of); Department of Physics and Astronomy, Seoul National University,Seoul 08826 (Korea, Republic of); College of Liberal Studies, Seoul National University,Seoul 08826 (Korea, Republic of); Seong, Rak-Kyeong [School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Vafa, Cumrun [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

    2017-02-21

    Brane brick models are Type IIA brane configurations that encode the 2dN=(0,2) gauge theories on the worldvolume of D1-branes probing toric Calabi-Yau 4-folds. We use mirror symmetry to improve our understanding of this correspondence and to provide a systematic approach for constructing brane brick models starting from geometry. The mirror configuration consists of D5-branes wrapping 4-spheres and the gauge theory is determined by how they intersect. We also explain how 2d(0,2) triality is realized in terms of geometric transitions in the mirror geometry. Mirror symmetry leads to a geometric unification of dualities in different dimensions, where the order of duality is n−1 for a Calabi-Yau n-fold. This makes us conjecture the existence of a quadrality symmetry in 0d. Finally, we comment on how the M-theory lift of brane brick models connects to the classification of 2d(0,2) theories in terms of 4-manifolds.

  12. 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.

  13. 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.

  14. On the localization of four-dimensional brane-world black holes

    Science.gov (United States)

    Kanti, P.; Pappas, N.; Zuleta, K.

    2013-12-01

    In the context of brane-world models, we pursue the question of the existence of five-dimensional solutions describing regular black holes localized close to the brane. Employing a perturbed Vaidya-type line-element embedded in a warped fifth dimension, we attempt to localize 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 those characterized by a high degree of flexibility, a negative result was reached. Our analysis demonstrates how difficult the analytic construction of a localized brane-world black hole may be in the context of a well-defined field-theory model. Finally, with regard to the question of the existence or not of a static classical black-hole solution on the brane, our analysis suggests that such solutions could in principle exist; however, the associated field configuration itself has to be dynamic.

  15. PRAMANA Black holes in brane worlds M s MODGIL, s PANDA and ...

    Indian Academy of Sciences (India)

    Black holes in brane worlds. M s MODGIL, s PANDA and G sENGUPTA. Department of Physics, Indian Institute of Technology, Kanpur 208 016, India. Abstract. A Kerr metric describing a rotating black hole is obtained on the three brane in a five-dimensional Randall-Sundrum brane world by considering a rotating five-.

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

    National Research Council Canada - National Science Library

    Herrera-Aguilar, A; Kuerten, A. M; da Rocha, Roldão

    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...

  17. Brane-world black holes with post-Newtonian parameter: astrophysical signatures

    Science.gov (United States)

    da Rocha, Roldão; Piloyan, Arpine

    2014-03-01

    The existence of the many unanswered questions in fundamental physics, in particular, in astrophysics allows for a great variety of theories to remain viable candidates for becoming the correct theory at energies not accessible in current experiments. One special class of these type of theories is the class of extra-dimensional brane-world models. Besides answering many fundamental problems, for instance, the hierarchy problem, they may produce testable predictions. In this work, we find and investigate brane-world induced black string horizon corrections, when the black hole solution has a post-Newtonian parameter. For suitable choices of such a parameter, the Hawking radiation on the brane is precluded, and the Hawking radiation in the bulk causes the black hole to slightly recoil into the bulk, which modifies the black hole apparent horizon. It has an impact on quasars luminosity and, therefore, might be detected and measured.

  18. Gravity and antigravity in a brane world with metastable gravitons

    Science.gov (United States)

    Gregory, R.; Rubakov, V. A.; Sibiryakov, S. M.

    2000-09-01

    In the framework of a five-dimensional three-brane model with quasi-localized gravitons we evaluate metric perturbations induced on the positive tension brane by matter residing thereon. We find that at intermediate distances, the effective four-dimensional theory coincides, up to small corrections, with General Relativity. This is in accord with Csaki, Erlich and Hollowood and in contrast to Dvali, Gabadadze and Porrati. We show, however, that at ultra-large distances this effective four-dimensional theory becomes dramatically different: conventional tensor gravity changes into scalar anti-gravity.

  19. On Supersymmetry Breaking in Intersecting Brane Models

    Energy Technology Data Exchange (ETDEWEB)

    Klein, M

    2004-01-13

    We discuss a framework to analyze the transmission of supersymmetry breaking in models of intersecting D-branes. Generically, different intersections preserve different fractions of an extended bulk supersymmetry, thus breaking supersymmetry completely but in a nonlocal way. We analyze this mechanism in a 5D toy model where two brane intersections, which are separated in the fifth dimension, break different halves of an extended {Nu} = 2 supersymmetry. The sector of the theory on one brane intersection feels the breakdown of the residual {Nu} = 1 supersymmetry only through two-loop interactions involving a coupling to fields from the other intersection. We compute the diagrams that contribute to scalar masses on one intersection and find that the masses are proportional to the compactification scale up to logarithmic corrections. We also compute the three-loop diagrams relevant to the Casimir energy between the two intersections and find a repulsive Casimir force.

  20. An Index for Intersecting Branes in Matrix Models

    Directory of Open Access Journals (Sweden)

    Harold Steinacker

    2013-11-01

    Full Text Available We introduce an index indicating the occurrence of chiral fermions at the intersection of branes in matrix models. This allows to discuss the stability of chiral fermions under perturbations of the branes.

  1. D-Brane superstrings and new perspective of our world

    CERN Document Server

    Hashimoto, Koji

    2012-01-01

    Superstring theory is a promising theory which can potentially unify all the forces and the matters in particle physics. A new multi-dimensional object which is called "D-brane" was found. It drastically changed our perspective of a unified world. We may live on membrane-like hypersurfaces in higher dimensions ("braneworld scenario"), or we can create blackholes at particle accelarators, or the dynamics of quarks is shown to be equivalent to the higher dimensional gravity theory. All these scenarios are explained in this book with plain words but with little use of equations and with many figures. The book starts with a summary of long-standing problems in elementary particle physics and explains the D-branes and many applications of them. It ends with future roads for a unified ultimate theory of our world.  

  2. The fate of Newton's law in brane-world scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Benichou, Raphael, E-mail: raphael.benichou@vub.ac.be [Theoretische Natuurkunde, Vrije Universiteit Brussel and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Estes, John, E-mail: johnaldonestes@gmail.com [Instituut voor Theoretische Fysica, KULeuven, Celestijnenlaan 200D B-3001 Leuven (Belgium)

    2012-06-12

    We consider brane-world scenarios embedded into string theory. We find that the D-brane backreaction induces a large increase in the open string's proper length. Consequently the stringy nature of elementary particles can be detected at distances much larger than the fundamental string scale. As an example, we compute the gravitational potential between two open strings ending on backreacting D3-branes in four-dimensional compactifications of type II string theory. We find that the Newtonian potential receives a correction that goes like 1/r but that is not proportional to the inertial masses of the open strings, implying a violation of the equivalence principle in the effective gravitational theory. This stringy correction is screened by thermal effects when the distance between the strings is greater than the inverse temperature. This suggests new experimental tests for many phenomenological models in type II string theory.

  3. Gravity in the randall-sundrum brane world

    Science.gov (United States)

    Garriga; Tanaka

    2000-03-27

    We discuss the weak gravitational field created by isolated matter sources in the Randall-Sundrum brane world. For the case of a single wall of positive tension, the field stays localized near the wall if the source is stationary. We calculate the leading Kaluza-Klein corrections to the linearized gravitational field of a nonrelativistic spherical object, which is different from the Schwarzschild solution at large distances. In the case of two branes of opposite tension, linearized Brans-Dicke (BD) gravity is recovered on either wall, with different BD parameters. On the wall with positive tension the BD parameter is larger than 3000 provided that the separation between walls is larger than 4 times the AdS radius. The gravitational field due to shadow matter is also considered.

  4. Quest for Localized 4-D Black Holes in Brane Worlds

    CERN Document Server

    Kanti, Panagiota; Kanti, Panagiota; Tamvakis, Kyriakos

    2002-01-01

    We investigate the possibility of obtaining localized black hole solutions in brane worlds by introducing a dependence of the four-dimensional line-element on the extra dimension. An analysis performed for the cases of an empty bulk and of a bulk containing either a scalar or a gauge field reveals that no conventional type of matter can support such a dependence. Considering a particular ansatz for the five-dimensional line-element that corresponds to a black hole solution with a ``decaying'' horizon, we determine the bulk energy-momentum tensor capable of sustaining such a behaviour. It turns out that an exotic, shell-like distribution of matter is required. For such solutions, the black hole singularity is indeed localized near the brane and the spacetime is well defined near the AdS horizon in contrast to the behaviour found in black string type solutions.

  5. Brane worlds theories with one or two extra dimensions

    CERN Document Server

    Salvio, Alberto

    2013-01-01

    This book is roughly divided in three parts. The first one is a general introduction to theories with extra dimensions and, more specifically, to brane worlds. Both old-fashioned topics (such as Kaluza-Klein theories) and more modern aspects (e.g. Large Extra Dimensions and Randall-Sundrum models) are discussed. The second and third parts (which we refer to as Part I and II respectively) are essentially two monographs. There, the reader is guided through the construction of the 4D effective field theory derived from higher dimensional (in particular five-dimensional and six-dimensional) models. Part I is devoted to the study of how the heavy Kaluza-Klein modes contribute to the low energy dynamics of the light modes. Part II concerns instead the analysis of the spectrum arising from non-standard compactifications of six-dimensional (supersymmetric) theories, involving a warp factor and conical defects in the internal manifold. Several applications of the above mentioned topics are discussed, providing an up t...

  6. On Realistic Brane Worlds from Type i Strings

    Science.gov (United States)

    Aldazabal, Gerardo; IbÁñez, Luis E.; Quevedo, Fernando

    We review recent progress in constructing realistic brane models from type I string vacua. Explicit models with three families of the standard model gauge group and its l-right generalizations are presented with supersymmetry broken at the string scale of order Ms ~ 1010-12 roman>GeVroman>, realizing gravity mediated supersymmetry breaking at low energies. Unification of couplings occurs at the string scale due to the particular U(1) normalizations of roman>Droman>-branes, as well as to the existence of a Higgs field per family of quarks and leptons. The proton is naturally stable due to intrinsic discrete symmetries of the corresponding string theory. In particular R-parity appears as a natural stringy symmetry. There are axionic fields with the right couplings as to solve the strong CP problem. Similar realizations are also presented for a string scale of 1 TeV, although without solving the gauge unification problem. Open questions are briefly discussed.

  7. Dynamical study of DBI-essence in loop quantum cosmology and brane world

    Science.gov (United States)

    Bhadra, Jhumpa; Debnath, Ujjal

    2012-08-01

    We have studied homogeneous isotropic FRW model having dynamical dark energy DBI-essence with scalar field. Existence of cosmological scaling solutions restricts the Lagrangian of the scalar field ϕ. Choosing p= Xg( Xe λϕ ), where X=- g μν ∂ μ ϕ∂ ν ϕ/2 with g any function of Xe λϕ and defining some suitable transformations, we have constructed the dynamical system in different models of gravity: (i) Loop Quantum Cosmology (LQC), (ii) DGP brane world and (iii) RS II brane world. We have investigated stability of this dynamical system around the critical point for three gravity models and investigated the scalar-field dominated attractor solution in support of accelerated universe. The roles of the physical parameters have also been shown graphically during the accelerating phase of the universe.

  8. World-volume effective action of exotic five-brane in M-theory

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Tetsuji [Research and Education Center for Natural Sciences, Keio University, Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521 (Japan); Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan); Sasaki, Shin [Department of Physics, Kitasato University,Sagamihara 252-0373 (Japan); Yata, Masaya [Department of Physics, National University of Singapore,2, Science Drive 3, Singapore 117542 (Singapore)

    2016-02-25

    We study the world-volume effective action of an exotic five-brane, known as the M-theory 5{sup 3}-brane (M5{sup 3}-brane) in eleven dimensions. The supermultiplet of the world-volume theory is the N=(2,0) tensor multiplet in six dimensions. The world-volume action contains three Killing vectors k̂{sub Î}{sup M} (Î=1,2,3) associated with the U(1){sup 3} isometry. We find the effective T-duality rule for the eleven-dimensional backgrounds that transforms the M5-brane effective action to that of the M5{sup 3}-brane. We also show that our action provides the source term for the M5{sup 3}-brane geometry in eleven-dimensional supergravity.

  9. Branes in the GL(1|1) WZNW-model

    NARCIS (Netherlands)

    Creutzig, T.; Quella, T.; Schomerus, V.

    2008-01-01

    We initiate a systematic study of boundary conditions in conformal field theories with target space supersymmetry. The WZNW model on GL(1|1) is used as a prototypical example for which we find the complete set of maximally symmetric branes. This includes a unique brane of maximal super-dimension

  10. Split supersymmetry in brane models

    Indian Academy of Sciences (India)

    Type-I string theory in the presence of internal magnetic fields provides a concrete realization of split supersymmetry. To lowest order, gauginos are massless while squarks and sleptons are superheavy. For weak magnetic fields, the correct Standard Model spectrum guarantees gauge coupling unification with sin2 W ...

  11. On some new warped brane world solutions in higher dimensions

    OpenAIRE

    Randjbar-Daemi, Seif; Shaposhnikov, Mikhail E

    2000-01-01

    We present new solutions of higher dimensional Einstein's equations with a cosmological constant that localize gravity on branes which are transverse to Ricci-flat manifolds or to homogeneous spaces with topologically non-trivial solutions of gauge field equations. These solutions are relevant for the localization of chiral fermions on a brane. (C) 2000 Published by Elsevier Science B.V.

  12. Massive branes

    NARCIS (Netherlands)

    Bergshoeff, E; Lozano, Y; Ortin, T

    1998-01-01

    We investigate the effective world-volume theories of branes in a background given by (the bosonic sector of) 10-dimensional massive IIA supergravity ("massive branes") and their M-theoretic origin. In the case of the solitonic 5-brane of type IIA superstring theory the construction of the

  13. 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.

  14. Bouncing Branes

    CERN Document Server

    Burgess, C P; Rabadan, Raul; Tasinato, G; Zavala, I

    2004-01-01

    We present several higher-dimensional spacetimes for which observers living on 3-branes experience an induced metric which bounces. The classes of examples include boundary branes on generalised S-brane backgrounds and probe branes in D-brane/anti D-brane systems. The bounces we consider normally would be expected to require an energy density which violates the weak energy condition, and for our co-dimension one examples this is attributable to bulk curvature terms in the effective Friedmann equation. We examine the features of the acceleration which provides the bounce, including in some cases the existence of positive acceleration without event horizons, and we give a geometrical interpretation for it. We discuss the stability of the solutions from the point of view of both the brane and the bulk. Some of our examples appear to be stable from the bulk point of view, suggesting the possible existence of stable bouncing cosmologies within the brane-world framework.

  15. Excited de Sitter brane worlds localized by a kink

    Science.gov (United States)

    Brihaye, Y.; Delsate, T.

    2012-07-01

    We reconsider, in five-dimensional space-time, the issue of thick brane localized in the extra dimension by a kink formed by a scalar field. The localization is achieved by a sine-Gordon potential. Apart from a fundamental brane (where the scalar field is a monotonic function of the extra dimension [R. Koley and S. Kar, Classical Quantum Gravity 22, 753 (2005)CQGRDG0264-938110.1088/0264-9381/22/4/008]), we show that a series of new solutions exist as well, labeled by the number of zeros of the scalar field. These solutions are regular, localized on the brane, and mirror-symmetric with respect to the extra dimension. They form a tower of “excited branes”. The study of some perturbations of the solutions reveals that the new solutions are not stable. Finally, fermions are coupled to the scalar field by means of a Yukawa potential and their localization in the background of the new solutions is examined. It turns out that the excited branes can localize left and right chiral fermions either on the brane and/or in the bulk but close to the brane.

  16. Stability of the graviton Bose–Einstein condensate in the brane-world

    Directory of Open Access Journals (Sweden)

    Roberto Casadio

    2016-12-01

    Full Text Available We consider a solution of the effective four-dimensional Einstein equations, obtained from the general relativistic Schwarzschild metric through the principle of Minimal Geometric Deformation (MGD. Since the brane tension can, in general, introduce new singularities on a relativistic Eötvös brane model in the MGD framework, we require the absence of observed singularities, in order to constrain the brane tension. We then study the corresponding Bose–Einstein condensate (BEC gravitational system and determine the critical stability region of BEC MGD stellar configurations. Finally, the critical stellar densities are shown to be related with critical points of the information entropy.

  17. Stability of the graviton Bose–Einstein condensate in the brane-world

    Energy Technology Data Exchange (ETDEWEB)

    Casadio, Roberto, E-mail: casadio@bo.infn.it [Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna, viale B. Pichat 6, 40127 Bologna (Italy); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [CMCC, Universidade Federal do ABC, 09210-580, Santo André, SP (Brazil)

    2016-12-10

    We consider a solution of the effective four-dimensional Einstein equations, obtained from the general relativistic Schwarzschild metric through the principle of Minimal Geometric Deformation (MGD). Since the brane tension can, in general, introduce new singularities on a relativistic Eötvös brane model in the MGD framework, we require the absence of observed singularities, in order to constrain the brane tension. We then study the corresponding Bose–Einstein condensate (BEC) gravitational system and determine the critical stability region of BEC MGD stellar configurations. Finally, the critical stellar densities are shown to be related with critical points of the information entropy.

  18. Stability of the graviton Bose-Einstein condensate in the brane-world

    Science.gov (United States)

    Casadio, Roberto; da Rocha, Roldão

    2016-12-01

    We consider a solution of the effective four-dimensional Einstein equations, obtained from the general relativistic Schwarzschild metric through the principle of Minimal Geometric Deformation (MGD). Since the brane tension can, in general, introduce new singularities on a relativistic Eötvös brane model in the MGD framework, we require the absence of observed singularities, in order to constrain the brane tension. We then study the corresponding Bose-Einstein condensate (BEC) gravitational system and determine the critical stability region of BEC MGD stellar configurations. Finally, the critical stellar densities are shown to be related with critical points of the information entropy.

  19. Anisotropic branes

    Science.gov (United States)

    Banerjee, Souvik; Bhowmick, Samrat; Mukherji, Sudipta

    2013-10-01

    We present a class of anisotropic brane configurations which shows BKL oscillations near their cosmological singularities. Near horizon limits of these solutions represent Kasner space embedded in AdS background. Dynamical probe branes in these geometries inherit anisotropies from the background. Amusingly, for a probe M5 brane, we find that there exists a parameter region where three of its world-volume directions expand while the rest contract.

  20. Micro-orbits in a many-brane model and deviations from Newton's 1/r^2 law

    Science.gov (United States)

    Donini, A.; Marimón, S. G.

    2016-12-01

    We consider a five-dimensional model with geometry M = M_4 × S_1, with compactification radius R. The Standard Model particles are localized on a brane located at y=0, with identical branes localized at different points in the extra dimension. Objects located on our brane can orbit around objects located on a brane at a distance d=y/R, with an orbit and a period significantly different from the standard Newtonian ones. We study the kinematical properties of the orbits, finding that it is possible to distinguish one motion from the other in a large region of the initial conditions parameter space. This is a warm-up to study if a SM-like mass distribution on one (or more) distant brane(s) may represent a possible dark matter candidate. After using the same technique to the study of orbits of objects lying on the same brane (d=0), we apply this method to the detection of generic deviations from the inverse-square Newton law. We propose a possible experimental setup to look for departures from Newtonian motion in the micro-world, finding that an order of magnitude improvement on present bounds can be attained at the 95% CL under reasonable assumptions.

  1. Quest for Localized 4-D Black Holes in Brane Worlds. II Removing the bulk singularities

    CERN Document Server

    Kanti, P.; Tamvakis, K.

    2003-01-01

    We analyze further the possibility of obtaining localized black hole solutions in the framework of Randall-Sundrum-type brane-world models. We consider black hole line-elements analytic at the horizon, namely, generalizations of the Painleve and Vaidya metrics, which are taken to have a decaying dependence of the horizon on the extra dimension. These backgrounds have no other singularities apart from the standard black hole singularity which is localized in the direction of the fifth dimension. Both line-elements can be sustained by a regular, shell-like distribution of bulk matter of a non-standard form. Of the two, the Vaidya line-element is shown to provide the most attractive, natural choice: despite the scaling of the horizon, the 5D spacetime has the same topological structure as the one of a RS-Schwarzschild spacetime and demands a minimal bulk energy-momentum tensor.

  2. Strings and brane world scenarios in financial market data

    Directory of Open Access Journals (Sweden)

    Richard Pincak

    2013-05-01

    Full Text Available In the paper, we study the projections of the real exchange rate dynamics onto the string-like topology. Our approach is inspired by the contemporary movements in the string theory. The string map of data is defined here by the boundary conditions, characteristic length, real valued and the method of redistribution of information. As a practical matter, this map represents the detrending and data standardization procedure. We introduced maps onto 1-end-point and 2-end-point open strings that satisfy the Dirichlet and Neumann boundary conditions. The questions of the choice of extra-dimensions, symmetries, duality and ways to the partial compactification are discussed. Subsequently, we pass to higher dimensional and more complex objects. The 2D-Brane was suggested which incorporated bid-ask spreads. The systematic way which allows one suggest more structured maps suitable for a simultaneous study of several currency pairs was analyzed by means of the Gâteaux generalized differential calculus. The effect of the string and brane maps on test data was studied by comparing their mean statistical characteristics. The possible utilizations of the string theory approach in financial market are slight.

  3. An investigation of equivalence between the bulk-based and the brane-based approaches for anisotropic models

    Science.gov (United States)

    Uluyazı, Gülçin

    2012-04-01

    We investigate the relation between the brane-based and the bulk-based approaches for anisotropic case in brane-world models. In the brane-based approach, the brane is chosen to be fixed on a coordinate system, whereas in the bulk-based approach it is no longer static as it moves along the extra dimension. It was shown that these two approaches are equivalent for specific models in Mukohyama et al. (Phys Rev D 62:024028, 2000), Bowcock et al. (Class Quant Gravit 17:4745-4764, 2000). In this paper, it is aimed to get general formalism of the equivalence obtained in Mukohyama et al. (Phys Rev D 62:024028, 2000). We found that calculations driven by a general anisotropic bulk-based metric yield a brane-based metric in Gaussian Normal Coordinates by conserving spatial anisotropy. We also derive solutions for an anisotropic bulk-based model and get the corresponding brane-based metric of the model.

  4. T-branes as branes within branes

    Energy Technology Data Exchange (ETDEWEB)

    Collinucci, Andrés [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Bruxelles (Belgium); Savelli, Raffaele [Institut de Physique Théorique, CEA Saclay,Orme de Merisiers, F-91191 Gif-surYvette (France)

    2015-09-23

    Bound states of 7-branes known as ‘T-branes’ have properties that defy usual geometric intuition. For instance, the gauge group of n coincident branes may not be U(n). More surprisingly, matter may show up at unexpected loci, such as points. By analyzing T-branes of perturbative type IIB string theory in the tachyon condensation picture we gain the following insights: in a large class of models, the tachyon can be diagonalized even though the worldvolume Higgs cannot. In those cases, we see the structure of these bound states more manifestly, thereby drastically simplifying analysis of gauge groups and spectra. Whenever the tachyon is not diagonalizable, matter localizes at unexpected loci, and we find that there is a lower-dimensional brane bound to the 7-brane.

  5. Fluxbranes from p-branes

    OpenAIRE

    Saffin, P. M.

    2001-01-01

    It is shown how magnetic fluxbrane, Fp-brane, solutions are related to electric black p-branes by analytic continuation. Viewing the transverse space of branes as a warped cone, one finds that the cone base of the p-brane becomes the world-volume of the F(D-p-3)-brane and the world volume of the p-brane becomes the cone base of the F(D-p-3)-brane. An explicit example of the correspondence is given for a 2-brane and F6-brane of 11D supergravity.

  6. 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.

  7. Dynamics of interacting generalized cosmic Chaplygin gas in brane-world scenario

    Science.gov (United States)

    Rudra, Prabir

    2012-12-01

    In this work we explore the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by brane cosmology. Here DGP and the RSII brane models have been considered separately. Dark energy in the form of Generalized Cosmic Chaplygin gas is considered. A suitable interaction between dark energy and dark matter is considered in order to at least alleviate (if not solve) the cosmic coincidence problem. The dynamical system of equations is solved numerically and a stable scaling solution is obtained. A significant attempt towards the solution of the cosmic coincidence problem is taken. The statefinder parameters are also calculated to classify the dark energy models. Graphs and phase diagrams are drawn to study the variations of these parameters. It is also seen that the background dynamics of Generalized Cosmic Chaplygin gas is consistent with the late cosmic acceleration, but not without satisfying certain conditions. It has been shown that the universe in both the models follows the power law form of expansion around the critical point, which is consistent with the known results. Future singularities were studied and our models were declared totally free from any types of such singularities. Finally, some cosmographic parameters were also briefly studied. Our investigation led to the fact that although Generalized cosmic Chaplygin gas with a far lesser negative pressure compared to other dark energy models, can overcome the relatively weaker gravity of RS II brane, with the help of the negative brane tension, yet for the DGP brane model with much higher gravitation, the incompetency of Generalized cosmic Chaplygin gas is exposed, and it cannot produce the accelerating scenario until it reaches the phantom era.

  8. Semi-doubled sigma models for five-branes

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Tetsuji [Research and Education Center for Natural Sciences, Keio University,Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521 (Japan); Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan)

    2016-02-01

    We study two-dimensional N=(2,2) gauge theory and its dualized system in terms of complex (linear) superfields and their alternatives. Although this technique itself is not new, we can obtain a new model, the so-called “semi-doubled” GLSM. Similar to doubled sigma model, this involves both the original and dual degrees of freedom simultaneously, whilst the latter only contribute to the system via topological interactions. Applying this to the N=(4,4) GLSM for H-monopoles, i.e., smeared NS5-branes, we obtain its T-dualized systems in quite an easy way. As a bonus, we also obtain the semi-doubled GLSM for an exotic 5{sub 2}{sup 3}-brane whose background is locally nongeometric. In the low energy limit, we construct the semi-doubled NLSM which also generates the conventional string worldsheet sigma models. In the case of the NLSM for 5{sub 2}{sup 3}-brane, however, we find that the Dirac monopole equation does not make sense any more because the physical information is absorbed into the divergent part via the smearing procedure. This is nothing but the signal which indicates that the nongeometric feature emerges in the considering model.

  9. Gravity localization on hybrid branes

    Directory of Open Access Journals (Sweden)

    D.F.S. Veras

    2016-03-01

    Full Text Available This work deals with gravity localization on codimension-1 brane worlds engendered by compacton-like kinks, the so-called hybrid branes. In such scenarios, the thin brane behavior is manifested when the extra dimension is outside the compact domain, where the energy density is non-trivial, instead of asymptotically as in the usual thick brane models. The zero mode is trapped in the brane, as required. The massive modes, although not localized in the brane, have important phenomenological implications such as corrections to the Newton's law. We study such corrections in the usual thick domain wall and in the hybrid brane scenarios. By means of suitable numerical methods, we attain the mass spectrum for the graviton and the corresponding wavefunctions. The spectra possess the usual linearly increasing behavior from the Kaluza–Klein theories. Further, we show that the 4D gravitational force is slightly increased at short distances. The first eigenstate contributes highly for the correction to the Newton's law. The subsequent normalized solutions have diminishing contributions. Moreover, we find out that the phenomenology of the hybrid brane is not different from the usual thick domain wall. The use of numerical techniques for solving the equations of the massive modes is useful for matching possible phenomenological measurements in the gravitational law as a probe to warped extra dimensions.

  10. Gravity localization on hybrid branes

    Energy Technology Data Exchange (ETDEWEB)

    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); 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 [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)

    2016-03-10

    This work deals with gravity localization on codimension-1 brane worlds engendered by compacton-like kinks, the so-called hybrid branes. In such scenarios, the thin brane behavior is manifested when the extra dimension is outside the compact domain, where the energy density is non-trivial, instead of asymptotically as in the usual thick brane models. The zero mode is trapped in the brane, as required. The massive modes, although not localized in the brane, have important phenomenological implications such as corrections to the Newton's law. We study such corrections in the usual thick domain wall and in the hybrid brane scenarios. By means of suitable numerical methods, we attain the mass spectrum for the graviton and the corresponding wavefunctions. The spectra possess the usual linearly increasing behavior from the Kaluza–Klein theories. Further, we show that the 4D gravitational force is slightly increased at short distances. The first eigenstate contributes highly for the correction to the Newton's law. The subsequent normalized solutions have diminishing contributions. Moreover, we find out that the phenomenology of the hybrid brane is not different from the usual thick domain wall. The use of numerical techniques for solving the equations of the massive modes is useful for matching possible phenomenological measurements in the gravitational law as a probe to warped extra dimensions.

  11. Gravity localization on hybrid branes

    Science.gov (United States)

    Veras, D. F. S.; Cruz, W. T.; Maluf, R. V.; Almeida, C. A. S.

    2016-03-01

    This work deals with gravity localization on codimension-1 brane worlds engendered by compacton-like kinks, the so-called hybrid branes. In such scenarios, the thin brane behavior is manifested when the extra dimension is outside the compact domain, where the energy density is non-trivial, instead of asymptotically as in the usual thick brane models. The zero mode is trapped in the brane, as required. The massive modes, although not localized in the brane, have important phenomenological implications such as corrections to the Newton's law. We study such corrections in the usual thick domain wall and in the hybrid brane scenarios. By means of suitable numerical methods, we attain the mass spectrum for the graviton and the corresponding wavefunctions. The spectra possess the usual linearly increasing behavior from the Kaluza-Klein theories. Further, we show that the 4D gravitational force is slightly increased at short distances. The first eigenstate contributes highly for the correction to the Newton's law. The subsequent normalized solutions have diminishing contributions. Moreover, we find out that the phenomenology of the hybrid brane is not different from the usual thick domain wall. The use of numerical techniques for solving the equations of the massive modes is useful for matching possible phenomenological measurements in the gravitational law as a probe to warped extra dimensions.

  12. Equation-of-state formalism for dark energy models on the brane and the future of brane universes

    Energy Technology Data Exchange (ETDEWEB)

    Astashenok, Artyom V.; Yurov, Artyom V. [Baltic Federal University of I. Kant, Department of Theoretical Physics, Kaliningrad (Russian Federation); Elizalde, Emilio [Facultat de Ciencies, Consejo Superior de Investigaciones Cientificas, ICE/CSIC and IEEC Campus UAB, Bellaterra, Barcelona (Spain); Odintsov, Sergei D. [Facultat de Ciencies, Consejo Superior de Investigaciones Cientificas, ICE/CSIC and IEEC Campus UAB, Bellaterra, Barcelona (Spain); Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona (Spain)

    2012-12-15

    Brane dark energy cosmologies, leading to various possible evolutions of our universe, are investigated. The discussion shows that while all these models can be made arbitrarily close to the standard {Lambda}CDM cosmology at present, their future evolutions can be very different, even diverge with time in a number of ways. This includes asymptotic de-Sitter evolution, Little Rip with dissolution of bound structures, and various possible singularities, as the Big Rip, a sudden future singularity (Type II), and Type III and Type IV cases. Specifically, some interesting effects coming from the brane tension are investigated. It is shown, in particular, that the Little Rip occurs faster on the brane model than in usual FRW cosmology. In the asymptotic de-Sitter regime the influence of the brane tension leads to a deviation of the value of the effective cosmological constant from that corresponding to ordinary dark energy. As a consequence, the value of the inertial force from the accelerating expansion can greatly exceed the corresponding inertial force in ordinary cosmological models. (orig.)

  13. Thick brane models in generalized theories of gravity

    Directory of Open Access Journals (Sweden)

    D. Bazeia

    2015-04-01

    Full Text Available This work deals with thick braneworld models, in an environment where the Ricci scalar is changed to accommodate the addition of two extra terms, one depending on the Ricci scalar itself, and the other, which takes into account the trace of the energy–momentum tensor of the scalar field that sources the braneworld scenario. We suppose that the scalar field engenders standard kinematics, and we show explicitly that the gravity sector of this new braneworld scenario is linearly stable. We illustrate the general results investigating two distinct models, focusing on how the brane profile is changed in the modified theories.

  14. Cosmological evolution in a two-brane warped geometry model

    Directory of Open Access Journals (Sweden)

    Sumit Kumar

    2015-07-01

    Full Text Available We study an effective 4-dimensional scalar–tensor field theory, originated from an underlying brane–bulk warped geometry, to explore the scenario of inflation. It is shown that the inflaton potential naturally emerges from the radion energy–momentum tensor which in turn results in an inflationary model of the Universe on the visible brane that is consistent with the recent results from the Planck's experiment. The dynamics of modulus stabilization from the inflaton rolling condition is demonstrated. The implications of our results in the context of recent BICEP2 results are also discussed.

  15. Configurational entropy in f(R,T) brane models

    Energy Technology Data Exchange (ETDEWEB)

    Correa, R.A.C. [Universidade Federal do ABC, CCNH, Santo Andre, Sao Paulo (Brazil); Moraes, P.H.R.S. [ITA, Instituto Tecnologico de Aeronautica, Sao Jose dos Campos, Sao Paulo (Brazil)

    2016-02-15

    In this work we investigate generalized theories of gravity in the so-called configurational entropy (CE) context. We show, by means of this information-theoretical measure, that a stricter bound on the parameter of f(R, T) brane models arises from the CE. We find that these bounds are characterized by a valley region in the CE profile, where the entropy is minimal. We argue that the CE measure can play a new role and might be an important additional approach to selecting parameters in modified theories of gravitation. (orig.)

  16. Micro-orbits in a many-brane model and deviations from Newton's 1/r{sup 2} law

    Energy Technology Data Exchange (ETDEWEB)

    Donini, A.; Marimon, S.G. [CSIC-Universitat de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain)

    2016-12-15

    We consider a five-dimensional model with geometry M = M{sub 4} x S{sub 1}, with compactification radius R. The Standard Model particles are localized on a brane located at y = 0, with identical branes localized at different points in the extra dimension. Objects located on our brane can orbit around objects located on a brane at a distance d = y/R, with an orbit and a period significantly different from the standard Newtonian ones. We study the kinematical properties of the orbits, finding that it is possible to distinguish one motion from the other in a large region of the initial conditions parameter space. This is a warm-up to study if a SM-like mass distribution on one (or more) distant brane(s) may represent a possible dark matter candidate. After using the same technique to the study of orbits of objects lying on the same brane (d = 0), we apply this method to the detection of generic deviations from the inverse-square Newton law. We propose a possible experimental setup to look for departures from Newtonian motion in the micro-world, finding that an order of magnitude improvement on present bounds can be attained at the 95% CL under reasonable assumptions. (orig.)

  17. Domain walls in noncommutative gauge theories, folded D-branes, and communication with mirror world

    CERN Document Server

    Dubovsky, S.L.

    2004-01-01

    Noncommutative U(N) gauge theories at different N may be often thought of as different sectors of a single theory. For instance, U(1) theory possesses a sequence of vacua labeled by an integer parameter N, and the theory in the vicinity of the N-th vacuum coincides with the U(N) noncommutative gauge theory. We construct domain walls on noncommutative plane, which separate vacua with different gauge groups in gauge theory with adjoint scalar field. The scalar field has nonminimal coupling to the gauge field, such that the scale of noncommutativity is determined by the vacuum value of the scalar field. The domain walls are solutions of the BPS equations in the theory. It is natural to interprete the domain wall as a stack of D-branes plus a stack of folded D-branes. We support this interpretation by the analysis of small fluctuations around domain walls, and suggest that such configurations of branes emerge as solutions of the Matrix model in large class of pp-wave backgrounds with inhomogeneous field strength....

  18. Q-branes

    Science.gov (United States)

    Abel, Steven; Kehagias, Alex

    2015-11-01

    Non-topological solitons (Q-balls) are discussed in some stringy settings. Our main result is that the dielectric D-brane system of Myers admits non-abelian Q-ball solutions on their world-volume, in which N D p-branes relax to the standard dielectric form outside the Q-ball, but assume a more diffuse configuration at its centre. We also consider how Q-balls behave in the bulk of extra-dimensional theories, or on wrapped branes. We demonstrate that they carry Kaluza-Klein charge and possess a corresponding Kaluza-Klein tower of states just as normal particles, and we discuss surface energy effects by finding exact Q-ball solutions in models with a specific logarithmic potential.

  19. Cosmological constraints for a two brane-world system with single equation of state

    CERN Document Server

    Perez, Juan L; Urena-Lopez, L Arturo; 10.1063/1.3647549

    2012-01-01

    We present the study of two 3-brane system embedded in a 5-dimensional space-time in which the fifth dimension is compactified on a $S^{1}/Z_{2}$ orbifold. Assuming isotropic, homogeneous, and static branes, it can be shown that the dynamics of one brane is dominated by the other one when the metric coefficients have a particular form. We study the resulting cosmologies when one brane is dominated by a given single-fluid component.

  20. D-brane effective action and tachyon condensation in topological minimal models

    CERN Document Server

    Herbst, Manfred; Lerche, Wolfgang; Herbst, Manfred; Lazaroiu, Calin-Iuliu; Lerche, Wolfgang

    2005-01-01

    We study D-brane moduli spaces and tachyon condensation in B-type topological minimal models and their massive deformations. We show that any B-type brane is isomorphic with a direct sum of `minimal' branes, and that its moduli space is stratified according to the type of such decompositions. Using the Landau-Ginzburg formulation, we propose a closed formula for the effective deformation potential, defined as the generating function of tree-level open string amplitudes in the presence of D-branes. This provides a direct link to the categorical description, and can be formulated in terms of holomorphic matrix models. We also check that the critical locus of this potential reproduces the D-branes' moduli space as expected from general considerations. Using these tools, we perform a detailed analysis of a few examples, for which we obtain a complete algebro-geometric description of moduli spaces and strata.

  1. D-brane probes in the matrix model

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Frank, E-mail: frank.ferrari@ulb.ac.be

    2014-03-15

    Recently, a new approach to large N gauge theories, based on a generalization of the concept of D-brane probes to any gauge field theory, was proposed. In the present note, we compute the probe action in the one matrix model with a quartic potential. This allows to illustrate several non-trivial aspects of the construction in an exactly solvable set-up. One of our main goal is to test the bare bubble approximation. The approximate free energy found in this approximation, which can be derived from a back-of-an-envelope calculation, matches the exact result for all values of the 't Hooft coupling with a surprising accuracy. Another goal is to illustrate the remarkable properties of the equivariant partial gauge-fixing procedure, which is at the heart of the formalism. For this we use a general ξ-gauge to compute the brane action. The action depends on ξ in a very non-trivial way, yet we show explicitly that its critical value does not and coincides with twice the free energy, as required by general consistency. This is made possible by a phenomenon of ghost condensation and the spontaneous breaking of the equivariant BRST symmetry.

  2. Localization of Massive and Massless Fermions on Two-Field Branes

    Directory of Open Access Journals (Sweden)

    Ali Farokhtabar

    2017-01-01

    Full Text Available We study fermion localization and resonances on a special type of brane-world model supporting brane splitting. In such models one can construct multiwall branes which cause considerable simplification in the field equations. We use a polynomial superpotential to construct this brane. The suitable Yukawa coupling between the background scalar field and the localized fermion is determined. The massive fermion resonance spectrum is obtained. The number of resonances is increased for higher values of Yukawa coupling.

  3. Brane-Localized Gravity

    CERN Document Server

    Mannheim, Philip D

    2005-01-01

    This timely and valuable book provides a detailed pedagogical introduction and treatment of the brane-localized gravity program of Randall and Sundrum, in which gravitational signals are able to localize around our four-dimensional world in the event that it is a brane embedded in an infinitely-sized, higher dimensional anti-de Sitter bulk space. A completely self-contained development of the material needed for brane-world studies is provided for both students and workers in the field, with a significant amount of the material being previously unpublished. Particular attention is given to issues not ordinarily treated in the brane-world literature, such as the completeness of tensor gravitational fluctuation modes, the causality of brane-world propagators, and the status of the massless graviton fluctuation mode in brane worlds in which it is not normalizable.

  4. Model Kosmologi Brane dengan Parameter Perlambatan Ekspansi yang Gayut Linear terhadap Waktu

    Directory of Open Access Journals (Sweden)

    Azrul Azwar

    2012-05-01

    Full Text Available Telah dibangun model kosmologi brane dengan parameter perlambatan ekspansi yang gayut linear terhadap waktu. Dalam model ini telah diturunkan persaman untuk evolusi faktor skala, parameter Hubble, kerapatan materi-energi dan tekanan alam semesta.  Pada limit energi rendah seperti pada era alam semesta sekarang ini, yaitu pada saat rapat materi-energi jauh lebih kecil dibandingkan dengan tegangan brane, model yang di bangun ini akan kembali ke model Akarsu-Dereli.

  5. Dynamics of modified Chaplygin gas in brane world scenario: phase plane analysis

    Science.gov (United States)

    Rudra, Prabir; Debnath, Ujjal; Biswas, Ritabrata

    2012-05-01

    In this work we investigate the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by brane cosmology. Here DGP and the RSII brane models have been considered separately. Dark energy in the form of modified Chaplygin gas is considered. A suitable interaction between dark energy and dark matter is considered in order to at least alleviate (if not solve) the cosmic coincidence problem. The dynamical system of equations is solved numerically and a stable scaling solution is obtained. A significant attempt towards the solution of the cosmic coincidence problem is taken. The statefinder parameters are also calculated to classify the dark energy models. Graphs and phase diagrams are drawn to study the variations of these parameters. It is also seen that the background dynamics of modified Chaplygin gas is completely consistent with the notion of an accelerated expansion in the late universe. Finally, it has been shown that the universe in both the models follows the power law form of expansion around the critical point, which is consistent with the known results.

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

    Science.gov (United States)

    Olmo, Gonzalo J.; Rubiera-Garcia, D.

    2015-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Gonzalo J. Olmo

    2015-01-01

    Full Text Available 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.

  8. 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.

  9. D7-brane dynamics and thermalization in the Kuperstein–Sonnenschein model

    Energy Technology Data Exchange (ETDEWEB)

    Kaviani, Dariush, E-mail: dariush@ipm.ir

    2017-06-15

    We study the temperature of rotating probe D7-branes, dual to the temperature of flavored quarks, in the Kuperstein–Sonnenschein holographic model including the effects of spontaneous breakdown of the conformal and chiral flavor symmetry. The model embeds probe D7-branes into the Klebanov–Witten gravity dual of conformal gauge theory, with the embedding parameter, given by the minimal radial extension of the probe, setting the IR scale of conformal and chiral flavor symmetry breakdown. We show that when the minimal extension is positive definite and additional spin is turned on, the induced world volume metrics on the probe admit thermal horizons and Hawking temperatures despite the absence of black holes in the bulk. We find the scale and behavior of the temperature in flavored quarks are controlled dramatically by the IR scale of symmetry breaking, and by the strength and sort of external fields. We also derive the energy-stress tensor of the rotating probe and study its backreaction and energy dissipation. We show that at the IR scale the backreaction is nonnegligible and find the energy can flow from the probe to the bulk, dual to the energy dissipation from the flavor sector into the gauge theory.

  10. D7-brane dynamics and thermalization in the Kuperstein–Sonnenschein model

    Directory of Open Access Journals (Sweden)

    Dariush Kaviani

    2017-06-01

    Full Text Available We study the temperature of rotating probe D7-branes, dual to the temperature of flavored quarks, in the Kuperstein–Sonnenschein holographic model including the effects of spontaneous breakdown of the conformal and chiral flavor symmetry. The model embeds probe D7-branes into the Klebanov–Witten gravity dual of conformal gauge theory, with the embedding parameter, given by the minimal radial extension of the probe, setting the IR scale of conformal and chiral flavor symmetry breakdown. We show that when the minimal extension is positive definite and additional spin is turned on, the induced world volume metrics on the probe admit thermal horizons and Hawking temperatures despite the absence of black holes in the bulk. We find the scale and behavior of the temperature in flavored quarks are controlled dramatically by the IR scale of symmetry breaking, and by the strength and sort of external fields. We also derive the energy-stress tensor of the rotating probe and study its backreaction and energy dissipation. We show that at the IR scale the backreaction is nonnegligible and find the energy can flow from the probe to the bulk, dual to the energy dissipation from the flavor sector into the gauge theory.

  11. Massless and massive graviton spectra in anisotropic dilatonic brane-world cosmologies

    CERN Document Server

    De Risi, G

    2006-01-01

    We consider a braneworld model in which an anisotropic brane is embedded in a dilatonic background. We solve the background solutions and study the behavior of the perturbations when the universe evolves from an inflationary Kasner phase to a Minkowski phase. We calculate the massless mode spectrum, and find that it does not differ from what expected in standard four-dimensional cosmological models. We then evaluate the spectrum of both light (ultrarelativistic) and heavy (nonrelativistic) massive modes, and find that, at high energies, there can be a strong enhancement of the Kaluza-Klein spectral amplitude, which can become dominant in the total spectrum. The presence of the dilaton, on the contrary, decrease the relative importance of the massive modes.

  12. Defect branes

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Ortin, Tomas; Riccioni, Fabio

    2012-01-01

    We discuss some general properties of "defect branes", i.e. branes of co-dimension two, in (toroidally compactified) IIA/IIB string theory. In particular, we give a full classification of the supersymmetric defect branes in dimensions 3

  13. From the currency rate quotations onto strings and brane world scenarios

    Science.gov (United States)

    Horváth, D.; Pincak, R.

    2012-11-01

    In the paper, we study the projections of the real exchange rate dynamics onto the string-like topology. Our approach is inspired by the contemporary movements in the string theory. The string map of data is defined here by the boundary conditions, characteristic length, real valued and the method of redistribution of information. As a practical matter, this map represents the detrending and data standardization procedure. We introduced maps onto 1-end-point and 2-end-point open strings that satisfy the Dirichlet and Neumann boundary conditions. The questions of the choice of extra-dimensions, symmetries, duality and ways to the partial compactification are discussed. Subsequently, we pass to higher dimensional and more complex objects. The 2D-Brane was suggested which incorporated bid-ask spreads. Polarization by the spread was considered which admitted analyzing arbitrage opportunities on the market where transaction costs are taken into account. The model of the rotating string which naturally yields calculation of angular momentum is suitable for tracking of several currency pairs. The systematic way which allows one suggest more structured maps suitable for a simultaneous study of several currency pairs was analyzed by means of the Gâteaux generalized differential calculus. The effect of the string and brane maps on test data was studied by comparing their mean statistical characteristics. The study revealed notable differences between topologies. We review the dependence on the characteristic string length, mean fluctuations and properties of the intra-string statistics. The study explores the coupling of the string amplitude and volatility. The possible utilizations of the string theory approach in financial markets are slight.

  14. Spacelike brane actions.

    Science.gov (United States)

    Hashimoto, Koji; Ho, Pei-Ming; Wang, John E

    2003-04-11

    We derive effective actions for "spacelike branes" (S-branes) and find a solution describing the formation of fundamental strings in the rolling tachyon background. The S-brane action is a Dirac-Born-Infeld action for Euclidean world volumes defined in the context of time-dependent tachyon condensation of non-BPS (Bogomol'nyi-Prasad-Sommerfield) branes. It includes gauge fields and, in particular, a scalar field associated with translation along the time direction. We show that the BIon spike solutions constructed in this system correspond to the production of a confined electric flux tube (a fundamental string) at late time of the rolling tachyon.

  15. Crossing w=1 in Gauss-Bonnet Brane World with Induced Gravity

    National Research Council Canada - National Science Library

    CAI Rong-Gen ZHANG Hong-Sheng WANG An-Zhong

    2005-01-01

    .... In this paper we show that it is possible to realize such a crossing without introducing any phantom component in a Gauss-Bonnet brane worm with induced gravity, where a four-dimensional curvature...

  16. Stable, Time-Dependent, Exact Solutions for Brane Models with a Bulk Scalar Field

    CERN Document Server

    Lee, S; Olive, Keith A; Kanti, Panagiota; Lee, Seokcheon; Olive, Keith A.

    2003-01-01

    We derive two classes of brane-world solutions arising in the presence of a bulk scalar field. For static field configurations, we adopt a time-dependent, factorizable metric ansatz that allows for radion stabilization. The solutions are characterized by a non-trivial warping along the extra dimension, even in the case of a vanishing bulk cosmological constant, and lead to a variety of inflationary, time-dependent solutions of the 3D scale factor on the brane. We also derive the constraints necessary for the stability of these solutions under time-dependent perturbations of the radion field, and we demonstrate the existence of phenomenologically interesting, stable solutions with a positive cosmological constant on the brane.

  17. Space-time-filling branes and strings with sixteen supercharges

    NARCIS (Netherlands)

    Bergshoeff, E; Eyras, E; Halbersma, R; van der Schaar, JP; Hull, CM; Lozano, Y

    2000-01-01

    We discuss branes whose world-volume dimension equals the target space-time dimension, i.e. "space-time-filling branes". In addition to the D9-branes, there are 9-branes in the NS-NS sectors of both the IIA and IIB strings. The world-volume actions of these branes are constructed, via duality, from

  18. Branes in supergorups

    Energy Technology Data Exchange (ETDEWEB)

    Creutzig, Thomas

    2009-06-15

    In this thesis we initiate a systematic study of branes in Wess-Zumino-Novikov-Witten models with Lie supergroup target space. We start by showing that a branes' worldvolume is a twisted superconjugacy class and construct the action of the boundary WZNW model. Then we consider symplectic fermions and give a complete description of boundary states including twisted sectors. Further we show that the GL(1 vertical stroke 1) WZNW model is equivalent to symplectic fermions plus two scalars. We then consider the GL(1 vertical stroke 1) boundary theory. Twisted and untwisted Cardy boundary states are constructed explicitly and their amplitudes are computed. In the twisted case we find a perturbative formulation of the model. For this purpose the introduction of an additional fermionic boundary degree of freedom is necessary. We compute all bulk one-point functions, bulk-boundary two-point functions and boundary three-point functions. Logarithmic singularities appear in bulk-boundary as well as pure boundary correlation functions. Finally we turn to world-sheet and target space supersymmetric models. There is N=2 superconformal symmetry in many supercosets and also in certain supergroups. In the supergroup case we find some branes that preserve the topological A-twist and some that preserve the B-twist. (orig.)

  19. Multibrane DGP model: Our universe as a stack of (2+1)-dimensional branes

    Science.gov (United States)

    Dai, De-Chang; Stojkovic, Dejan; Wang, Bin; Zhang, Cheng-Yong

    2014-09-01

    We consider a scenario in which our (3+1)-dim universe is actually a dense stack of multiple parallel (2+1)-dim branes. For this purpose, we generalize the Dvali-Gabadadze-Porrati model to a multibrane case. We solve for the propagation of the scalar field and gravity in this setup. At short distances (high momenta) along the branes interactions follow the (2+1)-dim laws, while at large distances (low momenta) interactions follow the usual (3+1)-dim laws. This feature is inherited from the original Dvali-Gabadadze-Porrati model. In the direction perpendicular to the brane, we show that interactions become (3+1)-dim at low momenta which are unable to resolve the interbrane separation. Thus, this is one of the explicit constructs of the "vanishing dimensions" scenario where high energy physics appears to be lower dimensional rather than higher dimensional.

  20. Multiresonance modes in sine–Gordon brane models

    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 [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Fortaleza - CE, C.P. 6030, 60455-760 (Brazil); Dantas, D.M., E-mail: davi@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Fortaleza - CE, C.P. 6030, 60455-760 (Brazil); Almeida, C.A.S., E-mail: carlos@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Fortaleza - CE, C.P. 6030, 60455-760 (Brazil)

    2016-12-15

    In this work, we study the localization of the vector gauge field in two five-dimensional braneworlds generated by scalar fields coupled to gravity. The sine–Gordon like potentials are employed to produce different thick brane setups. A zero mode localized is obtained, and we show the existence of reverberations with the wave solutions indicating a quasi-localized massive mode. More interesting results are achieved when we propose a double sine–Gordon potential to the scalar field. The resulting thick brane shows a more detailed topology with the presence of an internal structure composed by two kinks. The massive spectrum of the gauge field is revalued on this scenario revealing the existence of various resonant modes. Furthermore, we compute the corrections to Coulomb law coming from these massive KK vector modes in these thick scenarios, which is concluded that the dilaton parameter regulates these corrections.

  1. Holomorphic variables in magnetized brane models with continuous Wilson lines

    CERN Document Server

    Camara, Pablo G; Dudas, Emilian

    2010-01-01

    We analyze the action of the target-space modular group in toroidal type IIB orientifold compactifications with magnetized D-branes and continuous Wilson lines. The transformation of matter fields agree with that of twisted fields in heterotic compactifications, constituting a check of type I/heterotic duality. We identify the holomorphic N = 1 variables for these compactifications. Matter fields and closed string moduli are both redefined by open string moduli. The redefinition of matter fields can be read directly from the perturbative Yukawa couplings, whereas closed string moduli redefinitions are obtained from D-brane instanton superpotential couplings. The resulting expressions reproduce and generalize, in the presence of internal magnetic fields, previous results in the literature.

  2. Hybrid Bloch brane

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Lima, Elisama E.M.; Losano, L. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil)

    2017-02-15

    This work reports on models described by two real scalar fields coupled with gravity in the five-dimensional spacetime, with a warped geometry involving one infinite extra dimension. Through a mechanism that smoothly changes a thick brane into a hybrid brane, one investigates the appearance of hybrid branes hosting internal structure, characterized by the splitting on the energy density and the volcano potential, induced by the parameter which controls interactions between the two scalar fields. In particular, we investigate distinct symmetric and asymmetric hybrid brane scenarios. (orig.)

  3. The landscape of theoretical physics a global view from point particles to the brane world and beyond, in search of a unifying principle

    CERN Document Server

    Pavšič, Matej

    2002-01-01

    This a book is for those who would like to learn something about special and general relativity beyond the usual textbooks, about quantum field theory, the elegant Fock-Schwinger-Stueckelberg proper time formalism, the elegant description of geometry by means of Clifford algebra, about the fascinating possibilities the latter algebra offers in reformulating the existing physical theories, and quantizing them in a natural way. It is shown how Clifford algebra provides much more: it provides room for new physics, with the prospects of resolving certain long standing puzzles. The theory of branes and the idea of how a 3-brane might represent our world is discussed in detail. Much attention is paid to the elegant geometric theory of branes which employs the infinite dimensional space of functions describing branes. Clifford algebra is generalized to the infinite dimensional spaces. In short, this is a book for anybody who would like to explore how the ``theory of everything'' might possibly be formulated. The the...

  4. Quark mass hierarchies in D-brane realizations of the Standard Model

    CERN Document Server

    Anastasopoulos, Pascal

    2010-01-01

    This proceeding is based on arXiv:0905.3044. We analyze the problem of the hierarchy of masses and mixings in orientifold realizations of the Standard Model. We present a bottom-up brane configuration that can generate such hierarchies.

  5. Quark mass hierarchies in D-brane realizations of the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Anastasopoulos, P. [I.N.F.N. - Sezione di Roma ' ' Tor Vergata' ' , 00133, Roma (Italy); Department of Physics, CERN - Theory Division, 1211 Geneva 23 (Switzerland). ROM2F/2009/26, CERN-PH-TH/2009-235; Lionetto, A. [I.N.F.N. - Sezione di Roma ' ' Tor Vergata' ' , 00133, Roma (Italy)

    2010-07-15

    This proceeding is based on the paper 0905.3044[hep-th]. We analyze the problem of the hierarchy of masses and mixings in orientifold realizations of the Standard Model. We present a bottom-up brane configuration that can generate such hierarchies. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  6. Extended Holography: Double-Trace Deformation and Brane-Induced Gravity Models

    Science.gov (United States)

    Barvinsky, A. O.

    2017-03-01

    We put forward a conjecture that for a special class of models - models of the double-trace deformation and brane-induced gravity types - the principle of holographic dualitiy can be extended beyond conformal invariance and anti-de Sitter (AdS) isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on the boundary.

  7. Inflationary solutions in the brane-world and their geometrical interpretation

    CERN Document Server

    Khoury, Justin; Waldram, Daniel; Khoury, Justin; Steinhardt, Paul J.; Waldram, Daniel

    2001-01-01

    We consider the cosmology of a pair of domain walls bounding a five-dimensional bulk space-time with negative cosmological constant, in which the distance between the branes is not fixed in time. Although there are strong arguments to suggest that this distance should be stabilized in the present epoch, no such constraints exist for the early universe and thus non-static solutions might provide relevant inflationary scenarios. We find the general solution for the standard ansatz where the bulk is foliated by planar-symmetric hypersurfaces. We show that in all cases the bulk geometry is that of anti-de Sitter (AdS_5). We then present a geometrical interpretation for the solutions as embeddings of two de Sitter (dS_4) surfaces in AdS_5, which provide a simple interpretation of the physical properties of the solutions. A notable feature explained in the analysis is that two-way communication between branes expanding away from one another is possible for a finite amount of time, after which communication can proc...

  8. On the localisation of four-dimensional brane-world black holes: II. The general case

    Science.gov (United States)

    Kanti, P.; Pappas, N.; Pappas, T.

    2016-01-01

    We perform a comprehensive analysis of a number of scalar field theories in an attempt to find analytically five-dimensional, localised-on-the-brane, black-hole solutions. Extending a previous analysis, we assume a generalised Vaidya ansatz for the five-dimensional metric tensor that allows for a time-dependent, non-trivial profile of the mass function in terms of the bulk coordinate and a deviation from the over-restricting Schwarzschild-type solution on the brane. In order to support such a solution, we study a variety of theories including single or multiple scalar fields, with canonical or non-canonical kinetic terms, minimally or non-minimally coupled to gravity. We demonstrate that for such a metric ansatz and for a carefully chosen energy-momentum tensor which is non-isotropic in five dimensions, solutions that have the form of a Schwarzschild-(anti)de Sitter or Reissner-Nordstrom type of solution do emerge. However, the resulting profile of the mass function along the bulk coordinate, when allowed, is not the correct one for eliminating bulk singularities.

  9. M5-brane and D-brane scattering amplitudes

    Science.gov (United States)

    Heydeman, Matthew; Schwarz, John H.; Wen, Congkao

    2017-12-01

    We present tree-level n-particle on-shell scattering amplitudes of various brane theories with 16 conserved supercharges. These include the world-volume theory of a probe D3-brane or D5-brane in 10D Minkowski spacetime as well as a probe M5-brane in 11D Minkowski spacetime, which describes self interactions of an abelian tensor supermultiplet with 6D (2, 0) supersymmetry. Twistor-string-like formulas are proposed for tree-level scattering amplitudes of all multiplicities for each of these theories. The R symmetry of the D3-brane theory is shown to be SU(4) × U(1), and the U(1) factor implies that its amplitudes are helicity conserving. Each of 6D theories (D5-brane and M5-brane) reduces to the D3-brane theory by dimensional reduction. As special cases of the general M5-brane amplitudes, we present compact formulas for examples involving only the self-dual B field with n = 4, 6, 8.

  10. Massive Branes

    NARCIS (Netherlands)

    Bergshoeff, E. A.; Lozano, Y.; Ortín, Tomas

    1997-01-01

    Published in: Nucl. Phys. B 518 (1998) 363-423 citations recorded in [Science Citation Index] Abstract: We investigate the effective worldvolume theories of branes in a background given by (the bosonic sector of) 10-dimensional massive IIA supergravity (``massive branes'') and their M-theoretic

  11. D-Branes in Curved Space

    Energy Technology Data Exchange (ETDEWEB)

    McGreevy, John Austen; /Stanford U., Phys. Dept.

    2005-07-06

    This thesis is a study of D-branes in string compactifications. In this context, D-branes are relevant as an important component of the nonperturbative spectrum, as an incisive probe of these backgrounds, and as a natural stringy tool for localizing gauge interactions. In the first part of the thesis, we discuss half-BPS D-branes in compactifications of type II string theory on Calabi-Yau threefolds. The results we describe for these objects are pertinent both in their role as stringy brane-worlds, and in their role as solitonic objects. In particular, we determine couplings of these branes to the moduli determining the closed-string geometry, both perturbatively and non-perturbatively in the worldsheet expansion. We provide a local model for transitions in moduli space where the BPS spectrum jumps, and discuss the extension of mirror symmetry between Calabi-Yau manifolds to the case when D-branes are present. The next section is an interlude which provides some applications of D-branes to other curved backgrounds of string theory. In particular, we discuss a surprising phenomenon in which fundamental strings moving through background Ramond-Ramond fields dissolve into large spherical D3-branes. This mechanism is used to explain a previously-mysterious fact discovered via the AdS-CFT correspondence. Next, we make a connection between type IIA string vacua of the type discussed in the first section and M-theory compactifications on manifolds of G{sub 2} holonomy. Finally we discuss constructions of string vacua which do not have large radius limits. In the final part of the thesis, we develop techniques for studying the worldsheets of open strings ending on the curved D-branes studied in the first section. More precisely, we formulate a large class of massive two-dimensional gauge theories coupled to boundary matter, which flow in the infrared to the relevant boundary conformal field theories. Along with many other applications, these techniques are used to describe

  12. Kalb-Ramond field localization on the Bloch brane

    Science.gov (United States)

    Cruz, W. T.; Maluf, R. V.; Almeida, C. A. S.

    2013-08-01

    This work deals with new results on the Kalb-Ramond (KR) field localization in brane-world models. We consider a five-dimensional warped spacetime with an embedded 4D thick brane which is generated by two real scalar fields coupled with gravity (the so called Bloch brane). We find a KR field zero mode localized with the inclusion of the dilaton coupling. Analyzing the massive spectrum, we detected a series of resonant modes that arise from the solutions of the Schrödinger-like equation for KR field. The effects of the brane thickness and of the dilaton coupling over the resonance structures are determined. Such analysis is extended to the resonance lifetimes of the massive modes, allowing a better understanding on the localization mechanism of the model.

  13. Backreacting D-brane instantons on branes at singularities

    Science.gov (United States)

    García-Valdecasas Tenreiro, Eduardo; Uranga, Angel

    2017-08-01

    Non-perturbative D-brane instanton effects in 4d N=1 string compactifications can be geometrized in terms of a backreacted generalized geometry. We extend earlier results to setups in which the D-brane instanton is charged under the 4d gauge symmetries, and show that the backreacted topology yields the correct charged field theory operators in the 4d effective action. In type IIA models with D6-branes, the backreaction of D2-brane instantons forces the recombination of D6-branes, such that the 4d charged field theory operators arise from basic worldsheet instantons in the backreacted geometry. We provide large classes of examples of D2-brane instanton effects on intersecting D6-brane systems in local models mirror to D3-branes at singularities. The backreacted geometry and the field theory operators are easily encoded in terms of simple operations in the graphs arising from the underlying dimer diagrams. This description agrees, in the appropriate cases, with the complex deformations triggered by certain fractional branes at the bottom of duality cascades.

  14. Starobinsky-Like Inflation in Dilaton-Brane Cosmology

    CERN Document Server

    Ellis, John; Nanopoulos, Dimitri V

    2014-01-01

    We discuss how Starobinsky-like inflation may emerge from dilaton dynamics in brane cosmology scenarios based on string theory, in which our universe is represented as a three-brane. The effective potential may acquire a constant term from a density of effectively point-like non-pertubative defects on the brane. Higher-genus corrections generate corrections to the effective potential that are exponentially damped at large field values, as in the Starobinsky model, but at a faster rate, leading to a smaller prediction for the tensor-to scalar perturbation ratio r. This may be compensated partially by logarithmic deformations on the world-sheet due to recoil of the defects due to scattering by string matter on the brane, which tend to enhance the tensor-to-scalar ratio.

  15. M2-brane dynamics in the classical limit of the BMN matrix model

    Directory of Open Access Journals (Sweden)

    Minos Axenides

    2017-10-01

    Full Text Available We investigate the large-N limit of the BMN matrix model by analyzing the dynamics of ellipsoidal M2-branes that spin in the 11-dimensional maximally supersymmetric SO(3×SO(6 plane-wave background. We identify finite-energy solutions by specifying the local minima of the corresponding energy functional. These configurations are static in SO(3 due to the Myers effect and rotate in SO(6 with an angular momentum that is bounded from above. As a first step towards studying their chaotic properties, we evaluate the Lyapunov exponents of their radial fluctuations.

  16. Introduction to strings and branes

    CERN Document Server

    West, Peter

    2012-01-01

    Supersymmetry, strings and branes are believed to be the essential ingredients in a single unified consistent theory of physics. This book gives a detailed, step-by-step introduction to the theoretical foundations required for research in strings and branes. After a study of the different formulations of the bosonic and supersymmetric point particles, the classical and quantum bosonic and supersymmetric string theories are presented. This book includes accounts of brane dynamics and D-branes and the T, S and U duality symmetries of string theory. The historical derivation of string theory is given as well as the sum over the world-sheet approach to the interacting string. More advanced topics include string field theory and Kac–Moody symmetries. The book contains pedagogical accounts of conformal quantum field theory, supergravity theories, Clifford algebras and spinors, and Lie algebras. It is essential reading for graduate students and researchers wanting to learn strings and branes.

  17. Spherically symmetric thick branes cosmological evolution

    Science.gov (United States)

    Bernardini, A. E.; Cavalcanti, R. T.; da Rocha, Roldão

    2015-01-01

    Spherically symmetric time-dependent solutions for the 5D system of a scalar field canonically coupled to gravity are obtained and identified as an extension of recent results obtained by Ahmed et al. (JHEP 1404:061. arXiv:1312.3576 [hep-th], 2014). The corresponding cosmology of models with regularized branes generated by such a 5D scalar field scenario is also investigated. It has been shown that the anisotropic evolution of the warp factor and consequently the Hubble like parameter are both driven by the radial coordinate on the brane, which leads to an emergent thick brane-world scenario with spherically symmetric time dependent warp factor. Meanwhile, the separability of variables depending on fifth dimension, , which is exhibited by the equations of motion, allows one to recover the extra dimensional profiles obtained in Ahmed et al. (2014), namely the extra dimensional part of the scale (warp) factor and the scalar field dependence on . Therefore, our results are mainly concerned with the time dependence of a spherically symmetric warp factor. Besides evincing possibilities for obtaining asymmetric stable brane-world scenarios, the extra dimensional profiles here obtained can also be reduced to those ones investigated in Ahmed et al. (2014).

  18. Kinks and branes in models with hyperbolic interactions

    Science.gov (United States)

    Bazeia, D.; Lima, Elisama E. M.; Losano, L.

    2017-09-01

    In this work, we investigate several models described by a single real scalar field with nonpolynomial interactions, constructed to support topological solutions. We do this using the deformation procedure to introduce a function which allows to construct two distinct families of hyperbolic potentials, controlled by three distinct parameters, in the standard formalism. In this way, the procedure allows us to get analytical solutions, and then investigate the energy density, linear stability and zero mode. We move on and introduce a nonstandard formalism to obtain compact solutions, analytically. We also investigate these hyperbolic models in the braneworld context, considering both the standard and nonstandard possibilities. The results show how to construct distinct braneworld models which are implemented via the first-order formalism and are stable against fluctuation of the metric tensor.

  19. Cosmology from quantum potential in a system of oscillating branes

    CERN Document Server

    Sepehri, Alireza

    2015-01-01

    Recently, some authors proposed a new mechanism which gets rid of the big-bang singularity and shows that the age of the universe is infinite. In this paper, we will confirm their results and predict that the universe may expand and contract many times in a system of oscillating branes. In this model, first, N fundamental strings transit to N M0-anti-M0-branes. Then, M0-branes join to each other and build an M8-anti-M8 system. This system is unstable, broken and two anti-M4-branes, a compactified M4-brane, an M3-brane in additional to one M0-brane are produced. The M3-brane wraps around the compactified M4-brane and both of them oscillate between two anti-M4-branes. Our universe is located on the M3-brane and interacts with other branes by exchanging the M0-brane and some scalars in transverse directions. By wrapping of M3-brane, universe contracts and generalized uncertainty principle or GUP emerges. By oscillating the compactified M4-M3-brane and approaching to one of anti-M4-branes, one end of M3-brane glu...

  20. D-Branes at Singularities A Bottom-Up Approach to the String Embedding of the Standard Model

    CERN Document Server

    Aldazabal, G.; Quevedo, F.; Uranga, A.M.

    2000-01-01

    We propose a bottom-up approach to the building of particle physics models from string theory. Our building blocks are Type II D-branes which we combine appropriately to reproduce desirable features of a particle theory model: 1) Chirality ; 2) Standard Model group ; 3) N=1 or N=0 supersymmetry ; 4) Three quark-lepton generations. We start such a program by studying configurations of D=10, Type IIB D3-branes located at singularities. We study in detail the case of Z_N, N=1,0 supersymmetric orbifold singularities leading to the SM group or some left-right symmetricextension. In general, tadpole cancellation conditions require the presence of additional branes, e.g. D7-branes. For the N=1 supersymmetric case the unique twist leading to three quark-lepton generations is Z_3, predicting $\\sin^2\\theta_W=3/14=0.21$. The models obtained are the simplest semirealistic string models ever built. In the non-supersymmetric case there is a three-generation model for each Z_N, N>4, but the Weinberg angle is in general too ...

  1. Effective superpotentials for B-branes in Landau-Ginzburg models

    CERN Document Server

    Govindarajan, S; Govindarajan, Suresh; Jockers, Hans

    2006-01-01

    We compute the partition function for the topological Landau-Ginzburg B-model on the disk. This is done by treating the worldsheet superpotential perturbatively. We argue that this partition function as a function of bulk and boundary perturbations may be identified with the effective D-brane superpotential in the target spacetime. We point out the relationship of this approach to matrix factorizations. Using these methods, we prove a conjecture for the effective superpotential of Herbst, Lazaroiu and Lerche for the A-type minimal models. We also consider the Landau-Ginzburg theory of the cubic torus where we show that the effective superpotential, given by the partition function, is consistent with the one obtained by summing up disk instantons in the mirror A-model. This is done by explicitly constructing the open-string mirror map.

  2. Massive branes and creation of branes

    NARCIS (Netherlands)

    Bergshoeff, E; Dorn, H; Lust, D; Weigt, G

    1998-01-01

    We investigate the effective worldvolume theories of p-branes and D-branes in a massive background given by (the bosonic sector of) 10-dimensional massive IIA supergravity ("massive branes"). As an application we discuss the consequences of our results for the anomalous creation of branes.

  3. Symmetry of Generalized Randall-Sundrum Model and Distribution of 3-Branes in Six-Dimensional Spacetime

    CERN Document Server

    Feng, Sheng-Fei; Huang, Yong-Chang; Liu, Xin; Zhao, Ying-Jie

    2015-01-01

    A generalization from the usual $5$-dimensional two-brane Randall-Sundrum (RS) model to a $6$-dimensional multi-brane RS model is presented. The extra dimensions are extended from one to two; correspondingly the single-variable warp function is generalized to be a double-variable function, to represent the two extra dimensions. In the analysis of the Einstein equation we have two remarkable discoveries. One is that, when branes are absent, the cosmological parameter distributed in the two extra dimensions acts as a function describing a family of circles. These circles are not artificially added ones but stem from the equations of motion, while their radii are inversely proportional to the square root of the cosmological parameter. The other discovery is that, on any circle, there symmetrically distribute four branes. Their tensions, $V_1 \\sim V_4$, satisfy a particular relationship $V_1=V_3=-V_2=-V_4=3M^4$, where $M$ is the $6$-dimensional fundamental scale of the RS model.

  4. On Branes and Oriented B fields

    Energy Technology Data Exchange (ETDEWEB)

    Shmakova, Marina

    2003-06-26

    Novel theories appear on the world-volume of branes by orienting B fields along various directions of the branes. We review some of the earlier developments and explore many new examples of these theories. In particular, among other things, we study the pinning effect of branes near conifold like singularities and brane-antibrane theories with different fluxes on their world-volumes. We show that all these theories arise from different limits of an M-theory configuration with appropriately chosen G-fluxes. This gives us a way to study them from a unified framework in M-theory.

  5. D-branes from Liouville strings

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, Dimitri V

    1997-01-01

    We develop quantization aspects of our Liouville approach to non-critical strings, proposing a path-integral formulation of a second quantization of string theory, that incorporates naturally the couplings of string sources to background fields. Such couplings are characteristic of macroscopic string solutions and/or D-brane theories. Resummation over world-sheet genera in the presence of stringy (\\sigma-model) soliton backgrounds, and recoil effects associated with logarithmic operators on the world sheet, play a crucial r\\^ole in inducing such sources as well-defined renormalization-group counterterms. Using our Liouville renormalization group approach, we derive the appropriate second-order equation of motion for the D brane. We discuss within this approach the appearance of open strings, whose ends carry non-trivial Chan-Paton-like quantum numbers related to the W_\\infty charges of two-dimensional string black holes.

  6. Lab-on-a-brane: A novel physiologically relevant planar arterial model to study transendothelial transport

    Science.gov (United States)

    Budhwani, Karim Ismail

    The tremendous quality of life impact notwithstanding, cardiovascular diseases and Cancer add up to over US$ 700bn each year in financial costs alone. Aging and population growth are expected to further expand the problem space while drug research and development remain expensive. However, preclinical costs can be substantially mitigated by substituting animal models with in vitro devices that accurately model human cardiovascular transport. Here we present a novel physiologically relevant lab-on-a-brane that simulates in vivo pressure, flow, strain, and shear waveforms associated with normal and pathological conditions in large and small blood vessels for studying molecular transport across the endothelial monolayer. The device builds upon previously demonstrated integrated microfluidic loop design by: (a) introducing nanoscale pores in the substrate membrane to enable transmembrane molecular transport, (b) transforming the substrate membrane into a nanofibrous matrix for 3D smooth muscle cell (SMC) tissue culture, (c) integrating electrospinning fabrication methods, (d) engineering an invertible sandwich cell culture device architecture, and (e) devising a healthy co-culture mechanism for human arterial endothelial cell (HAEC) monolayer and multiple layers of human smooth muscle cells (HSMC) to accurately mimic arterial anatomy. Structural and mechanical characterization was conducted using confocal microscopy, SEM, stress/strain analysis, and infrared spectroscopy. Transport was characterized using FITC-Dextran hydraulic permeability protocol. Structure and transport characterization successfully demonstrate device viability as a physiologically relevant arterial mimic for testing transendothelial transport. Thus, our lab-on-a-brane provides a highly effective and efficient, yet considerably inexpensive, physiologically relevant alternative for pharmacokinetic evaluation; possibly reducing animals used in pre-clinical testing, clinical trials cost from false

  7. Brane Effective Actions, Kappa-Symmetry and Applications

    Directory of Open Access Journals (Sweden)

    Joan Simón

    2012-02-01

    Full Text Available This is a review on brane effective actions, their symmetries and some of their applications. Its first part covers the Green–Schwarz formulation of single M- and D-brane effective actions focusing on kinematical aspects: the identification of their degrees of freedom, the importance of world volume diffeomorphisms and kappa symmetry to achieve manifest spacetime covariance and supersymmetry, and the explicit construction of such actions in arbitrary on-shell supergravity backgrounds. Its second part deals with applications. First, the use of kappa symmetry to determine supersymmetric world volume solitons. This includes their explicit construction in flat and curved backgrounds, their interpretation as Bogomol’nyi–Prasad–Sommerfield (BPS states carrying (topological charges in the supersymmetry algebra and the connection between supersymmetry and Hamiltonian BPS bounds. When available, I emphasise the use of these solitons as constituents in microscopic models of black holes. Second, the use of probe approximations to infer about the non-trivial dynamics of strongly-coupled gauge theories using the anti de Sitter/conformal field theory (AdS/CFT correspondence. This includes expectation values of Wilson loop operators, spectrum information and the general use of D-brane probes to approximate the dynamics of systems with small number of degrees of freedom interacting with larger systems allowing a dual gravitational description. Its final part briefly discusses effective actions for N D-branes and M2-branes. This includes both Super-Yang-Mills theories, their higher-order corrections and partial results in covariantising these couplings to curved backgrounds, and the more recent supersymmetric Chern–Simons matter theories describing M2-branes using field theory, brane constructions and 3-algebra considerations.

  8. Highly symmetric D-brane-anti-D-brane effective actions

    Science.gov (United States)

    Hatefi, Ehsan

    2017-09-01

    The entire S-matrix elements of four, five and six point functions of D-brane-anti D-brane system are explored. To deal with symmetries of string amplitudes as well as their all order α ' corrections we first address a four point function of one closed string Ramond-Ramond (RR) and two real tachyons on the world volume of brane-anti brane system. We then focus on symmetries of string theory as well as universal tachyon expansion to achieve both string and effective field theory of an RR and three tachyons where the complete algebraic analysis for the whole S-matrix was also revealed. Lastly, we employ all the conformal field theory techniques to , working out with symmetries of theory and find out the expansion for the amplitude to be able to precisely discover all order singularity structures of D-brane-anti-D-brane effective actions of string theory. Various remarks about the so called generalized Veneziano amplitude and new string couplings are elaborated as well.

  9. Dark Radiation and Localization of Gravity on the Brane

    OpenAIRE

    Neves, Rui; Vaz, Cenalo

    2002-01-01

    We discuss the dynamics of a spherically symmetric dark radiation vaccum in the Randall-Sundrum brane world scenario. Under certain natural assumptions we show that the Einstein equations on the brane form a closed system. For a de Sitter brane we determine exact dynamical and inhomogeneous solutions which depend on the brane cosmological constant, on the dark radiation tidal charge and on its initial configuration. We define the conditions leading to singular or globally re...

  10. Brane cosmology in teleparallel and f (T ) gravity

    Science.gov (United States)

    Atazadeh, K.; Eghbali, A.

    2015-04-01

    We consider the cosmology of a brane-world scenario in the framework of teleparallel and f(T) gravity in a way that matter is localized on the brane. We show that the cosmology of such branes is different from the standard cosmology in teleparallelism. In particular, we obtain a class of new solutions with a constant five-dimensional radius and cosmologically evolving brane in the context of constant torsion f(T) gravity.

  11. Minimal D=7 supergravity and the supersymmetry of Arnold-Beltrami flux branes

    Energy Technology Data Exchange (ETDEWEB)

    Fré, P. [Dipartimento di Fisica, Università di Torino,via P. Giuria 1, 10125 Torino (Italy); INFN - Sezione di Torino,via P. Giuria 1, 10125 Torino (Italy); MEPhI (Moscow Engineering Physics Institute), National Research Nuclear University,Kashirskoye shosse 31, 115409 Moscow (Russian Federation); Grassi, P.A. [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale,Viale T. Michel 11, 15121 Alessandria (Italy); INFN - Sezione di Torino,via P. Giuria 1, 10125 Torino (Italy); Ravera, L.; Trigiante, M. [DISAT, Politecnico di Torino,C.so Duca degli Abruzzi, 24, I-10129 Torino (Italy); INFN - Sezione di Torino,via P. Giuria 1, 10125 Torino (Italy)

    2016-06-06

    In this paper we study some properties of the newly found Arnold-Beltrami flux-brane solutions to the minimal D=7 supergravity. To this end we first single out the appropriate Free Differential Algebra containing both a gauge 3-form B{sup [3]} and a gauge 2-form B{sup [2]}: then we present the complete rheonomic parametrization of all the generalized curvatures. This allows us to identify two-brane configurations with Arnold-Beltrami fluxes in the transverse space with exact solutions of supergravity and to analyze the Killing spinor equation in their background. We find that there is no preserved supersymmetry if there are no additional translational Killing vectors. Guided by this principle we explicitly construct Arnold-Beltrami flux two-branes that preserve 0, (1/8) and (1/4) of the original supersymmetry. Two-branes without fluxes are instead BPS states and preserve (1/2) supersymmetry. For each two-brane solution we carefully study its discrete symmetry that is always given by some appropriate crystallographic group Γ. Such symmetry groups Γ are transmitted to the D=3 gauge theories on the brane world-volume that would occur in the gauge/gravity correspondence. Furthermore we illustrate the intriguing relation between gauge fluxes in two-brane solutions and hyperinstantons in D=4 topological sigma-models.

  12. Minimal D = 7 supergravity and the supersymmetry of Arnold-Beltrami flux branes

    Science.gov (United States)

    Fré, P.; Grassi, P. A.; Ravera, L.; Trigiante, M.

    2016-06-01

    In this paper we study some properties of the newly found Arnold-Beltrami flux-brane solutions to the minimal D = 7 supergravity. To this end we first single out the appropriate Free Differential Algebra containing both a gauge 3-form B [3] and a gauge 2-form B [2]: then we present the complete rheonomic parametrization of all the generalized curvatures. This allows us to identify two-brane configurations with Arnold-Beltrami fluxes in the transverse space with exact solutions of supergravity and to analyze the Killing spinor equation in their background. We find that there is no preserved supersymmetry if there are no additional translational Killing vectors. Guided by this principle we explicitly construct Arnold-Beltrami flux two-branes that preserve 0, 1/8 and 1/4 of the original supersymmetry. Two-branes without fluxes are instead BPS states and preserve 1/2 supersymmetry. For each two-brane solution we carefully study its discrete symmetry that is always given by some appropriate crystallographic group Γ. Such symmetry groups Γ are transmitted to the D = 3 gauge theories on the brane world-volume that would occur in the gauge/gravity correspondence. Furthermore we illustrate the intriguing relation between gauge fluxes in two-brane solutions and hyperinstantons in D = 4 topological sigma-models.

  13. LHC Phenomenology and Cosmology of String-Inspired Intersecting D-Brane Models

    CERN Document Server

    Anchordoqui, Luis A.; Goldberg, Haim; Huang, Xing; Lust, Dieter; Taylor, Tomasz R.; Vlcek, Brian

    2012-01-01

    We discuss the phenomenology and cosmology of a Standard-like Model inspired by string theory, in which the gauge fields are localized on D-branes wrapping certain compact cycles on an underlying geometry, whose intersection can give rise to chiral fermions. The energy scale associated with string physics is assumed to be near the Planck mass. To develop our program in the simplest way, we work within the construct of a minimal model with gauge-extended sector U (3)_B \\times Sp (1)_L \\times U (1)_{I_R} \\times U (1)_L. The resulting U (1) content gauges the baryon number B, the lepton number L, and a third additional abelian charge I_R which acts as the third isospin component of an SU(2)_R. All mixing angles and gauge couplings are fixed by rotation of the U(1) gauge fields to a basis diagonal in hypercharge Y and in an anomaly free linear combination of I_R and B-L. The anomalous $Z'$ gauge boson obtains a string scale St\\"uckelberg mass via a 4D version of the Green-Schwarz mechanism. To keep the realizatio...

  14. Nucleation of {sup (4)}R brane universes

    Energy Technology Data Exchange (ETDEWEB)

    Cordero, Ruben [Departamento de FIsica, Escuela Superior de FIsica y Matematicas del IPN, Unidad Adolfo Lopez Mateos, Edificio 9, 07738 Mexico, DF (Mexico); Rojas, EfraIn [Facultad de FIsica e Inteligencia Artificial, Universidad Veracruzana, Sebastian Camacho 5, Xalapa, Veracruz, 91000 (Mexico)

    2004-09-07

    The creation of brane universes induced by a totally antisymmetric tensor living in a fixed background spacetime is presented, where a term involving the intrinsic curvature of the brane is considered. A canonical quantum mechanical approach employing the Wheeler-DeWitt equation is used. The probability nucleation for the brane is calculated by means of the corresponding instanton and the WKB approximation. Some cosmological implications from the model are presented.

  15. Calculable Corrections to Brane Black Hole Decay II Greybody Factors for Spin 1\\/2 and 1

    CERN Document Server

    Kanti, Panagiota; Kanti, Panagiota; March-Russell, John

    2003-01-01

    The production of black holes in extra-dimensional brane-world theories can lead to detectable signals via the Hawking evaporation of the black hole to brane-localized Standard Model modes. We calculate, as a function of partial wave number and number of toroidally compactified extra dimensions, the leading correction to the energy spectrum of such Hawking radiation (the greybody factors) for decay into spin 1/2 fermions and spin 1 gauge fields localised on the Standard Model brane. The greybody factors for both types of fields are enhanced as the number of extra dimensions increases.

  16. Bianchi type I universe in brane world scenario with non-zero Weyl tensor of the bulk

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, S. [University of Burdwan, Department of Physics, Burdwan (India)

    2017-09-15

    In the paper, we present exact solutions of gravitational field equations for an anisotropic brane with a Bianchi type I universe with perfect fluid having non-vanishing Weyl tensor of the bulk. It is assumed that the thermodynamic pressure bears a linear relation with the energy density. For a particular non-zero value of the pressure the solutions are obtained in an exact analytic form with and without the cosmological constant for a Bianchi type I universe. The relevant physical quantities associated with the evolution of the universe are also derived in the two cases. (orig.)

  17. Bianchi type I universe in brane world scenario with non-zero Weyl tensor of the bulk

    Science.gov (United States)

    Chaudhuri, S.

    2017-09-01

    In the paper, we present exact solutions of gravitational field equations for an anisotropic brane with a Bianchi type I universe with perfect fluid having non-vanishing Weyl tensor of the bulk. It is assumed that the thermodynamic pressure bears a linear relation with the energy density. For a particular non-zero value of the pressure the solutions are obtained in an exact analytic form with and without the cosmological constant for a Bianchi type I universe. The relevant physical quantities associated with the evolution of the universe are also derived in the two cases.

  18. E3-brane instantons and baryonic operators for D3-branes on toric singularities

    CERN Document Server

    Forcella, Davide; Uranga, Angel M

    2009-01-01

    We consider the couplings induced on the world-volume field theory of D3-branes at local toric Calabi-Yau singularities by euclidean D3-brane (E3-brane) instantons wrapped on (non-compact) holomorphic 4-cycles. These instantons produce insertions of BPS baryonic or mesonic operators of the four-dimensional ${\\cal{N}}=1$ quiver gauge theory. We argue that these systems underlie, via the near-horizon limit, the familiar AdS/CFT map between BPS operators and D3-branes wrapped on supersymmetric 3-cycles on the 5d horizon. The relation implies that there must exist E3-brane instantons with appropriate fermion mode spectrum and couplings, such that their non-perturbative effects on the D3-branes induce operators forming a generating set for all BPS operators of the quiver CFT. We provide a constructive argument for this correspondence, thus supporting the picture.

  19. Orientifold dual for stuck NS5 branes

    CERN Document Server

    Feng, B; Karch, A; Uranga, Angel M; Feng, Bo; He, Yang-Hui; Karch, Andreas; Uranga, Angel

    2001-01-01

    We establish T-duality between NS5 branes stuck on an orientifold 8-plane in type I' and an orientifold construction in type IIB with D7 branes intersecting at angles. Two applications are discussed. For one we obtain new brane constructions, realizing field theories with gauge group a product of symplectic factors, giving rise to a large new class of conformal N=1 theories embedded in string theory. Second, by studying a D2 brane probe in the type I' background, we get some information on the still elusive (0,4) linear sigma model describing a perturbative heterotic string on an ADE singularity.

  20. D-Branes on K3-Fibrations

    CERN Document Server

    Kaste, P.; Lutken, C.A.; Walcher, Johannes

    2000-01-01

    B-type D-branes are constructed on two different K3-fibrations over IP_1 using boundary conformal field theory at the rational Gepner points of these models. The microscopic CFT charges are compared with the Ramond charges of D-branes wrapped on holomorphic cycles of the corresponding Calabi-Yau manifold. We study in particular D4-branes and bundles localized on the K3 fibers, and find agreement with expectations. This provides a further test of the boundary CFT approach to $D$-brane physics.

  1. Class of probe brane universes

    Science.gov (United States)

    Vasilić, Milovan

    2013-06-01

    I examine the idea that our world is a branelike object of negligible influence on the bulk spacetime. No particular action functional is specified. Instead, the probe brane dynamics is derived from the universally valid stress-energy conservation equations. As an example, I study the case of a three-sphere in the five-dimensional Minkowski spacetime. The resulting four-universe turns out to depend on the equation of state of the brane constituent matter but differs from that of general relativity. One observes that, for every general relativistic universe, there exists a brane universe of equal geometry but a slightly different equation of state. As for the stability of brane universes, I find that no equation of state leads to a stable solution. However, the situation changes if the bulk spacetime has a Euclidean signature. In this case, a class of stable cosmological solutions is obtained. The brane vibrations are guided by the covariant Klein-Gordon equation with an effective metric of the Minkowski signature. It is this effective metric that local observers actually detect. As a consequence, the detected Universe is of bouncing type, with an accelerating expanding phase.

  2. Brane singularities and their avoidance

    CERN Document Server

    Antoniadis, I; klaoudatou, I

    2010-01-01

    The singularity structure and the corresponding asymptotic behavior of a 3-brane coupled to a scalar field or to a perfect fluid in a five-dimensional bulk is analyzed in full generality using the method of asymptotic splittings. In the case of the scalar field, it is shown that the collapse singularity at a finite distance from the brane can be avoided only at the expense of making the brane world-volume positively or negatively curved. In the case where the bulk field content is parametrized by an analogue of perfect fluid with an arbitrary equation of state P=\\gamma\\rho between the `pressure' P and the `density' \\rho, our results depend crucially on the constant fluid parameter \\gamma: (i) For \\gamma>-1/2, the flat brane solution suffers from a collapse singularity at finite distance, that disappears in the curved case. (ii) For \\gamma<-1, the singularity cannot be avoided and it becomes of the big rip type for a flat brane. (iii) For -1<\\gamma< or = -1/2, the surprising result is found that while...

  3. Super D-branes revisited

    NARCIS (Netherlands)

    Bergshoeff, E.; Townsend, P.K.

    1998-01-01

    A version of the κ-symmetric super Dp-brane action is presented in which the tension is a dynamical variable, equal to the flux of a p-form world-volume gauge field. The Lagrangian is shown to be invariant under all (super)isometries of the background for appropriate transformations of the

  4. Classical tests of General Relativity in thick branes

    Science.gov (United States)

    Dahia, F.; de Albuquerque Silva, Alex

    2015-02-01

    Classical tests of General Relativity in braneworld scenarios have been investigated recently with the purpose of posing observational constraints on the parameters of some models of infinitely thin brane. Here we consider the motion of test particles in a thick brane scenario that corresponds to a regularized version of the Garriga-Tanaka solution, which describes a black hole solution in RSII model, in the weak field regime. By adapting a mechanism previously formulated in order to describe the confinement of massive tests particles in a domain wall (which simulates classically the trapping of the Dirac field in a domain wall), we study the influence of the brane thickness on the four-dimensional (4D) path of massless particles. Although the geometry is not warped and, therefore, the bound motion in the transverse direction is not decoupled from the movement in the 4D-world, we can find an explicit solution for the light deflection and the time delay, if the motion in the fifth direction is a high frequency oscillation. We verify that, owing to the transverse motion, the light deflection and the time delay depend on the energy of the light rays. This feature may lead to the phenomenon of gravitational rainbow. We also consider the problem from a semi-classical perspective, investigating the effects of the brane thickness on the motion of the zero-mode in the 4D-world.

  5. World Magnetic Model 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  6. World Magnetic Model 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  7. Self-accelerated brane Universe with warped extra dimension

    CERN Document Server

    Gorbunov, D S

    2008-01-01

    We propose a cosmological model which exhibits the phenomenon of self-acceleration: the Universe is attracted to the phase of accelerated expansion at late times even in the absence of the cosmological constant. The self-acceleration is inevitable in the sense that it cannot be neutralized by any negative explicit cosmological constant. The model is formulated in the framework of brane-world theories with a warped extra dimension. The key ingredient of the model is the brane-bulk energy transfer which is carried by bulk vector fields with a sigma-model-like boundary condition on the brane. We explicitly find the 5-dimensional metric corresponding to the late-time de Sitter expansion on the brane; this metric describes an AdS_5 black hole with growing mass. The present value of the Hubble parameter implies the scale of new physics of order 1 TeV, where the proposed model has to be replaced by putative UV-completion. The mechanism leading to the self-acceleration has AdS/CFT interpretation as occurring due to s...

  8. Poisson Lie symmetry and D-branes in WZW model on the Heisenberg Lie group H4

    Directory of Open Access Journals (Sweden)

    A. Eghbali

    2015-10-01

    Full Text Available We show that the WZW model on the Heisenberg Lie group H4 has Poisson–Lie symmetry only when the dual Lie group is A2⊕2A1. In this way, we construct the mutual T-dual sigma models on Drinfel'd double generated by the Heisenberg Lie group H4 and its dual pair, A2⊕2A1, as the target space in such a way that the original model is the same as the H4 WZW model. Furthermore, we show that the dual model is conformal up to two-loop order. Finally, we discuss D-branes and the worldsheet boundary conditions defined by a gluing matrix on the H4 WZW model. Using the duality map obtained from the canonical transformation description of the Poisson–Lie T-duality transformations for the gluing matrix which locally defines the properties of the D-brane, we find two different cases of the gluing matrices for the WZW model based on the Heisenberg Lie group H4 and its dual model.

  9. BlackMax: A black-hole event generator with rotation, recoil, split branes and brane tension

    OpenAIRE

    Dai, De-Chang; Starkman, Glenn; Stojkovic, Dejan; Issever, Cigdem; Rizvi, Eram; Tseng, Jeff

    2007-01-01

    We present a comprehensive black-hole event generator, BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole graybody f...

  10. Microstates of black holes in expanding universe from interacting branes

    Science.gov (United States)

    Shiba, Shotaro

    2017-05-01

    Thermodynamics of the near extremal black p-branes can be described by collective motions of gravitationally interacting branes. This proposal is called the p-soup model. In this paper, we check this proposal in the case of black brane system which is asymptotically Friedmann-Lemaître-Robertson-Walker universe in an infinite distance. As a result, we can show that the gravitationally interacting branes explain free energy, entropy, temperature and other physical quantities in these systems. This implies that the microstates of this kind of brane system can be also understood in the p-soup model.

  11. Compact T-branes

    Science.gov (United States)

    Marchesano, Fernando; Savelli, Raffaele; Schwieger, Sebastian

    2017-09-01

    We analyse global aspects of 7-brane backgrounds with a non-commuting profile for their worldvolume scalars, also known as T-branes. In particular, we consider configurations with no poles and globally well-defined over a compact Kähler surface. We find that such T-branes cannot be constructed on surfaces of positive or vanishing Ricci curvature. For the existing T-branes, we discuss their stability as we move in Kähler moduli space at large volume and provide examples of T-branes splitting into non-mutually-supersymmetric constituents as they cross a stability wall.

  12. Full linear perturbations and localization of gravity on f(R, T) brane

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Bao-Min; Zhang, Yu-Peng; Yu, Hao; Liu, Yu-Xiao [Lanzhou University, Institute of Theoretical Physics, Lanzhou (China)

    2017-02-15

    We study the thick brane world system constructed in the recently proposed f(R, T) theories of gravity, with R the Ricci scalar and T the trace of the energy-momentum tensor. We try to get the analytic background solutions and discuss the full linear perturbations, especially the scalar perturbations. We compare how the brane world model is modified with that of general relativity coupled to a canonical scalar field. It is found that some more interesting background solutions are allowed, and only the scalar perturbation mode is modified. There is no tachyon state existing in this model and only the massless tensor mode can be localized on the brane, which recovers the effective four-dimensional gravity. These conclusions hold provided that two constraints on the original formalism of the action are satisfied. (orig.)

  13. Full linear perturbations and localization of gravity on f( R, T) brane

    Science.gov (United States)

    Gu, Bao-Min; Zhang, Yu-Peng; Yu, Hao; Liu, Yu-Xiao

    2017-02-01

    We study the thick brane world system constructed in the recently proposed f( R, T) theories of gravity, with R the Ricci scalar and T the trace of the energy-momentum tensor. We try to get the analytic background solutions and discuss the full linear perturbations, especially the scalar perturbations. We compare how the brane world model is modified with that of general relativity coupled to a canonical scalar field. It is found that some more interesting background solutions are allowed, and only the scalar perturbation mode is modified. There is no tachyon state existing in this model and only the massless tensor mode can be localized on the brane, which recovers the effective four-dimensional gravity. These conclusions hold provided that two constraints on the original formalism of the action are satisfied.

  14. New exact cosmologies on the brane

    Science.gov (United States)

    Astashenok, Artyom V.; Yurov, Artyom V.; Chervon, Sergey V.; Shabanov, Evgeniy V.; Sami, Mohammad

    2014-10-01

    We develop a method for constructing exact cosmological solutions in brane world cosmology. New classes of cosmological solutions on Randall-Sandrum brane are obtained. The superpotential and Hubble parameter are represented in quadratures. These solutions have inflationary phases under general assumptions and also describe an exit from the inflationary phase without a fine tuning of the parameters. Another class solutions can describe the current phase of accelerated expansion with or without possible exit from it.

  15. A Note on Asymmetric Thick Branes

    Directory of Open Access Journals (Sweden)

    D. Bazeia

    2014-01-01

    Full Text Available We study asymmetric thick braneworld scenarios, generated after adding a constant to the superpotential associated with the scalar field. We study in particular models with odd and even polynomial superpotentials, and we show that asymmetric brane can be generated irrespective of the potential being symmetric or asymmetric. We study in addition the nonpolynomial sine-Gordon like model, also constructed with the inclusion of a constant in the standard superpotential, and we investigate gravitational stability of the asymmetric brane. The results suggest robustness of the new braneworld scenarios and add further possibilities of the construction of asymmetric branes.

  16. Accidental SUSY: enhanced bulk supersymmetry from brane back-reaction

    Science.gov (United States)

    Burgess, C. P.; van Nierop, L.; Parameswaran, S.; Salvio, A.; Williams, M.

    2013-02-01

    We compute how bulk loops renormalize both bulk and brane effective interactions for codimension-two branes in 6D gauged chiral supergravity, as functions of the brane tension and brane-localized flux. We do so by explicitly integrating out hyper- and gauge-multiplets in 6D gauged chiral supergravity compactified to 4D on a flux-stabilized 2D rugby-ball geometry, specializing the results of a companion paper, arXiv:1210.3753, to the supersymmetric case. While the brane back-reaction generically breaks supersymmetry, we show that the bulk supersymmetry can be preserved if the amount of brane- localized flux is related in a specific BPS-like way to the brane tension, and verify that the loop corrections to the brane curvature vanish in this special case. In these systems it is the brane-bulk couplings that fix the size of the extra dimensions, and we show that in some circumstances the bulk geometry dynamically adjusts to ensure the supersymmetric BPS-like condition is automatically satisfied. We investigate the robustness of this residual supersymmetry to loops of non-supersymmetric matter on the branes, and show that supersymmetry-breaking effects can enter only through effective brane-bulk interactions involving at least two derivatives. We comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.

  17. Pure geometric thick f( R)-branes: stability and localization of gravity

    Science.gov (United States)

    Zhong, Yuan; Liu, Yu-Xiao

    2016-06-01

    We study two exactly solvable five-dimensional thick brane world models in pure metric f( R) gravity. Working in the Einstein frame, we show that these solutions are stable against small linear perturbations, including the tensor, vector, and scalar modes. For both models, the corresponding gravitational zero mode is localized on the brane, which leads to the four-dimensional Newton law; while the massive modes are non-localized and only contribute a small correction to the Newton law at a large distance.

  18. Pure geometric thick f(R)-branes: stability and localization of gravity

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuan; Liu, Yu-Xiao [Lanzhou University, Institute of Theoretical Physics, Lanzhou (China)

    2016-06-15

    We study two exactly solvable five-dimensional thick brane world models in pure metric f(R) gravity. Working in the Einstein frame, we show that these solutions are stable against small linear perturbations, including the tensor, vector, and scalar modes. For both models, the corresponding gravitational zero mode is localized on the brane, which leads to the four-dimensional Newton law; while the massive modes are non-localized and only contribute a small correction to the Newton law at a large distance. (orig.)

  19. Non-geometric five-branes in heterotic supergravity

    Science.gov (United States)

    Sasaki, Shin; Yata, Masaya

    2016-11-01

    We study T-duality chains of five-branes in heterotic supergravity where the first order α'-corrections are present. By performing the α'-corrected T-duality transformations of the heterotic NS5-brane solutions, we obtain the KK5-brane and the exotic 5 2 2 -brane solutions associated with the symmetric, the neutral and the gauge NS5-branes. We find that the Yang-Mills gauge field in these solutions satisfies the self-duality condition in the three- and two-dimensional transverse spaces to the brane world-volumes. The O(2 , 2) monodromy structures of the 5 2 2 -brane solutions are investigated by the α'-corrected generalized metric. Our analysis shows that the symmetric 5 2 2 -brane solution, which satisfies the standard embedding condition, is a T-fold and it exhibits the non-geometric nature. We also find that the neutral 5 2 2 -brane solution is a T-fold at least at O({α}^') . On the other hand, the gauge 5 2 2 -brane solution is not a T-fold but show unusual structures of space-time.

  20. Non-geometric five-branes in heterotic supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Shin; Yata, Masaya [Department of Physics, Kitasato University,Sagamihara 252-0373 (Japan); Department of Physics, National University of Singapore,2, Science Drive 3, Singapore 117542 (Singapore)

    2016-11-10

    We study T-duality chains of five-branes in heterotic supergravity where the first order α{sup ′}-corrections are present. By performing the α{sup ′}-corrected T-duality transformations of the heterotic NS5-brane solutions, we obtain the KK5-brane and the exotic 5{sub 2}{sup 2}-brane solutions associated with the symmetric, the neutral and the gauge NS5-branes. We find that the Yang-Mills gauge field in these solutions satisfies the self-duality condition in the three- and two-dimensional transverse spaces to the brane world-volumes. The O(2,2) monodromy structures of the 5{sub 2}{sup 2}-brane solutions are investigated by the α{sup ′}-corrected generalized metric. Our analysis shows that the symmetric 5{sub 2}{sup 2}-brane solution, which satisfies the standard embedding condition, is a T-fold and it exhibits the non-geometric nature. We also find that the neutral 5{sub 2}{sup 2}-brane solution is a T-fold at least at O(α{sup ′}). On the other hand, the gauge 5{sub 2}{sup 2}-brane solution is not a T-fold but show unusual structures of space-time.

  1. M-theory, graphene-branes and superconducting wormholes

    Science.gov (United States)

    Sepehri, Alireza; Pincak, Richard; Olmo, Gonzalo J.

    Exploiting an M-brane system whose structure and symmetries are inspired by those of graphene (what we call a graphene-brane), we propose here a similitude between two layers of graphene joined by a nanotube and wormholes scenarios in the brane world. By using the symmetries and mathematical properties of the M-brane system, we show here how to possibly increase its conductivity, to the point of making it as a superconductor. The questions of whether and under which condition this might point to the corresponding real graphene structures becoming superconducting are briefly outlined.

  2. Note on M2-branes in opposite charge

    Science.gov (United States)

    Blâbäck, Johan

    2014-03-01

    The flux singularity that arises for branes in oppositely charged fluxes is a widely discussed issue and in this paper the problem is investigated further. New AdS world volume (anti-)M2-brane solutions are constructed using space-filling branes placed in fluxes of opposite dissolved charge that is opposite to that of the brane. A topological obstruction is derived to show how the singularity develops during localization of this solution and any similarly constructed solution. Furthermore it is shown that it is not possible to hide the singularity behind a horizon, which would have given credence to an M theory resolution.

  3. BlackMax: A black-hole event generator with rotation, recoil, split branes, and brane tension

    Science.gov (United States)

    Dai, De-Chang; Starkman, Glenn; Stojkovic, Dejan; Issever, Cigdem; Rizvi, Eram; Tseng, Jeff

    2008-04-01

    We present a comprehensive black-hole event generator, BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole gray-body factors known to date and incorporates the effects of black-hole rotation, splitting between the fermions, nonzero brane tension, and black-hole recoil due to Hawking radiation (although not all simultaneously). The generator can be interfaced with Herwig and Pythia. The main code can be downloaded from http://www-pnp.physics.ox.ac.uk/~issever/BlackMax/blackmax.html.

  4. Branes constrictions with White Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    García-Aspeitia, Miguel A., E-mail: aspeitia@fisica.uaz.edu.mx [Consejo Nacional de Ciencia y Tecnología, Av, Insurgentes Sur 1582, Colonia Crédito Constructor, Del. Benito Juárez, C.P. 03940, Mexico, D.F. (Mexico); Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esquina con Paseo a la Bufa S/N, C.P. 98060, Zacatecas (Mexico)

    2015-11-06

    We consider here a robust study of stellar dynamics for white dwarf stars with polytropic matter in the weak-field approximation using the Lane–Emden equation from the brane-world scenario. We also derive an analytical solution to the nonlocal energy density and show the behavior and sensitivity of these stars to the presence of extra dimensions. Similarly, we analyze stability and compactness, in order to show whether it is possible to agree with the conventional wisdom of white dwarfs dynamics. Our results predict an average value of the brane tension of <λ>≳84.818 MeV{sup 4}, with a standard deviation σ≃82.021 MeV{sup 4}, which comes from a sample of dwarf stars, being weaker than other astrophysical observations but remaining higher than cosmological results provided by nucleosynthesis among others.

  5. Branes constrictions with White Dwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Aspeitia, Miguel A. [Consejo Nacional de Ciencia y Tecnologia, Mexico (Mexico); Unidad Academica de Fisica, Universidad Autonoma de Zacatecas (Mexico)

    2015-11-15

    We consider here a robust study of stellar dynamics for white dwarf stars with polytropic matter in the weak-field approximation using the Lane-Emden equation from the brane-world scenario. We also derive an analytical solution to the nonlocal energy density and show the behavior and sensitivity of these stars to the presence of extra dimensions. Similarly, we analyze stability and compactness, in order to show whether it is possible to agree with the conventional wisdom of white dwarfs dynamics. Our results predict an average value of the brane tension of left angle λ right angle >or similar 84.818 MeV{sup 4}, with a standard deviation σ ≅ 82.021 MeV{sup 4}, which comes from a sample of dwarf stars, being weaker than other astrophysical observations but remaining higher than cosmological results provided by nucleosynthesis among others. (orig.)

  6. Branes constrictions with White Dwarfs

    Science.gov (United States)

    García-Aspeitia, Miguel A.

    2015-11-01

    We consider here a robust study of stellar dynamics for white dwarf stars with polytropic matter in the weak-field approximation using the Lane-Emden equation from the brane-world scenario. We also derive an analytical solution to the nonlocal energy density and show the behavior and sensitivity of these stars to the presence of extra dimensions. Similarly, we analyze stability and compactness, in order to show whether it is possible to agree with the conventional wisdom of white dwarfs dynamics. Our results predict an average value of the brane tension of < λ rangle ≳ 84.818MeV^4, with a standard deviation σ ˜eq 82.021MeV^4, which comes from a sample of dwarf stars, being weaker than other astrophysical observations but remaining higher than cosmological results provided by nucleosynthesis among others.

  7. Multiple intersections of D-branes and M-branes

    NARCIS (Netherlands)

    Bergshoeff, E.; Roo, M. de; Eyras, E.; Janssen, B.; Schaar, J.P. van der

    1997-01-01

    We give a classification of all multiple intersections of D-branes in ten dimensions and M-branes in eleven dimensions that correspond to threshold BPS bound states. The residual supersymmetry of these composite branes is determined. By dimensional reduction composite p-branes in lower dimensions

  8. Exotic branes and non-perturbative seven branes

    NARCIS (Netherlands)

    Eyras, E; Lozano, Y

    2000-01-01

    We construct the effective action of certain exotic branes in the Type Ii theories which are not predicted by their space-time supersymmetry algebras. We analyze in detail the case of the NS-7B brane, S-dual to the D7-brane, and connected by T-duality to other exotic branes in Type IIA: the KK-6A

  9. D-brane categories

    OpenAIRE

    Lazaroiu, C. I.

    2003-01-01

    This is an exposition of recent progress in the categorical approach to D-brane physics. I discuss the physical underpinnings of the appearance of homotopy categories and triangulated categories of D-branes from a string field theoretic perspective, and with a focus on applications to homological mirror symmetry.

  10. Branes and wrapping rules

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Riccioni, F.

    We show that the solitonic branes of ten-dimensional IIA/IIB string theory must satisfy, upon toroidal compactification, a specific wrapping rule in order to reproduce the number of half-supersymmetric solitonic branes that follows from a supergravity analysis. The realization of this wrapping rule

  11. On D-brane dynamics and moduli stabilization

    Science.gov (United States)

    Kitazawa, Noriaki

    2017-09-01

    We discuss the effect of the dynamics of D-branes on moduli stabilization in type IIB string theory compactifications, with reference to a concrete toy model of T6/Z 3 orientifold compactification with fractional D3-branes and anti-D3-branes at orbifold fixed points. The resulting attractive forces between anti-D3-branes and D3-branes, together with the repulsive forces between anti-D3-branes and O3-planes, can affect the stability of the compact space. There are no complex structure moduli in T6/Z 3 orientifold, which should thus capture some generic features of more general settings where all complex structure moduli are stabilized by three-form fluxes. The simultaneous presence of branes and anti-branes brings along the breaking of supersymmetry. Non-BPS combinations of this type are typical of “brane supersymmetry breaking” and are a necessary ingredient in the KKLT scenario for stabilizing the remaining Kähler moduli. The conclusion of our analysis is that, while mutual D-brane interactions sometimes help Kähler moduli stabilization, this is not always the case.

  12. Q-branes [Non-topological solitons (Q-balls) are discussed in some stringy settings

    Energy Technology Data Exchange (ETDEWEB)

    Abel, Steven [Institute for Particle Physics Phenomenology, University of Durham,South Road, Durham, DH1 3LE (United Kingdom); Kehagias, Alex [Physics Dept., National Technical University,157 80 Zografou, Athens (Greece)

    2015-11-16

    Non-topological solitons (Q-balls) are discussed in some stringy settings. Our main result is that the dielectric D-brane system of Myers admits non-abelian Q-ball solutions on their world-volume, in which N Dp-branes relax to the standard dielectric form outside the Q-ball, but assume a more diffuse configuration at its centre. We also consider how Q-balls behave in the bulk of extra-dimensional theories, or on wrapped branes. We demonstrate that they carry Kaluza-Klein charge and possess a corresponding Kaluza-Klein tower of states just as normal particles, and we discuss surface energy effects by finding exact Q-ball solutions in models with a specific logarithmic potential.

  13. D=4 Chiral String Compactifications from Intersecting Branes

    CERN Document Server

    Aldazabal, G.; Ibanez, Luis E.; Rabadan, R.; Uranga, A.M.

    2001-01-01

    Intersecting Dp-branes often give rise to chiral fermions living on their intersections. We study the construction of four-dimensional chiral theories by considering configurations of type II D(3+n)-branes wrapped on non-trivial n-cycles on T^{2n} x R^{2(3-n)}/Z_N, for $n=1,2,3$. The gauge theories on the four non-compact dimensions of the brane world-volume are generically chiral and non-supersymmetric. We analyze consistency conditions (RR tadpole cancellation) for these models, and their relation to four-dimensional anomaly cancellation. Cancellation of U(1) gauge anomalies involves a Green-Schwarz mechanism mediated by RR partners of untwisted and/or twisted moduli. This class of models is of potential phenomenological interest, and we construct explicit examples of SU(3) x SU(2) x U(1) three-generation models. The models are non-supersymmetric, but the string scale may be lowered close to the weak scale so that the standard hierarchy problem is avoided. We also comment on the presence of scalar tachyons ...

  14. Cosmology from quantum potential in a system of oscillating branes

    OpenAIRE

    Sepehri, Alireza

    2015-01-01

    Recently, some authors proposed a new mechanism which gets rid of the big-bang singularity and shows that the age of the universe is infinite. In this paper, we will confirm their results and predict that the universe may expand and contract many times in a system of oscillating branes. In this model, first, N fundamental strings transit to N M0-anti-M0-branes. Then, M0-branes join to each other and build an M8-anti-M8 system. This system is unstable, broken and two anti-M4-branes, a compacti...

  15. The gravity of dark vortices: effective field theory for branes and strings carrying localized flux

    Science.gov (United States)

    Burgess, C. P.; Diener, R.; Williams, M.

    2015-11-01

    A Nielsen-Olesen vortex usually sits in an environment that expels the flux that is confined to the vortex, so flux is not present both inside and outside. We construct vortices for which this is not true, where the flux carried by the vortex also permeates the `bulk' far from the vortex. The idea is to mix the vortex's internal gauge flux with an external flux using off-diagonal kinetic mixing. Such `dark' vortices could play a phenomenological role in models with both cosmic strings and a dark gauge sector. When coupled to gravity they also provide explicit ultra-violet completions for codimension-two brane-localized flux, which arises in extra-dimensional models when the same flux that stabilizes extra-dimensional size is also localized on space-filling branes situated around the extra dimensions. We derive simple formulae for observables such as defect angle, tension, localized flux and on-vortex curvature when coupled to gravity, and show how all of these are insensitive to much of the microscopic details of the solutions, and are instead largely dictated by low-energy quantities. We derive the required effective description in terms of a world-sheet brane action, and derive the matching conditions for its couplings. We consider the case where the dimensions transverse to the bulk compactify, and determine how the on- and off-vortex curvatures and other bulk features depend on the vortex properties. We find that the brane-localized flux does not gravitate, but just renormalizes the tension in a magnetic-field independent way. The existence of an explicit UV completion puts the effective description of these models on a more precise footing, verifying that brane-localized flux can be consistent with sensible UV physics and resolving some apparent paradoxes that can arise with a naive (but commonly used) delta-function treatment of the brane's localization within the bulk.

  16. Thermodynamics of anisotropic branes

    Energy Technology Data Exchange (ETDEWEB)

    Ávila, Daniel [Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, A.P. 70-542, México D.F. 04510 (Mexico); Fernández, Daniel [Max-Planck-Institut für Physik,Föhringer Ring 6, 80805 München (Germany); Patiño, Leonardo [Departamento de Física, Facultad de Ciencias, Universidad Nacional Autónoma de México, A.P. 70-542, México D.F. 04510 (Mexico); Trancanelli, Diego [Institute of Physics, University of São Paulo,05314-970 São Paulo (Brazil)

    2016-11-22

    We study the thermodynamics of flavor D7-branes embedded in an anisotropic black brane solution of type IIB supergravity. The flavor branes undergo a phase transition between a ‘Minkowski embedding’, in which they lie outside of the horizon, and a ‘black hole embedding’, in which they fall into the horizon. This transition depends on the black hole temperature, its degree of anisotropy, and the mass of the flavor degrees of freedom. It happens either at a critical temperature or at a critical anisotropy. A general lesson we learn from this analysis is that the anisotropy, in this particular realization, induces similar effects as the temperature. In particular, increasing the anisotropy bends the branes more and more into the horizon. Moreover, we observe that the transition becomes smoother for higher anisotropies.

  17. The Physics of Branes

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. The Physics of Branes. Sunil Mukhi, Tata Institute of Fundamental Research; Annual Meeting, Indian Academy of Sciences; Chandigarh, November 2002. Notes:

  18. Non-extremal branes

    Directory of Open Access Journals (Sweden)

    Pablo Bueno

    2015-04-01

    Full Text Available We prove that for arbitrary black brane solutions of generic Supergravities there is an adapted system of variables in which the equations of motion are exactly invariant under electric–magnetic duality, i.e. the interchange of a given extended object by its electromagnetic dual. We obtain thus a procedure to automatically construct the electromagnetic dual of a given brane without needing to solve any further equation. We apply this procedure to construct the non-extremal (p,q-string of Type-IIB String Theory (new in the literature, explicitly showing how the dual (p,q-five-brane automatically arises in this construction. In addition, we prove that the system of variables used is suitable for a generic characterization of every double-extremal Supergravity brane solution, which we perform in full generality.

  19. D-brane anti-D-brane system in string theory

    CERN Document Server

    Hyakutake, Y

    2003-01-01

    In this paper, we review a system of D-brane and anti-D-brane in type II superstring theories. [A. Sen, hep-th/9904207 and references there in; Y.Hyakutake, Master-Th., Doctor-Th. (in Japanese)] This system is unstable an tachyonic modes, which have negative mass squared, appear from open strings between D-brane and anti-D-brane. The effective field theory on the world-volume is described by U(1) x U(1) gauge theory with a complex tachyon field. Since the mass squared of the techyon field is negative, a tachyon potential would be like a wine bottle. In order to make the system stable, the tachyon rolls down the potential and gets some vacuum expectation value. This is called the tachyon condensation mechanism. During this mechanism, Dp-brane and anti-Dp-brane annihilate completely, if we admit Sen's conjecture. The suspicions between tachyon condensation and Hawking radiation are also discussed. (author)

  20. Manual of BlackMax, a black-hole event generator with rotation, recoil, split branes, and brane tension

    OpenAIRE

    Dai, De-Chang; Issever, Cigdem; Rizvi, Eram; Starkman, Glenn; Stojkovic, Dejan; Tseng, Jeff

    2009-01-01

    This is the users manual of the black-hole event generator BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at proton-proton, proton-antiproton and electron-positron colliders in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity. It includes all of the black-hole gray-body factors known to dat...

  1. Probing the partially localized supergravity background of the fundamental string ending on the Dp-brane

    CERN Document Server

    Youm, Donam

    2000-01-01

    We study the dynamics of the probe fundamental string in the field background of the partially localized supergravity solution for the fundamental string ending on the Dp-brane. We separately analyze the probe dynamics for its motion along the world volume direction and the transverse direction of the source Dp-brane. We compare the dynamics of the probe along the Dp-brane world volume direction to the bion dynamics.

  2. Effect of the chameleon scalar field on brane cosmological evolution

    Directory of Open Access Journals (Sweden)

    Y. Bisabr

    2017-11-01

    Full Text Available We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.

  3. Effect of the chameleon scalar field on brane cosmological evolution

    Science.gov (United States)

    Bisabr, Y.; Ahmadi, F.

    2017-11-01

    We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.

  4. Bulk fields with brane terms

    Energy Technology Data Exchange (ETDEWEB)

    Aguila, F. del [Departamento de Fisica Teorica y del Cosmos and Centro Andaluz de Fisica de Particulas Elementales (CAFPE), Universidad de Granada, E-18071 Granada (Spain); Perez-Victoria, M. [Dipartimento di Fisica ' ' G. Galilei' ' , Universita di Padova and INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padua (Italy); Santiago, J. [Institute for Particle Physics Phenomenology, University of Durham, South Road, Durham DH1 3LE (United Kingdom)

    2004-07-01

    In theories with branes, bulk fields get in general divergent corrections localized on these defects. Hence, the corresponding brane terms are renormalized and should be included in the effective theory from the very beginning. We review the phenomenology associated to brane kinetic terms for different spins and backgrounds, and point out that renormalization is required already at the classical level. (orig.)

  5. Mirror symmetry in the presence of branes

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, Adrian

    2011-10-11

    This work deals with mirror symmetry for N=1 compactifications on compact Calabi-Yau threefolds with branes. The mayor tool is a combined deformation space for the Calabi-Yau and a hypersurface within it. Periods of this deformation space contain information about B-type branes within the hypersurface in addition to the usual closed string data. To study these periods we generalize techniques used in closed string mirror symmetry. We derive the Picard-Fuchs system and encode the information in extended toric polytopes. Solutions of the Picard-Fuchs equations give superpotentials for certain brane configurations. This is an efficient way to calculate superpotentials. The deformations we consider are massive for all branes with non trivial superpotential. Depending on a choice of a family of hypersurfaces, the superpotential of the effective low energy theory depends on different massive fields. A priori there is no reason for these fields to be lighter then other fields that are not included. We find however examples where the superpotential is nearly at. In these examples we use the Gauss-Manin connection on the combined deformation space to define an open string mirror map. We find instanton generated superpotentials of A-type branes. This gives predictions for Ooguri-Vafa invariants counting holomorphic disks that end on a Lagrangian brane on the Quintic. A second class of examples does not have preferred nearly massless deformations and different families of hypersurfaces can be used to calculate the same on-shell superpotential. We calculate examples of superpotentials for branes in Calabi-Yau manifolds with several moduli. The on-shell superpotentials are mapped to the mirror A-model to study the instanton expansion and to obtain predictions for disk invariants. The combined deformation spaces are equivalent to the quantum corrected Kaehler deformation spaces of certain non compact Calabi-Yau fourfolds. These fourfolds are fibrations of Calabi-Yau threefolds

  6. Inflation and Brane Gases

    OpenAIRE

    Brandenberger, Robert; Easson, Damien A.; Mazumdar, Anupam

    2003-01-01

    We investigate a new way of realizing a period of cosmological inflation in the context of brane gas cosmology. It is argued that a gas of co-dimension one branes, out of thermal equilibrium with the rest of the matter, has an equation of state which can - after stabilization of the dilaton - lead to power-law inflation of the bulk. The most promising implementation of this mechanism might be in Type IIB superstring theory, with inflation of the three large spatial dimensions triggered by ``s...

  7. Brane Bremsstrahlung in DBI Inflation

    CERN Document Server

    Brax, Philippe

    2010-01-01

    We consider the effect of trapped branes on the evolution of a test brane whose motion generates DBI inflation along a warped throat. The coupling between the inflationary brane and a trapped brane leads to the radiation of non-thermal particles on the trapped brane. We calculate the Gaussian spectrum of the radiated particles and their backreaction on the DBI motion of the inflationary brane. Radiation occurs for momenta lower than the speed of the test brane when crossing the trapped brane. The slowing down effect is either due to a parametric resonance when the interaction time is small compared to the Hubble time or a tachyonic resonance when the interaction time is large. In both cases the motion of the inflationary brane after the interaction is governed by a chameleonic potential,which tends to slow it down. We find that a single trapped brane can hardly slow down a DBI inflaton whose fluctuations lead to the Cosmic Microwave Background spectrum. A more drastic effect is obtained when the DBI brane enc...

  8. The gravity of dark vortices: effective field theory for branes and strings carrying localized flux

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, C.P. [Physics & Astronomy, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, ON, N2L 2Y5 (Canada); Division PH -TH, CERN, CH-1211, Genève 23 (Switzerland); Diener, R. [Physics & Astronomy, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, ON, N2L 2Y5 (Canada); Williams, M. [Instituut voor Theoretische Fysica, Katholieke Universiteit Leuven, B-3001 Leuven (Belgium)

    2015-11-06

    A Nielsen-Olesen vortex usually sits in an environment that expels the flux that is confined to the vortex, so flux is not present both inside and outside. We construct vortices for which this is not true, where the flux carried by the vortex also permeates the ‘bulk’ far from the vortex. The idea is to mix the vortex’s internal gauge flux with an external flux using off-diagonal kinetic mixing. Such ‘dark’ vortices could play a phenomenological role in models with both cosmic strings and a dark gauge sector. When coupled to gravity they also provide explicit ultra-violet completions for codimension-two brane-localized flux, which arises in extra-dimensional models when the same flux that stabilizes extra-dimensional size is also localized on space-filling branes situated around the extra dimensions. We derive simple formulae for observables such as defect angle, tension, localized flux and on-vortex curvature when coupled to gravity, and show how all of these are insensitive to much of the microscopic details of the solutions, and are instead largely dictated by low-energy quantities. We derive the required effective description in terms of a world-sheet brane action, and derive the matching conditions for its couplings. We consider the case where the dimensions transverse to the bulk compactify, and determine how the on- and off-vortex curvatures and other bulk features depend on the vortex properties. We find that the brane-localized flux does not gravitate, but just renormalizes the tension in a magnetic-field independent way. The existence of an explicit UV completion puts the effective description of these models on a more precise footing, verifying that brane-localized flux can be consistent with sensible UV physics and resolving some apparent paradoxes that can arise with a naive (but commonly used) delta-function treatment of the brane’s localization within the bulk.

  9. Born–Infeld extension of Lovelock brane gravity in the system of M0-branes and its application for the emergence of Pauli exclusion principle in BIonic superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)

    2016-07-01

    Recently, some authors (Cruz and Rojas, 2013 [1]) have constructed a Born–Infeld type action which may be written in terms of the Lovelock brane Lagrangians for a given dimension p. We reconsider their model in M-theory and study the process of birth and growth of nonlinear spinor and bosonic gravity during the construction of Mp-branes. Then, by application of this idea to BIonic system, we construct a BIonic superconductor in the background of nonlinear gravity. In this model, first, M0-branes link to each other and build an M5-brane and an anti-M5-brane connected by an M2-brane. M0-branes are zero dimensional objects that only scalars are attached to them. By constructing higher dimensional branes from M0-branes, gauge fields are produced. Also, if M0-branes don't link to each other completely, the symmetry of system is broken and fermions are created. The curvature produced by fermions has the opposite sign the curvature produced by gauge fields. Fermions on M5-branes and M2 plays the role of bridge between them. By passing time, M2 dissolves in M5's and nonlinear bosonic and spinor gravities are produced. By closing M5-branes towards each other, coupling of two identical fermions on two branes to each other causes that the square mass of their system becomes negative and some tachyonic states are created. For removing these tachyons, M5-branes compact, the sign of gravity between branes reverses, anti-gravity is produced which causes that branes and identical fermions get away from each other. This is the reason for the emergence of Pauli exclusion principle in Bionic system. Also, the spinor gravity vanishes and its energy builds a new M2 between M5-branes. We obtain the resistivity in this system and find that its value decreases by closing M5 branes to each other and shrinks to zero at colliding point of branes. This idea has different applications. For example, in cosmology, universes are located on M5-branes and M2-brane has the role of bridge

  10. Brane Bounce from logarithmic entropic corrections in the bulk

    CERN Document Server

    Addazi, Andrea

    2016-01-01

    We calculate new corrections to the Brane-world dynamics, lying in a 5D Schwarzschild-De Sitter black hole, generalizing the result of Nojiri, Odintsov and Ogushi (NOO) in Ref.\\cite{Nojiri:2002vu}, The NOO entropy effect is based on the Logharitmic correction to the bulk entropy firstly calculated by Mukherji and Pal in Ref.\\cite{Mukherji:2002de}. We calculate higher order contributions to the brane worldsheet. The extra terms obtained lead to interesting implications in brane-cosmology. In particular, new entropic terms rapidly disappear in the late Universe while exploding in the very Early Universe. In particular, we show that they may trigger a cosmological bounce in the very early Universe. On the other hand, they contribute to the cosmological expansion in the Late Universe. We also discuss a scenario in which the BLK anisotropies are washed-out, toward a new Ekpyrotic Brane Cosmology.

  11. Effect of bulk Lorentz violation on anisotropic brane cosmologies

    Science.gov (United States)

    Heydari-Fard, Malihe

    2012-04-01

    The effect of Lorentz invariance violation in cosmology has attracted a considerable amount of attention. By using a dynamical vector field assumed to point in the bulk direction, with Lorentz invariance holding on the brane, we extend the notation of Lorentz violation in four dimensions Jacobson to a five-dimensional brane-world. We obtain the general solution of the field equations in an exact parametric form for Bianchi type I space-time, with perfect fluid as a matter source. We show that the brane universe evolves from an isotropic/anisotropic state to an isotropic de Sitter inflationary phase at late time. The early time behavior of anisotropic brane universe is largely dependent on the Lorentz violating parameters βi,i = 1,2,3 and the equation of state of the matter, while its late time behavior is independent of these parameters.

  12. A 5D holographic dark energy in DGP-BRANE cosmology

    Science.gov (United States)

    Farajollahi, H.; Ravanpak, A.

    2014-02-01

    This paper is aimed to investigate 5D holographic dark energy (HDE) in DGP-Brane cosmology by employing a combination of Sne Ia, BAO and CMB observational data and constraining cosmological parameters. The FRW dynamics for the normal branch ( ɛ=+1) solution of induced gravity brane-world model is taken with the assumption that matter in 5D bulk is HDE such that its holographic nature is reproduced effectively in 4D universe. In the HDE model, we used Hubble horizon as IR cutoff instead of future event horizon. This way, while the model predicts current universe acceleration, it also removes the problem of circular reasoning and causality observed in using future event horizon as IR cutoff.

  13. Domain walls and spacetime-filling branes

    NARCIS (Netherlands)

    Bergshoeff, E; Wess, J; Ivanov, EA

    1999-01-01

    We discuss branes with one transversal direction (domain walls) and no transversal direction (spacetime-filling branes). In particular, we briefly discuss a relationship between spacetime-filling branes and superstring theories with sixteen supercharges.

  14. A Gauged Open 2-Brane String in the p-Brane Background

    Directory of Open Access Journals (Sweden)

    Fahimeh Sarvi

    2016-01-01

    Full Text Available We make a gauge theory from the Open p-brane system and map it into the Open 2-Brane one. Due to the presence of second-class constraints in this model, we encounter some problems during the procedure of quantization. In this regard, considering boundary conditions as Dirac conditions, one can drive the constrained structure of the model at first. Then, with the help of BFT formalism of constraint systems, the Open 2-Brane model is embedded into an extended phase space. For this purpose, we introduce some tensor fields to convert ungauged theory into the gauged one. This is the novel part of our research, while mostly scalar and vector fields are used to convert second-class constraints into first ones.

  15. D6-brane model building on Z2×Z6: MSSM-like and left–right symmetric models

    Directory of Open Access Journals (Sweden)

    Jill Ecker

    2015-12-01

    Full Text Available We perform a systematic search for globally defined MSSM-like and left–right symmetric models on D6-branes on the T6/(Z2×Z6×ΩR orientifold with discrete torsion. Our search is exhaustive for models that are independent of the value of the one free complex structure modulus. Preliminary investigations suggest that there exists one prototype of visible sector for MSSM-like and another for left–right symmetric models with differences arising from various hidden sector completions to global models. For each prototype, we provide the full matter spectrum, as well as the Yukawa and other three-point couplings needed to render vector-like matter states massive. This provides us with tentative explanations for the mass hierarchies within the quark and lepton sectors. We also observe that the MSSM-like models correspond to explicit realisations of the supersymmetric DFSZ axion model, and that the left–right symmetric models allow for global completions with either completely decoupled hidden sectors or with some messenger states charged under both visible and hidden gauge groups.

  16. Bending branes for DCFT in two dimensions

    Science.gov (United States)

    Erdmenger, Johanna; Flory, Mario; Newrzella, Max-Niklas

    2015-01-01

    We consider a holographic dual model for defect conformal field theories (DCFT) in which we include the backreaction of the defect on the dual geometry. In particular, we consider a dual gravity system in which a two-dimensional hypersurface with matter fields, the brane, is embedded into a three-dimensional asymptotically Anti-de Sitter spacetime. Motivated by recent proposals for holographic duals of boundary conformal field theories (BCFT), we assume the geometry of the brane to be determined by Israel junction conditions. We show that these conditions are intimately related to the energy conditions for the brane matter fields, and explain how these energy conditions constrain the possible geometries. This has implications for the holographic entanglement entropy in particular. Moreover, we give exact analytical solutions for the case where the matter content of the brane is a perfect fluid, which in a particular case corresponds to a free massless scalar field. Finally, we describe how our results may be particularly useful for extending a recent proposal for a holographic Kondo model.

  17. Born-Infeld extension of Lovelock brane gravity in the system of M0-branes and its application for the emergence of Pauli exclusion principle in BIonic superconductors

    Science.gov (United States)

    Sepehri, Alireza

    2016-07-01

    Recently, some authors (Cruz and Rojas, 2013 [1]) have constructed a Born-Infeld type action which may be written in terms of the Lovelock brane Lagrangians for a given dimension p. We reconsider their model in M-theory and study the process of birth and growth of nonlinear spinor and bosonic gravity during the construction of Mp-branes. Then, by application of this idea to BIonic system, we construct a BIonic superconductor in the background of nonlinear gravity. In this model, first, M0-branes link to each other and build an M5-brane and an anti-M5-brane connected by an M2-brane. M0-branes are zero dimensional objects that only scalars are attached to them. By constructing higher dimensional branes from M0-branes, gauge fields are produced. Also, if M0-branes don't link to each other completely, the symmetry of system is broken and fermions are created. The curvature produced by fermions has the opposite sign the curvature produced by gauge fields. Fermions on M5-branes and M2 plays the role of bridge between them. By passing time, M2 dissolves in M5's and nonlinear bosonic and spinor gravities are produced. By closing M5-branes towards each other, coupling of two identical fermions on two branes to each other causes that the square mass of their system becomes negative and some tachyonic states are created. For removing these tachyons, M5-branes compact, the sign of gravity between branes reverses, anti-gravity is produced which causes that branes and identical fermions get away from each other. This is the reason for the emergence of Pauli exclusion principle in Bionic system. Also, the spinor gravity vanishes and its energy builds a new M2 between M5-branes. We obtain the resistivity in this system and find that its value decreases by closing M5 branes to each other and shrinks to zero at colliding point of branes. This idea has different applications. For example, in cosmology, universes are located on M5-branes and M2-brane has the role of bridge between

  18. Running with rugby balls: bulk renormalization of codimension-2 branes

    Science.gov (United States)

    Williams, M.; Burgess, C. P.; van Nierop, L.; Salvio, A.

    2013-01-01

    We compute how one-loop bulk effects renormalize both bulk and brane effective interactions for geometries sourced by codimension-two branes. We do so by explicitly integrating out spin-zero, -half and -one particles in 6-dimensional Einstein-Maxwell-Scalar theories compactified to 4 dimensions on a flux-stabilized 2D geometry. (Our methods apply equally well for D dimensions compactified to D - 2 dimensions, although our explicit formulae do not capture all divergences when D > 6.) The renormalization of bulk interactions are independent of the boundary conditions assumed at the brane locations, and reproduce standard heat-kernel calculations. Boundary conditions at any particular brane do affect how bulk loops renormalize this brane's effective action, but not the renormalization of other distant branes. Although we explicitly compute our loops using a rugby ball geometry, because we follow only UV effects our results apply more generally to any geometry containing codimension-two sources with conical singularities. Our results have a variety of uses, including calculating the UV sensitivity of one-loop vacuum energy seen by observers localized on the brane. We show how these one-loop effects combine in a surprising way with bulk back-reaction to give the complete low-energy effective cosmological constant, and comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.

  19. Black holes in realistic branes: Black string-like objects?

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Instituto de Física, Universidade de São Paulo, 05314-970, São Paulo, SP (Brazil); Departamento de Física, Universidade Federal da Paraíba, 58051-970, João Pessoa, PB (Brazil); Hoff da Silva, J.M., E-mail: hoff@feg.unesp.br [Departamento de Física e Química, Universidade Estadual Paulista, Av. Dr. Ariberto Pereira da Cunha, 333, Guaratinguetá, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC (UFABC), 09210-170, Santo André, SP (Brazil)

    2013-04-25

    A realistic model describing a black string-like object in an expanding Universe is analyzed in the context of the McVittie's solution of the Einstein field equations. The bulk metric near the brane is provided analogously to previous solutions for black strings. In particular, we show that at least when the Hubble parameter on the brane is positive, a black string-like object seems to play a fundamental role in the braneworld scenario, generalizing the standard black strings in the context of a dynamical brane.

  20. P fluxes and exotic branes

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Davide M. [Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); Risoli, Stefano [Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-12-21

    We consider the N=1 superpotential generated in type-II orientifold models by non-geometric fluxes. In particular, we focus on the family of P fluxes, that are related by T-duality transformations to the S-dual of the Q flux. We determine the general rule that transforms a given flux in this family under a single T-duality transformation. This rule allows to derive a complete expression for the superpotential for both the IIA and the IIB theory for the particular case of a T{sup 6}/[ℤ{sub 2}×ℤ{sub 2}] orientifold. We then consider how these fluxes modify the generalised Bianchi identities. In particular, we derive a fully consistent set of quadratic constraints coming from the NS-NS Bianchi identities. On the other hand, the P flux Bianchi identities induce tadpoles, and we determine a set of exotic branes that can be consistently included in order to cancel them. This is achieved by determining a universal transformation rule under T-duality satisfied by all the branes in string theory.

  1. Brane singularities and their avoidance in a fluid bulk

    CERN Document Server

    Antoniadis, Ignatios; Klaoudatou, Ifigeneia

    2010-01-01

    Using the method of asymptotic splittings, the possible singularity structures and the corresponding asymptotic behavior of a 3-brane in a five-dimensional bulk are classified, in the case where the bulk field content is parametrized by an analog of perfect fluid with an arbitrary equation of state $P=\\gamma\\rho$ between the `pressure' $P$ and the `density' $\\rho$. In this analogy with homogeneous cosmologies, the time is replaced by the extra coordinate transverse to the 3-brane, whose world-volume can have an arbitrary constant curvature. The results depend crucially on the constant parameter $\\gamma$: (i) For $\\gamma>-1/2$, the flat brane solution suffers from a collapse singularity at finite distance, that disappears in the curved case. (ii) For $\\gamma<-1$, the singularity cannot be avoided and it becomes of the type big rip for a flat brane. (iii) For $-1<\\gamma\\le -1/2$, the surprising result is found that while the curved brane solution is singular, the flat brane is not, opening the possibility...

  2. Freezing E3-brane instantons with fluxes

    CERN Document Server

    Bianchi, Massimo; Martucci, Luca

    2012-01-01

    E3-instantons that generate non-perturbative superpotentials in IIB N=1 compactifications are more frequent than currently believed. Worldvolume fluxes will typically lift the E3-brane geometric moduli and their fermionic superpartners, leaving only the two required universal fermionic zero-modes. We consistently incorporate SL(2, Z) monodromies and world-volume fluxes in the effective theory of the E3-brane fermions and study the resulting zero-mode spectrum, highlighting the relation between F-theory and perturbative IIB results. This leads us to a IIB derivation of the index for generation of superpotential terms, which reproduces and generalizes available results. Furthermore, we show how worldvolume fluxes can be explicitly constructed in a one-modulus compactification, such that an E3-instanton has exactly two fermonic zero-modes. This construction is readily applicable to numerous scenarios.

  3. Emergence and oscillation of cosmic space by joining M1-branes

    Energy Technology Data Exchange (ETDEWEB)

    Sepehri, Alireza [Shahid Bahonar University, Faculty of Physics, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Rahaman, Farook [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Capozziello, Salvatore [Universita di Napoli Federico II, Dipartimento di Fisica ' ' E. Pancini' ' , Naples (Italy); Gran Sasso Science Institute (INFN), L' Aquila (Italy); Tomsk State Pedagogical University, Tomsk (Russian Federation); INFN Sezione di Napoli, Naples (Italy); Ali, Ahmed Farag [Benha University, Department of Physics, Faculty of Science, Benha (Egypt); Pradhan, Anirudh [G L A University, Department of Mathematics, Institute of Applied Sciences and Humanities, Mathura, Uttar Pradesh (India)

    2016-05-15

    Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural question arises; how could this model explain the oscillation of the universe between contraction and expansion branches? We try to address this issue in the framework of a BIonic system. In this model, M0-branes join to each other and give rise to a pair of M1-anti-M1-branes. The fields which live on these branes play the roles of massive gravitons that cause the emergence of a wormhole between them and formation of a BIon system. This wormhole dissolves into M1-branes and causes a divergence between the number of degrees of freedom on the boundary surface of M1 and the bulk leading to an expansion of M1-branes. When M1-branes become close to each other, the square energy of their system becomes negative and some tachyonic states emerge. To remove these states, M1-branes become compact, the sign of compacted gravity changes, causing anti-gravity to arise: in this case, branes get away from each other. By articulating M1-BIons, an M3-brane and an anti-M3-brane are created and connected by three wormholes forming an M3-BIon. This new system behaves like the initial system and by closing branes to each other, they become compact and, by getting away from each other, they open. Our universe is located on one of these M3-branes and, by compactifying the M3-brane, it contracts and, by opening it, it expands. (orig.)

  4. On D-brane anti D-brane effective actions and their corrections to all orders in alpha-prime

    CERN Document Server

    Hatefi, Ehsan

    2013-09-09

    Based on a four point function, the S-matrix elements at disk level of the scattering amplitude of one closed string Ramond-Ramond field ($C$) and two tachyons and one scalar field, we find out new couplings in brane anti brane effective actions for $p=n,p+2=n$ cases. Using the infinite corrections of the vertex of one RR, one gauge and one scalar field and applying the correct expansion, it is investigated in details how we produce the infinite gauge poles of the amplitude for $p = n$ case. By discovering new higher derivative corrections of two tachyon-two scalar couplings in brane anti brane systems to all orders in $\\alpha'$, we also obtain the infinite scalar poles in $t'+s'+u$-channel in field theory. Working with the complete form of the amplitude with the closed form of the expansion and comparing all the infinite contact terms of this amplitude, we derive several new Wess-Zumino couplings with all their infinite higher derivative corrections in the world volume of brane anti brane systems. In particu...

  5. Domain walls on the brane

    NARCIS (Netherlands)

    Bergshoeff, E; van der Schaar, JP; Papadopoulos, G

    1998-01-01

    We show that all branes admit worldvolume domain wall solutions. We find one class of solutions for which the tension of the brane changes discontinuously along the domain wall. These solutions are not supersymmetric. We argue that there is another class of domain wall solutions which is

  6. Solitonic branes and wrapping rules

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Riccioni, Fabio

    We show that the solitonic branes of ten-dimensional IIA/IIB string theory must satisfy, upon toroidal compactification, a specific wrapping rule in order to reproduce the number of half-supersymmetric solitonic branes that follows from a supergravity analysis. The realization of this wrapping rule

  7. Brane bounce-type configurations in a string-like scenario

    Science.gov (United States)

    Sousa, L. J. S.; Silva, C. A. S.; Almeida, C. A. S.

    2012-12-01

    Brane world six-dimensional scenario with string-like metric has been proposed to alleviate the problem of field localization. However, these models have been suffering from some drawbacks related with energy conditions as well as from difficulties to find analytical solutions. In this work, we propose a model where a brane is made of a scalar field with bounce-type configurations and embedded in a bulk with a string-like metric. This model produces a sound AdS scenario where none of the important physical quantities is infinite. Among these quantities are the components of the energy-momentum tensor, which have its positivity ensured by a suitable choice of the bounce configurations. Another advantage of this model is that the warp factor can be obtained analytically from the equations of motion for the scalar field, obtaining as a result a thick brane configuration, in a six-dimensional context. Moreover, the study of the scalar field localization in this scenario is done.

  8. Brane classical and quantum cosmology from an effective action

    Science.gov (United States)

    Seahra, Sanjeev S.; Sepangi, H. R.; Ponce de Leon, J.

    2003-09-01

    Motivated by the Randall-Sundrum braneworld scenario, we discuss the classical and quantum dynamics of a (d+1)-dimensional boundary wall between a pair of (d+2)-dimensional topological Schwarzschild-AdS black holes. We assume there are quite general—but not completely arbitrary—matter fields living on the boundary “brane universe,” and that its geometry is that of a Friedmann-Lemaître-Robertson-Walker (FLRW) model. The effective action governing the model in the minisuperspace approximation is derived. We find that the presence of black hole horizons in the bulk gives rise to a complex action for certain classically allowed brane configurations, but that the imaginary contribution plays no role in the equations of motion. Classical and instanton brane trajectories are examined in general and for special cases, and we find a subset of configuration space that is not allowed at the classical or semiclassical level; this subset corresponds to spacelike branes carrying tachyonic matter. The Hamiltonization and Dirac quantization of the model is then performed for the general case; the latter involves the manipulation of the Hamiltonian constraint before it is transformed into an operator that annihilates physical state vectors. The ensuing covariant Wheeler-DeWitt equation is examined at the semiclassical level, and we consider the possible localization of the brane universe’s wave function away from the cosmological singularity. This is easier to achieve for branes with low density and/or spherical spatial sections.

  9. Unstoppable brane-flux decay of (D6)-bar branes

    Energy Technology Data Exchange (ETDEWEB)

    Danielsson, UniversityH. [Institutionen för Fysik och Astronomi, Uppsala Universitet, Uppsala (Sweden); Gautason, F.F. [Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Riet, T. Van [Instituut voor Theoretische Fysica, K.University Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)

    2017-03-27

    We investigate p (D6)-bar branes inside a flux throat that carries K×M D6 charges with K the 3-form flux quantum and M the Romans mass. In such a setup brane-flux annihilation can proceed through the nucleation of KK5 branes. We find that within the calculable supergravity regime where g{sub s}p is large, the (D6)-bar branes annihilate immediately against the fluxes despite the existence of a metastable state at small p/M in the probe approximation. The crucial property that causes this naive conflict with effective field theory is a singularity in the 3-form flux, which we cut off at string scale. Our result explains the absence of regular solutions at finite temperature and suggests there should be a smooth time-dependent solution. We also discuss the qualitative differences between (D6)-bar branes and (D3)-bar branes, which makes it a priori not obvious to conclude the same instability for (D3)-bar branes.

  10. Heterotic M2-branes

    Directory of Open Access Journals (Sweden)

    Neil Lambert

    2015-10-01

    Full Text Available We construct the action for N M2-branes on S1/Z2. The resulting theory has a gauge anomaly but this can be cancelled if the two fixed point planes each support 8 chiral Fermions in the fundamental of U(N. Taking the low energy limit leads to the worldsheet theory of N free heterotic strings whose quantization induces an E8 spacetime gauge symmetry on each fixed point plane. Thus this paper presents a non-abelian worldvolume analogue of the classic Hořava–Witten analysis.

  11. Two-brane system in a vacuum bulk with a single equation of state

    CERN Document Server

    Perez, Juan L; Urena-Lopez, L Arturo; 10.1063/1.4748545

    2012-01-01

    We study the cosmology of a two-brane model in a five-dimensional spacetime, where the extra spatial coordinate is compactifed on an orbifold. Additionally, we consider the existence on each brane of matter fields that evolve in time. Solving the Einstein equations in a vacuum bulk, we can show how the matter fields in both branes are connected and they do not evolve independently

  12. Null-wave giant gravitons from thermal spinning brane probes

    Science.gov (United States)

    Armas, Jay; Obers, Niels A.; Pedersen, Andreas Vigand

    2013-10-01

    We construct and analyze thermal spinning giant gravitons in type II/M-theory based on spherically wrapped black branes, using the method of thermal probe branes originating from the blackfold approach. These solutions generalize in different directions recent work in which the case of thermal (non-spinning) D3-brane giant gravitons was considered, and reveal a rich phase structure with various new properties. First of all, we extend the construction to M-theory, by constructing thermal giant graviton solutions using spherically wrapped M2- and M5-branes. More importantly, we switch on new quantum numbers, namely internal spins on the sphere, which are not present in the usual extremal limit for which the brane world volume stress tensor is Lorentz invariant. We examine the effect of this new type of excitation and in particular analyze the physical quantities in various regimes, including that of small temperatures as well as low/high spin. As a byproduct we find new stationary dipole-charged black hole solutions in AdS m × S n backgrounds of type II/M-theory. We finally show, via a double scaling extremal limit, that our spinning thermal giant graviton solutions lead to a novel null-wave zero-temperature giant graviton solution with a BPS spectrum, which does not have an analogue in terms of the conventional weakly coupled world volume theory.

  13. Intersecting flavor branes

    Science.gov (United States)

    Pomoni, Elli; Rastelli, Leonardo

    2012-10-01

    We consider an instance of the AdS/CFT duality where the bulk theory contains an open string tachyon, and study the instability from the viewpoint of the boundary field theory. We focus on the specific example of the AdS5 × S 5 background with two probe D7 branes intersecting at general angles. For generic angles supersymmetry is completely broken and there is an open string tachyon between the branes. The field theory action for this system is obtained by coupling to {N}=4 super Yang-Mills two {N}=2 hyper multiplets in the fundamental representation of the SU( N) gauge group, but with different choices of embedding of the two {N}=2 subalgebras into {N}=4 . On the field theory side we find a one-loop Coleman-Weinberg instability in the effective potential for the fundamental scalars. We identify a mesonic operator as the dual of the open string tachyon. By AdS/CFT, we predict the tachyon mass for small 't Hooft coupling (large bulk curvature) and confirm that it violates the AdS stability bound.

  14. Branes are waves and monopoles

    Science.gov (United States)

    Berman, David S.; Rudolph, Felix J.

    2015-05-01

    In a recent paper it was shown that fundamental strings are null waves in Double Field Theory. Similarly, membranes are waves in exceptional extended geometry. Here the story is continued by showing how various branes are Kaluza-Klein monopoles of these higher dimensional theories. Examining the specific case of the E 7 exceptional extended geometry, we see that all branes are both waves and monopoles. Along the way we discuss the O( d, d) transformation of localized brane solutions not associated to an isometry and how true T-duality emerges in Double Field Theory when the background possesses isometries.

  15. AdS5 solutions from M5-branes on Riemann surface and D6-branes sources

    Science.gov (United States)

    Bah, Ibrahima

    2015-09-01

    We describe the gravity duals of four-dimensional N=1 superconformal field theories obtained by wrapping M5-branes on a punctured Riemann surface. The internal geometry, normal to the AdS 5 factor, generically preserves two U(1)s, with generators ( J +, J -), that are fibered over the Riemann surface. The metric is governed by a single potential that satisfies a version of the Monge-Ampère equation. The spectrum of N=1 punctures is given by the set of supersymmetric sources of the potential that are localized on the Riemann surface and lead to regular metrics near a puncture. We use this system to study a class of punctures where the geometry near the sources corresponds to M-theory description of D6-branes. These carry a natural ( p, q) label associated to the circle dual to the killing vector pJ + + qJ - which shrinks near the source. In the generic case the world volume of the D6-branes is AdS 5 × S 2 and they locally preserve N=2 supersymmetry. When p = - q, the shrinking circle is dual to a flavor U(1). The metric in this case is non-degenerate only when there are co-dimension one sources obtained by smearing M5-branes that wrap the AdS 5 factor and the circle dual the superconformal R-symmetry. The D6-branes are extended along the AdS 5 and on cups that end on the co-dimension one branes. In the special case when the shrinking circle is dual to the R-symmetry, the D6-branes are extended along the AdS 5 and wrap an auxiliary Riemann surface with an arbitrary genus. When the Riemann surface is compact with constant curvature, the system is governed by a Monge-Ampère equation.

  16. Brane Inflation, Solitons and Cosmological Solutions: I

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.

    2005-01-25

    In this paper we study various cosmological solutions for a D3/D7 system directly from M-theory with fluxes and M2-branes. In M-theory, these solutions exist only if we incorporate higher derivative corrections from the curvatures as well as G-fluxes. We take these corrections into account and study a number of toy cosmologies, including one with a novel background for the D3/D7 system whose supergravity solution can be completely determined. Our new background preserves all the good properties of the original model and opens up avenues to investigate cosmological effects from wrapped branes and brane-antibrane annihilation, to name a few. We also discuss in some detail semilocal defects with higher global symmetries, for example exceptional ones, that occur in a slightly different regime of our D3/D7 model. We show that the D3/D7 system does have the required ingredients to realize these configurations as non-topological solitons of the theory. These constructions also allow us to give a physical meaning to the existence of certain underlying homogeneous quaternionic Kahler manifolds.

  17. Measurable Stochastics for Brane Calculus

    Directory of Open Access Journals (Sweden)

    Giorgio Bacci

    2010-10-01

    Full Text Available We give a stochastic extension of the Brane Calculus, along the lines of recent work by Cardelli and Mardare. In this presentation, the semantics of a Brane process is a measure of the stochastic distribution of possible derivations. To this end, we first introduce a labelled transition system for Brane Calculus, proving its adequacy w.r.t. the usual reduction semantics. Then, brane systems are presented as Markov processes over the measurable space generated by terms up-to syntactic congruence, and where the measures are indexed by the actions of this new LTS. Finally, we provide a SOS presentation of this stochastic semantics, which is compositional and syntax-driven.

  18. Space-times of boosted p-branes, and CFT in infinite-momentum frame

    CERN Document Server

    Cvetic, M; Pope, C N

    1999-01-01

    We study the space-times of the near-horizon regions in D3-brane, M2-brane and M5-brane configurations, in cases where there is a pp-wave propagating along a direction in the world-volume. While non-extremal configurations of this kind locally have the same Carter-Novotny-Horsky-type metrics as those without the wave, taking the BPS limit results instead in Kaigorodov-type metrics, which are homogeneous, but preserve ((1)/(4)) of the supersymmetry, and have global and local structures that are quite different from the corresponding anti-de Sitter space-times associated with solutions where there is no pp-wave. We show that the momentum density of the system is non-vanishing and held fixed under the gravity decoupling limit. In view of the AdS/CFT correspondence, M-theory and type IIB theory in the near-horizon region of these boosted BPS-configurations specifies the corresponding CFT on the boundary in an infinitely boosted frame with constant momentum density. We model the microstates of such boosted configu...

  19. Coset construction of a D-brane gauge field

    Directory of Open Access Journals (Sweden)

    I.N. McArthur

    2016-04-01

    Full Text Available D-branes have a world-volume U(1 gauge field A whose field strength F=dA gives rise to a Born–Infeld term in the D-brane action. Supersymmetry and kappa symmetry transformations of A are traditionally inferred by the requirement that the Born–Infeld term is consistent with both supersymmetry and kappa symmetry of the D-brane action. In this paper, we show that integrability of the assigned supersymmetry transformations leads to an extension of the standard supersymmetry algebra that includes a fermionic central charge. We construct a superspace one-form on an enlarged superspace related by a coset construction to this centrally extended algebra whose supersymmetry and kappa symmetry transformations are derived, rather than inferred. It is shown that under pullback, these transformations are of the form expected for the D-brane U(1 gauge field. We relate these results to manifestly supersymmetric approaches to construction of D-brane actions.

  20. Viscous asymptotically flat Reissner-Nordström black branes

    Energy Technology Data Exchange (ETDEWEB)

    Gath, Jakob; Pedersen, Andreas Vigand [Niels Bohr Institute, University of Copenhagen,Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark)

    2014-03-12

    We study electrically charged asymptotically flat black brane solutions whose world-volume fields are slowly varying with the coordinates. Using familiar techniques, we compute the transport coefficients of the fluid dynamic derivative expansion to first order. We show how the shear and bulk viscosities are modified in the presence of electric charge and we compute the charge diffusion constant which is not present for the neutral black p-brane. We compute the first order dispersion relations of the effective fluid. For small values of the charge the speed of sound is found to be imaginary and the brane is thus Gregory-Laflamme unstable as expected. For sufficiently large values of the charge, the sound mode becomes stable, however, in this regime the hydrodynamic mode associated with charge diffusion is found to be unstable. The electrically charged brane is thus found to be (classically) unstable for all values of the charge density in agreement with general thermodynamic arguments. Finally, we show that the shear viscosity to entropy bound is saturated, as expected, while the proposed bounds for the bulk viscosity to entropy can be violated in certain regimes of the charge of the brane.

  1. Viscous asymptotically flat Reissner-Nordström black branes

    Science.gov (United States)

    Gath, Jakob; Pedersen, Andreas Vigand

    2014-03-01

    We study electrically charged asymptotically flat black brane solutions whose world-volume fields are slowly varying with the coordinates. Using familiar techniques, we compute the transport coefficients of the fluid dynamic derivative expansion to first order. We show how the shear and bulk viscosities are modified in the presence of electric charge and we compute the charge diffusion constant which is not present for the neutral black p-brane. We compute the first order dispersion relations of the effective fluid. For small values of the charge the speed of sound is found to be imaginary and the brane is thus Gregory-Laflamme unstable as expected. For sufficiently large values of the charge, the sound mode becomes stable, however, in this regime the hydrodynamic mode associated with charge diffusion is found to be unstable. The electrically charged brane is thus found to be (classically) unstable for all values of the charge density in agreement with general thermodynamic arguments. Finally, we show that the shear viscosity to entropy bound is saturated, as expected, while the proposed bounds for the bulk viscosity to entropy can be violated in certain regimes of the charge of the brane.

  2. New wormhole solutions on the brane

    Science.gov (United States)

    Parsaei, F.; Riazi, N.

    2015-01-01

    In this paper, static wormholes in the brane-world scenario are studied. We show that the existence of extra terms coming from the bulk help construct exact solutions that satisfy the null energy condition. Two important classes of solutions found earlier are analyzed in more depth in order to determine the conditions necessary for consistent solutions. Two new classes of solutions with different asymptotic behavior are also introduced. We focus on the conservation of the stress-energy tensor to achieve new solutions which have the important property of asymptotic flatness. Some main mathematical and physical properties of the solutions are addressed.

  3. Lectures on Warped Compactifications and Stringy Brane Constructions

    Energy Technology Data Exchange (ETDEWEB)

    Kachru, Shamit

    2001-07-26

    In these lectures, two different aspects of brane world scenarios in 5d gravity or string theory are discussed. In the first two lectures, work on how warped compactifications of 5d gravity theories can change the guise of the hierarchy problem and the cosmological constant problem is reviewed, and a discussion of several issues which remain unclear in this context is provided. In the next two lectures, microscopic constructions in string theory which involve D-branes wrapped on cycles of Calabi-Yau manifolds are described. The focus is on computing the superpotential in the brane worldvolume field theory. Such calculations may be a necessary step towards understanding e.g. supersymmetry breaking and moduli stabilization in stringy realizations of such scenarios, and are of intrinsic interest as probes of the quantum geometry of the Calabi-Yau space.

  4. Fluid/gravity correspondence and the CFM black brane solutions

    Energy Technology Data Exchange (ETDEWEB)

    Casadio, R. [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); I.N.F.N., Sezione di Bologna, Bologna (Italy); Cavalcanti, R.T. [Universita di Bologna, Dipartimento di Fisica e Astronomia, Bologna (Italy); Universidade Federal do ABC-UFABC, Centro de Ciencias Naturais e Humanas, Santo Andre (Brazil); Rocha, Roldao da [Universidade Federal do ABC-UFABC, Centro de Matematica, Computacao e Cognicao, Santo Andre (Brazil)

    2016-10-15

    We consider the lower bound for the shear viscosity-to-entropy density ratio, obtained from the fluid/gravity correspondence, in order to constrain the post-Newtonian parameter of brane-world metrics. In particular, we analyse the Casadio-Fabbri-Mazzacurati (CFM) effective solutions for the gravity side of the correspondence and argue that including higher-order terms in the hydrodynamic expansion can lead to a full agreement with the experimental bounds, for the Eddington-Robertson-Schiff post-Newtonian parameter in the CFM metrics. This lends further support to the physical relevance of the viscosity-to-entropy ratio lower bound and fluid/gravity correspondence. Hence we show that CFM black branes are, effectively, Schwarzschild black branes. (orig.)

  5. Fluid/gravity correspondence and the CFM black brane solutions

    Science.gov (United States)

    Casadio, R.; Cavalcanti, R. T.; da Rocha, Roldão

    2016-10-01

    We consider the lower bound for the shear viscosity-to-entropy density ratio, obtained from the fluid/gravity correspondence, in order to constrain the post-Newtonian parameter of brane-world metrics. In particular, we analyse the Casadio-Fabbri-Mazzacurati (CFM) effective solutions for the gravity side of the correspondence and argue that including higher-order terms in the hydrodynamic expansion can lead to a full agreement with the experimental bounds, for the Eddington-Robertson-Schiff post-Newtonian parameter in the CFM metrics. This lends further support to the physical relevance of the viscosity-to-entropy ratio lower bound and fluid/gravity correspondence. Hence we show that CFM black branes are, effectively, Schwarzschild black branes.

  6. Cosmic space and Pauli exclusion principle in a system of M0-branes

    Science.gov (United States)

    Capozziello, Salvatore; Saridakis, Emmanuel N.; Bamba, Kazuharu; Sepehri, Alireza; Rahaman, Farook; Ali, Ahmed Farag; Pincak, Richard; Pradhan, Anirudh

    An emergence of cosmic space has been suggested by Padmanabhan [Emergence and expansion of cosmic space as due to the quest for holographic equipartition, arXiv:hep-th/1206.4916] where he proposed that the expansion of the universe originates from a difference between the number of degrees of freedom on a holographic surface and the one in the emerged bulk. Now, a natural question that arises is how this proposal would explain the production of fermions and an emergence of the Pauli exclusion principle during the evolution of the universe? We try to address this issue in a system of M0-branes. In this model, there is a high symmetry and the system is composed of M0-branes to which only scalar fields are attached that represent scalar modes of the graviton. Then, when M0-branes join each other and hence form M1-branes, this symmetry is broken and gauge fields are formed. Therefore, these M1-branes interact with the anti-M1-branes and the force between them leads to a break of a symmetry such as the lower and upper parts of these branes are not the same. In these conditions, gauge fields which are localized on M1-branes and scalars which are attached to them symmetrically, decay to fermions with upper and lower spins which attach to the upper and lower parts of the M1-branes anti-symmetrically. The curvature produced by the coupling of identical spins has the opposite sign of the curvature produced by non-identical spins which lead to an attractive force between anti-parallel spins and a repelling force between parallel spins and hence an emergence of the Pauli exclusion principle. By approaching M1-branes to each other, the difference between curvatures of parallel spins and curvatures of anti-parallel spins increases, which leads to an inequality between the number of degrees of freedom on the surface and the one in the emerged bulk and hence lead to an occurrence of the cosmic expansion. By approaching M1-branes to each other, the square of the energy of the

  7. MODELING WORLD BIOENERGY CROP POTENTIAL

    Science.gov (United States)

    Hagiwara, Kensuke; Hanasaki, Naota; Kanae, Shinjiro

    Bioenergy is regarded as clean energy due to its characteristics and expected to be a new support of world energy de¬mand, but there are few integrated assessments of the potential of bioenergy considering sustainable land use. We esti¬mated the global bioenergy potential with an integrated global water resources model, the H08. It can simulate the crop yields on global-scale at a spatial resolution of 0.50.5. Seven major crops in the world were considered; namely, maize, sugar beet, sugar cane, soybean, rapeseed, rice, and wheat, of which the first 5 are commonly used to produce biofuel now. Three different land-cover types were chosen as potential area for cultivation of biofuel-producing crop: fallow land, grassland, and portion of forests (excluding areas sensitive for biodiversity such as frontier forest). We attempted to estimate the maximum global bioenergy potential and it was estimated to be 1120EJ. Bioenergy potential depends on land-use limitations for the protection of bio-diversity and security of food. In another condition which assumed more land-use limitations, bioenergy potential was estimated to be 70-233EJ.

  8. Gauge localization on a 3-brane with a transverse resolved conifold

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Francisco Wagner Vasconcelos da; Silva, Jose Euclides Gomes da; Almeida, Carlos Alberto Santos de [UFC, Fortaleza, CE (Brazil)

    2013-07-01

    Full text: The Kaluza-Klein theories, as well as other extra dimension theories, has been boosted after the seminal model of Randall and Sundrum (RS). In six dimensions, some models where the two dimensional manifold has a cylindrical symmetry according to the 3-brane are called string-like branes. A bad features of the string-like models is the conical behavior near the core of the string that prohibits a zero-mode on the brane for both gauge and spinor fields and yields tachyonic massive gravitational modes on the brane. In this work, we investigate the properties of the gauge vector field in a braneworld scenario built as a warped product between a 3-brane and a 2-cycle of the resolved conifold. This scenario allowed to study how the gauge field behaves when the transverse manifold evolves upon a geometric flow that controls the singularity at the origin. Since the transverse manifold has a cylindrical symmetry according to the 3-brane, this geometry can be regarded as a near brane correction of the string-like branes. By means of a new warp function and the parameter-dependent angular metric component of the resolved conifold, the braneworld can exhibit a conical form near the origin as well as a regular behavior in that region. The analysis of the gauge field in this background has been carried out for the s-wave state and a normalizable massless mode was found. For the massive modes, the resolution parameter avoids an infinite well on the brane and controls the depth of the well and the high of the barrier around the brane. The massive modes are slightly changed near the brane but they agreed with the string-like spectrum for large distances. (author)

  9. Localization and mass spectra of various matter fields on Weyl thin brane

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Tao-Tao; Zhao, Li; Zhang, Yu-Peng [Lanzhou University, Institute of Theoretical Physics, Lanzhou (China); Xie, Qun-Ying [Lanzhou University, School of Information Science and Engineering, Lanzhou (China)

    2017-06-15

    It has been shown that the thin brane model in a five-dimensional Weyl gravity can deal with the wrong-signed Friedmann-like equation in the Randall-Sundrum-1 (RS1) model. In the Weyl brane model, there are also two branes with opposite brane tensions, but the four-dimensional graviton (the gravity zero mode) is localized near the negative tension brane, while our four-dimensional universe is localized on the positive tension brane. In this paper, we consider the mass spectra of various bulk matter fields (i.e., scalar, vector, and fermion fields) on the Weyl brane. It is shown that the zero modes of those matter fields can be localized on the positive tension brane under some conditions. The mass spectra of the bulk matter fields are equidistant for the higher excited states, and relatively sparse for the lower excited states. The size of the extra dimension determines the gap of the mass spectra. We also consider the correction to the Newtonian potential in this model and it is proportional to 1/r{sup 3}. (orig.)

  10. Towards realistic string vacua from branes at singularities

    CERN Document Server

    Conlon, Joseph P; Quevedo, Fernando

    2009-01-01

    We report on progress towards constructing string models incorporating both realistic D-brane matter content and full moduli stabilisation with dynamical low-scale supersymmetry breaking. The general framework is that of local D-brane models embedded into the LARGE volume approach to moduli stabilisation. We review quiver theories on del Pezzo n (dP_n) singularities including both D3 and D7 branes. We provide supersymmetric examples with three quark/lepton families and the gauge symmetries of the Standard, Left-Right Symmetric, Pati-Salam and Trinification models, without unwanted chiral exotics. We describe how the singularity structure leads to family symmetries governing the Yukawa couplings which can give mass hierarchies among the different generations. We outline how these models can be embedded into compact Calabi-Yau compactifications with LARGE volume moduli stabilisation, and state the minimal conditions for this to be possible. We study the general structure of soft supersymmetry breaking. At the s...

  11. D-brane physics. From weak to strong coupling

    Energy Technology Data Exchange (ETDEWEB)

    Vieira Lopes, Daniel Ordine

    2013-01-10

    In this thesis we discuss two aspects of branes relevant to high-energy phenomenology. First, we consider a single D6-brane wrapping a special Lagrangian cycle and the background space compactified in a Calabi-Yau orientifold the conditions needed to obtain a four-dimensional N=1 supersymmetric theory. We calculate the bosonic part of the effective action by performing a Kaluza-Klein reduction of the brane seven-dimensional action, and obtain the N=1 characteristic data. To discuss the moduli, we first fix the moduli from deformations of the background Calabi-Yau and study the D-brane deformation moduli space. We next allow for Calabi-Yau deformations, and show that the moduli space for complex structure deformations is corrected by the fields living on the D6-brane. We also calculate the scalar potential from D- and F-terms generated from brane and background configurations that would break the supersymmetry condition. We then, via Mirror Symmetry, relate the spectrum obtained in our work to the spectrum in Type IIB effective theory with D3- D5- and D7-branes, and we propose a Kaehler potential for the moduli space of brane deformations in Type IIB theories. In the second part of the thesis we discuss effects of brane intersections when the string coupling can become strong, and we work in the framework of F-theory. After reviewing the basics of F-theory constructions and a particular SU(5) model already discussed in the literature, we construct a model which contains a point of E{sub 8} singularity, and curves of E{sub 6} singularity. By explicitly resolving the space, we show that the resolution requires the introduction of higher dimensional fibers, and argue how we can circumvent this problem for the E{sub 6} curve, leading to the expected resolution that generate an E{sub 6} group, while at the E{sub 8} point we cannot make the resolution lead to an expected E{sub 8} structure.

  12. -branes in ФФ-wave background

    Indian Academy of Sciences (India)

    stability of a system of D3-branes oriented at certain angle (a), by writing down an ansatz and solving the corresponding type-IIB field equations in pp-wave back- ground. This brane configuration is shown to preserve 1/16 supersymmetries. We start by writing down the supergravity solution of D5-brane in pp-wave.

  13. Type II p-branes the brane-scan revisited

    CERN Document Server

    Duff, Michael J

    1993-01-01

    We re-examine the classification of supersymmetric extended objects in the light of the recently discovered Type II p-branes, previously thought not to exist for p> 1. We find new points on the brane-scan only in D = 10 and then only for p = 3(Type IIB), p = 4 (Type IIA), p = 5 (Type IIA and IIB) and p = 6 (Type IIA). The case D = 10, p = 2 (Type IIA) also exists but is equivalent to the previously classified D = 11 supermembrane.

  14. Non-geometric fluxes & tadpole conditions for exotic branes

    Science.gov (United States)

    Lombardo, Davide M.; Riccioni, Fabio; Risoli, Stefano

    2017-10-01

    We extend the P -flux analysis carried out recently on the T 6/[ℤ2 × ℤ2] type-II orientifold model to include all the possible non-geometric fluxes. By deriving universal T-duality rules for all the fluxes, we are able to write down a complete expression for the superpotential for both the IIB and IIA theories. By exploiting the universal T-duality rules that apply to all the branes in string theory, we then identify all the exotic branes that can be consistently included to cancel the tadpoles induced by the fluxes. Finally, we derive the representations of these branes with respect to the SL(2, ℤ)7 duality symmetry of the model.

  15. Nernst branes with Lifshitz asymptotics in N=2 gauged supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, G.L. [Center for Mathematical Analysis, Geometry and Dynamical Systems,Instituto Superior Técnico, Universidade de Lisboa,Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Haack, M. [Arnold Sommerfeld Center for Theoretical Physics,Ludwig-Maximilians-Universität München,Theresienstrasse 37, 80333 München (Germany); Nampuri, S. [Center for Mathematical Analysis, Geometry and Dynamical Systems,Instituto Superior Técnico, Universidade de Lisboa,Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2016-06-23

    We discuss two classes of non-supersymmetric interpolating solutions in N=2, D=4 gauged supergravity, that flow from either a z=2 Lifshitz geometry or a conformal AdS background to the near-horizon geometry of a Nernst brane. We obtain these solutions by constructing a z=2 supersymmetric Lifshitz solution in the STU model from a first-order rewriting of the action, then lifting it up to a five-dimensional background and subsequently modifying this five-dimensional solution by a two-parameter family of deformations. Under reduction, these give four-dimensional non-supersymmetric Nernst brane solutions. This is a step towards resolving the Lifshitz tidal force singularity in the context of N=2 gauged supergravity and suggests an approach to encoding the Nernst brane in terms of the Schrödinger symmetry group of the holographically dual field theory.

  16. Lifshitz hydrodynamics from Lifshitz black branes with linear momentum

    Energy Technology Data Exchange (ETDEWEB)

    Hartong, Jelle [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Obers, Niels A.; Sanchioni, Marco [The Niels Bohr Institute, Copenhagen University,Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark)

    2016-10-21

    We construct a new class of 4-dimensional z=2 Lifshitz black branes that have a non-zero linear momentum. These are solutions of an Einstein-Proca-dilaton model that can be obtained by Scherk-Schwarz circle reduction of AdS{sub 5} gravity coupled to a free real scalar field. The boundary of a bulk Lifshitz space-time is a Newton-Cartan geometry. We show that the fluid dual to the moving Lifshitz black brane leads to a novel form of Lifshitz hydrodynamics on a Newton-Cartan space-time. Since the linear momentum of the black brane cannot be obtained by a boost transformation the velocity of the fluid or rather, by boundary rotational invariance, its magnitude plays the role of a chemical potential. The conjugate dual variable is mass density. The Lifshitz perfect fluid can be thought of as arising from a Schrödinger perfect fluid with broken particle number symmetry.

  17. T-branes at the limits of geometry

    Science.gov (United States)

    Anderson, Lara B.; Heckman, Jonathan J.; Katz, Sheldon; Schaposnik, Laura P.

    2017-10-01

    Singular limits of 6D F-theory compactifications are often captured by T-branes, namely a non-abelian configuration of intersecting 7-branes with a nilpotent matrix of normal deformations. The long distance approximation of such 7-branes is a Hitchin-like system in which simple and irregular poles emerge at marked points of the geometry. When multiple matter fields localize at the same point in the geometry, the associated Higgs field can exhibit irregular behavior, namely poles of order greater than one. This provides a geometric mechanism to engineer wild Higgs bundles. Physical constraints such as anomaly cancellation and consistent coupling to gravity also limit the order of such poles. Using this geometric formulation, we unify seemingly different wild Hitchin systems in a single framework in which orders of poles become adjustable parameters dictated by tuning gauge singlet moduli of the F-theory model.

  18. On the structure of composite black p-brane configurations and related black holes

    CERN Document Server

    Tseytlin, Arkady A

    1997-01-01

    We comment on the structure of intersecting black p-brane solutions in string theory. In particular, we explain why dimensional reduction in all internal world-volume directions including time leads to a metric (related by analytic continuation to a cosmological metric) which does not depend on p-brane charges, i.e. is the same as the metric following by reduction from a higher-dimensional `neutral' Schwarzschild black hole.

  19. Non-perturbative effects on seven-brane Yukawa couplings

    CERN Document Server

    Marchesano, Fernando

    2010-01-01

    We analyze non-perturbative corrections to the superpotential of seven-brane gauge theories on type IIB and F-theory warped Calabi-Yau compactifications. We show in particular that such corrections modify the holomorphic Yukawa couplings by an exponentially suppressed contribution, generically solving the Yukawa rank-one problem present in F-theory local models. We provide explicit expressions for the non-perturbative correction to the seven-brane superpotential, and check that it is related to a non-commutative deformation to the tree-level superpotential via the Seiberg-Witten map.

  20. Type IIA string theory on T{sup 6}/(Z{sub 2} x Z{sub 6} x ΩR). Model building and string phenomenology with intersecting D6-branes

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, Jill

    2016-07-27

    In this doctoral thesis, various aspects of string model building and phenomenology are investigated within the framework of Type IIA string theory on the T{sup 6}/(Z{sub 2} x Z{sub 6} x ΩR) orbifold with discrete torsion. The aim is the reproduction of supersymmetric versions of well-known particle physics models using intersecting rigid D6-branes wrapped on fractional three-cycles. The models analyzed include the minimal supersymmetric Standard Model as well as supersymmetric Pati-Salam models, left-right symmetric models and SU(5) models. Systematic computer scans test numerous combinations of intersecting D6-branes in order to detect those that give rise to the correct chiral particle content of the considered models. For each type of the afore mentioned models, concrete examples will be found which satisfy the constraints on the particle spectrum and fulfill all consistency conditions. Finally, the thesis focuses on phenomenological aspects of the particle physics models found, including the detection of massless U(1) combinations, discrete Z{sub n}-symmetries and cubic couplings such as the Yukawa couplings.

  1. 750 GeV diphotons from a D3-brane

    Directory of Open Access Journals (Sweden)

    Jonathan J. Heckman

    2016-05-01

    Full Text Available Motivated by the recently reported diphoton excess at 750 GeV observed by both CMS and ATLAS, we study string-based particle physics models which can accommodate this signal. Quite remarkably, although Grand Unified Theories in F-theory tend to impose tight restrictions on candidate extra sectors, the case of a probe D3-brane near an E-type Yukawa point naturally leads to a class of strongly coupled models capable of accommodating the observed signature. In these models, the visible sector is realized by intersecting 7-branes, and the 750 GeV resonance is a scalar modulus associated with motion of the D3-brane in the direction transverse to the Standard Model 7-branes. Integrating out heavy 3–7 string messenger states leads to dimension five operators for gluon fusion production and diphoton decays. Due to the unified structure of interactions, these models also predict that there should be additional decay channels to ZZ and Zγ. We also comment on models with distorted unification, where both the production mechanism and decay channels can differ.

  2. Branes, weights and central charges

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Riccioni, Fabio; Romano, Luca

    We study the properties of half-supersymmetric branes in string theory with 32 supercharges from a purely group-theoretical point of view using the U-duality symmetry of maximal supergravity and the R-symmetry of the corresponding supersymmetry algebra. In particular, we show that

  3. World Magnetic Model 2015 Technical Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Magnetic Model is the standard model used by the U.S. Department of Defense, the U.K. Ministry of Defence, the North Atlantic Treaty Organization (NATO)...

  4. Tree Level Potential on Brane after Planck and BICEP2

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In this regard, we propose a study of the tree level potential inflation in the framework of the Randall–Sundrum type-2 braneworld model. We focus on three branches of the potential, where we evaluate some values of brane tension . We discuss how the various inflationary perturbation parameters can be ...

  5. Cosmology from quantum potential in brane-anti-brane system

    Science.gov (United States)

    Sepehri, Alireza

    2015-09-01

    Recently, some authors removed the big-bang singularity and predicted an infinite age of our universe. In this paper, we show that the same result can be obtained in string theory and M-theory; however, the shape of universe changes in different epochs. In our mechanism, first, N fundamental string decay to N D0-anti-D0-brane. Then, D0-branes join each other, grow and form a six-dimensional brane-antibrane system. This system is unstable, broken and at present the form of four-dimensional universes, one anti-universe in addition to one wormhole are produced. Thus, there isn't any big-bang in cosmology and the universe is a fundamental string at the beginning. Also, the total age of universe contains two parts, one is related to initial age and the other corresponds to the present age of universe (ttot =tinitial +tpresent). On the other hand, the initial age of universe includes two parts, the age of fundamental string and the time of transition (tinitial =ttransition +tf-string). We observe that only in the case of (tf-string → ∞), the scale factor of universe is zero and as a result, the total age of universe is infinity.

  6. Cosmology from quantum potential in brane-anti-brane system

    CERN Document Server

    Sepehri, Alireza

    2015-01-01

    Recently, some authors removed the big-bang singularity and predicted an infinite age of our universe. In this paper, we show that the same result can be obtained in string theory and M-theory; however, the shape of universe changes in different epochs. In our mechanism, first, N fundamental string decay to N D0-anti-D0-brane. Then, D0-branes join to each other, grow and and form a six-dimensional brane-antibrane system. This system is unstable, broken and present form of four dimensional universes , one anti-universe in additional to one wormhole are produced. Thus, there isn't any big-bang in cosmology and universe is a fundamental string at the beginning. Also, total age of universe contains two parts, one in related to initial age and second which is corresponded to present age of universe ($t_{tot}=t_{initial}+t_{present}$). On the other hand, initial age of universe includes two parts, the age of fundamental string and time of transition ($t_{initial}=t_{transition}+t_{f-string}$). We observe that only ...

  7. Coupling brane fields to bulk supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Parameswaran, Susha L. [Uppsala Univ. (Sweden). Theoretical Physics; Schmidt, Jonas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    In this note we present a simple, general prescription for coupling brane localized fields to bulk supergravity. We illustrate the procedure by considering 6D N=2 bulk supergravity on a 2D orbifold, with brane fields localized at the fixed points. The resulting action enjoys the full 6D N=2 symmetries in the bulk, and those of 4D N=1 supergravity at the brane positions. (orig.)

  8. The evolution of Brown-York quasilocal energy as due to evolution of Lovelock gravity in a system of M0-branes

    Science.gov (United States)

    Sepehri, Alireza; Rahaman, Farook; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh

    Recently, it has been suggested in [S. Chakraborty and N. Dadhich, Brown-York quasilocal energy in Lanczos-Lovelock gravity and black hole horizons, J. High Energ. Phys. 12 (2015) 003.] that the Brown-York mechanism can be used to measure the quasilocal energy in Lovelock gravity. We have used this method in a system of M0-branes and show that the Brown-York energy evolves in the process of birth and growth of Lovelock gravity. This can help us to predict phenomenological events which are emerged as due to dynamical structure of Lovelock gravity in our universe. In this model, first, M0-branes join each other and form an M3-brane and an anti-M3-branes connected by an M2-brane. This system is named BIon. Universes and anti-universes live on M3-branes and M2 plays the role of wormhole between them. By passing time, M2 dissolves in M3’s and nonlinear massive gravities like Lovelock massive gravity emerges and grows. By closing M3-branes, BIon evolves and wormhole between branes makes a transition to black hole. During this stage, Brown-York energy increases and shrinks to large values at the colliding points of branes. By approaching M3-branes towards each other, the square energy of their system becomes negative and some tachyonic states are produced. To remove these states, M3-branes compact, the sign of compacted gravity changes, anti-gravity is created which leads to getting away of branes from each other. Also, the Lovelock gravity disappears and its energy forms a new M2 between M3-branes. By getting away of branes from each other, Brown-York energy decreases and shrinks to zero.

  9. D-Branes on ALE Spaces and the ADE Classification of Conformal Field Theories

    CERN Document Server

    Lerche, Wolfgang; Schweigert, C

    2002-01-01

    The spectrum of D2-branes wrapped on an ALE space of general ADE type is determined, by representing them as boundary states of N=2 superconformal minimal models. The stable quantum states have RR charges which precisely represent the gauge fields of the corresponding Lie algebra. This provides a simple and direct physical link between the ADE classification of N=2 superconformal field theories, and the corresponding root systems. An affine extension of this structure is also considered, whose boundary states represent the D2-branes plus additional D0-branes.

  10. A local-world evolving hypernetwork model

    Science.gov (United States)

    Yang, Guang-Yong; Liu, Jian-Guo

    2014-01-01

    Complex hypernetworks are ubiquitous in the real system. It is very important to investigate the evolution mechanisms. In this paper, we present a local-world evolving hypernetwork model by taking into account the hyperedge growth and local-world hyperedge preferential attachment mechanisms. At each time step, a newly added hyperedge encircles a new coming node and a number of nodes from a randomly selected local world. The number of the selected nodes from the local world obeys the uniform distribution and its mean value is m. The analytical and simulation results show that the hyperdegree approximately obeys the power-law form and the exponent of hyperdegree distribution is γ = 2 + 1/m. Furthermore, we numerically investigate the node degree, hyperedge degree, clustering coefficient, as well as the average distance, and find that the hypernetwork model shares the scale-free and small-world properties, which shed some light for deeply understanding the evolution mechanism of the real systems.

  11. Teleparallel loop quantum cosmology in a system of intersecting branes

    Science.gov (United States)

    Sepehri, Alireza; Pradhan, Anirudh; Beesham, Aroonkumar; de Haro, Jaume

    2016-09-01

    Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC) and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps around the D4 brane from one end and sticks to one of the anti-D8 branes from the other one. In this system, there are three types of fields, corresponding to compacted D4 branes, intersecting branes and D3-branes. These fields interact with each other and make the angle between branes oscillate. By decreasing this angle, the intersecting anti-D8 branes approach each other, the D4 brane rolls, the D3 brane wraps around the D4 brane, and the universe contracts. By separating the intersecting branes and increasing the angle, the D4 brane rolls in the opposite direction, the D3 brane separates from it and the expansion branch begins. Also, the interaction between branes in this system gives us the exact form of the relevant Lagrangian for teleparallel LQC.

  12. Teleparallel loop quantum cosmology in a system of intersecting branes

    Energy Technology Data Exchange (ETDEWEB)

    Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Pradhan, Anirudh, E-mail: pradhan.anirudh@gmail.com [Department of Mathematics, Institute of Applied Sciences and Humanities, GLA University, Mathura-281 406, Uttar Pradesh (India); Beesham, Aroonkumar, E-mail: beeshama@unizulu.ac.za [Department of Mathematical Sciences, University of Zululand, Kwa-Dlangezwa 3886 (South Africa); Haro, Jaume de, E-mail: jaime.haro@upc.edu [Departament de Matemàtiques, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain)

    2016-09-10

    Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC) and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps around the D4 brane from one end and sticks to one of the anti-D8 branes from the other one. In this system, there are three types of fields, corresponding to compacted D4 branes, intersecting branes and D3-branes. These fields interact with each other and make the angle between branes oscillate. By decreasing this angle, the intersecting anti-D8 branes approach each other, the D4 brane rolls, the D3 brane wraps around the D4 brane, and the universe contracts. By separating the intersecting branes and increasing the angle, the D4 brane rolls in the opposite direction, the D3 brane separates from it and the expansion branch begins. Also, the interaction between branes in this system gives us the exact form of the relevant Lagrangian for teleparallel LQC.

  13. Teleparallel loop quantum cosmology in a system of intersecting branes

    Directory of Open Access Journals (Sweden)

    Alireza Sepehri

    2016-09-01

    Full Text Available Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps around the D4 brane from one end and sticks to one of the anti-D8 branes from the other one. In this system, there are three types of fields, corresponding to compacted D4 branes, intersecting branes and D3-branes. These fields interact with each other and make the angle between branes oscillate. By decreasing this angle, the intersecting anti-D8 branes approach each other, the D4 brane rolls, the D3 brane wraps around the D4 brane, and the universe contracts. By separating the intersecting branes and increasing the angle, the D4 brane rolls in the opposite direction, the D3 brane separates from it and the expansion branch begins. Also, the interaction between branes in this system gives us the exact form of the relevant Lagrangian for teleparallel LQC.

  14. Black branes in flux compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Torroba, Gonzalo; Wang, Huajia

    2013-10-01

    We construct charged black branes in type IIA flux compactifications that are dual to (2 + 1)-dimensional field theories at finite density. The internal space is a general Calabi-Yau manifold with fluxes, with internal dimensions much smaller than the AdS radius. Gauge fields descend from the 3-form RR potential evaluated on harmonic forms of the Calabi-Yau, and Kaluza-Klein modes decouple. Black branes are described by a four-dimensional effective field theory that includes only a few light fields and is valid over a parametrically large range of scales. This effective theory determines the low energy dynamics, stability and thermodynamic properties. Tools from flux compactifications are also used to construct holographic CFTs with no relevant scalar operators, that can lead to symmetric phases of condensed matter systems stable to very low temperatures. The general formalism is illustrated with simple examples such as toroidal compactifications and manifolds with a single size modulus. We initiate the classification of holographic phases of matter described by flux compactifications, which include generalized Reissner-Nordstrom branes, nonsupersymmetric AdS2×R2 and hyperscaling violating solutions.

  15. Defect branes as Alice strings

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Takashi [Theoretical Biology Laboratory, RIKEN,Wako 351-0198 (Japan); Sakatani, Yuho [Department of Physics and Astronomy,Seoul National University, Seoul 151-747 (Korea, Republic of)

    2015-03-25

    There exist various defect-brane backgrounds in supergravity theories which arise as the low energy limit of string theories. These backgrounds typically have non-trivial monodromies, and if we move a charged probe around the center of a defect, its charge will be changed by the action of the monodromy. During the process, the charge conservation law seems to be violated. In this paper, to resolve this puzzle, we examine a dynamics of the charge changing process and show that the missing charge of the probe is transferred to the background. We then explicitly construct the resultant background after the charge transfer process by utilizing dualities. This background has the same monodromy as the original defect brane, but has an additional charge which does not have any localized source. In the literature, such a charge without localized source is known to appear in the presence of Alice strings. We argue that defect branes can in fact be regarded as a realization of Alice strings in string theory and examine the charge transfer process from that perspective.

  16. D-brane disformal coupling and thermal dark matter

    Science.gov (United States)

    Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

    2017-11-01

    Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.

  17. Dirichlet branes and nonperturbative aspects of supersymmetric string and gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Zheng [Univ. of California, Berkeley, CA (United States)

    1998-05-01

    In chapter 1 the author reviews some elements of string theory relevant to the rest of this report. He touches on both the classical, i.e. perturbative, string physics before D-branes rise to prominence, and some of the progresses they brought forth. In chapter 2 he proceeds to give an exact algebraic formulation of D-branes in curved spaces. This allows one to classify them in backgrounds of interest and study their geometric properties. He applies this formalism to string theory on Calabi-Yau and other supersymmetry preserving manifolds. Then he studies the behavior of the D-branes under mirror symmetry in chapter 3. Mirror symmetry is known to be a symmetry of string theory perturbatively. He finds evidence for its nonperturbative validity when D-branes are also considered and compute some dynamical consequences. In chapter 4 he turns to examine the consistency of curved and/or intersecting D-brane configurations. They have been used recently to extract information about the field theories that arise in certain limits. It turns out that there are potential quantum mechanical inconsistencies associated with them. What saves the day are certain subtle topological properties of D-branes. This resolution has implications for the conserved charges carried by the D-branes, which he computes for the cases studied in chapter 2. In chapter 5 he uses intersecting brane configurations to study three dimensional supersymmetric gauge theories. There is also a mirror symmetry there that, among other things, exchanges classical and quantum mechanical quantities of a (mirror) pair of theories. It has an elegant realization in term of a symmetry of string theory involving D-branes. The author employs it to study a wide class of 3d models. He also predicts new mirror pairs and unconventional 3d field theories without Lagrangian descriptions.

  18. Dynamical Formation of Horizons in Recoiling D Branes

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, Dimitri V; Ellis, John

    2000-01-01

    A toy calculation of string/D-particle interactions within a world-sheet approach indicates that quantum recoil effects - reflecting the gravitational back-reaction on space-time foam due to the propagation of energetic particles - induces the appearance of a microscopic event horizon, or `bubble', inside which stable matter can exist. The scattering event causes this horizon to expand, but we expect quantum effects to cause it to contract again, in a `bounce' solution. Within such `bubbles', massless matter propagates with an effective velocity that is less than the velocity of light in vacuo, which may lead to observable violations of Lorentz symmetry that may be tested experimentally. The conformal invariance conditions in the interior geometry of the bubbles select preferentially three for the number of the spatial dimensions, corresponding to a consistent formulation of the interaction of D3 branes with recoiling D particles, which are allowed to fluctuate independently only on the D3-brane hypersurface.

  19. Aspects Of D-branes : From Branes In Motion To Meson Spectroscopy

    CERN Document Server

    Winters, D J

    2004-01-01

    We discuss various aspects of D-branes, ranging from their basic properties as extended objects within string theory to their application, via the AdS/CFT correspondence, to the physics of gauge theories. Our initial emphasis is on the description of time-dependent, yet supersymmetric, brane configurations and to this end we first provide a review of established results on D- branes. We then investigate various supersymmetric brane intersections. Motivated by the recent results on supertubes, we investigate general constraints under which parallel brane-antibrane configurations are supersymmetric. Dual descriptions of these configurations involve systems of intersecting branes in relative motion. In particular, we find new supersymmetric configurations which are not related to a static brane intersection by a boost. In these new configurations, the intersection point moves at the speed of light. We then briefly review the AdS/CFT correspondence between string and gauge theories. Our emphasis here is on the re...

  20. Origin of the Drude peak and of zero sound in probe brane holography

    Science.gov (United States)

    Chen, Chi-Fang; Lucas, Andrew

    2017-11-01

    At zero temperature, the charge current operator appears to be conserved, within linear response, in certain holographic probe brane models of strange metals. At small but finite temperature, we analytically show that the weak non-conservation of this current leads to both a collective ;zero sound; mode and a Drude peak in the electrical conductivity. This simultaneously resolves two outstanding puzzles about probe brane theories. The nonlinear dynamics of the current operator itself appears qualitatively different.

  1. D-branes as solitons of an

    Energy Technology Data Exchange (ETDEWEB)

    Mihailescu, M.; Park, I. Y.; Tran, T. A.

    2001-08-15

    We consider a Dp-brane within a D9-brane in the presence of a B field whose polarization is transverse to the Dp-brane. To be definite, we take a D3-D9 system. It is observed that the system has the same pattern of supersymmetry breaking as that of a soliton of the six-dimensional noncommutative gauge theory that is obtained by dimensional reduction of an N=1,D=10 gauge theory. These results indicate that the soliton solution is the low energy realization of a D3-brane in a D9-brane with a transverse B field and, hence, can be viewed as a generalization of the previous results in the literature where similar observations were made for lower codimensional cases.

  2. Dimensional reduction for D3-brane moduli

    Energy Technology Data Exchange (ETDEWEB)

    Cownden, Brad [Department of Physics & Astronomy, University of Manitoba,Winnipeg, Manitoba R3T 2N2 (Canada); Frey, Andrew R. [Department of Physics & Astronomy, University of Manitoba,Winnipeg, Manitoba R3T 2N2 (Canada); Department of Physics, University of Winnipeg,Winnipeg, Manitoba R3B 2E9 (Canada); Marsh, M.C. David [Department of Applied Mathematics and Theoretical Physics, University of Cambridge,Cambridge, CB3 0WA (United Kingdom); Underwood, Bret [Department of Physics, Pacific Lutheran University,Tacoma, WA 98447 (United States)

    2016-12-28

    Warped string compactifications are central to many attempts to stabilize moduli and connect string theory with cosmology and particle phenomenology. We present a first-principles derivation of the low-energy 4D effective theory from dimensional reduction of a D3-brane in a warped Calabi-Yau compactification of type IIB string theory with imaginary self-dual 3-form flux, including effects of D3-brane motion beyond the probe approximation, and find the metric on the moduli space of brane positions, the universal volume modulus, and axions descending from the 4-form potential. As D3-branes may be considered as carrying either electric or magnetic charges for the self-dual 5-form field strength, we present calculations in both duality frames. Our results are consistent with, but extend significantly, earlier results on the low-energy effective theory arising from D3-branes in string compactifications.

  3. Defect (p,q five-branes

    Directory of Open Access Journals (Sweden)

    Tetsuji Kimura

    2015-04-01

    Full Text Available We study a local description of composite five-branes of codimension two. The formulation is constructed by virtue of SL(2,Z×SL(2,Z monodromy associated with two-torus. Applying conjugate monodromy transformations to the complex structures of the two-torus, we obtain a field configuration of a defect (p,q five-brane. This is a composite state of p defect NS5-branes and q exotic 522-branes. We also obtain a new example of hyper-Kähler geometry. This is an ALG space, a generalization of an ALF space which asymptotically has a tri-holomorphic two-torus action. This geometry appears in the conjugate configuration of a single defect KK5-brane.

  4. Hydrodynamics and Elasticity of Charged Black Branes

    DEFF Research Database (Denmark)

    Gath, Jakob

    We consider long-wavelength perturbations of charged black branes to first order in a uidelastic derivative expansion. At first order the perturbations decouple and we treat the hydrodynamic and elastic perturbations separately. To put the results in a broader perspective, we present the rst......-order corrected dynamics of uid branes carrying higher-form charge by obtaining the general form of their equations of motion to pole-dipole order in the absence of external forces. To monopole order, we characterize the corresponding effective theory of viscous uid branes by writing down the general form......)isotropic uid branes in terms of two sets of response coecients, the Young modulus and the piezoelectric moduli. We subsequently consider a large class of examples in gravity of this effective theory. In particular, we consider dilatonic black p-branes in two different settings: charged under a Maxwell gauge...

  5. A holographic bound for D3-brane

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)

    2017-06-15

    In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)

  6. The goldstino brane, the constrained superfields and matter in N=1 supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Bandos, Igor [Department of Theoretical Physics, University of the Basque Country UPV/EHU,P.O. Box 644, 48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science,48011, Bilbao (Spain); Heller, Markus [Dipartimento di Fisica e Astronomia “Galileo Galilei' , Università degli Studi di Padova,Via Marzolo 8, 35131 Padova (Italy); Institut für Theoretische Physik, Ruprecht-Karls-Universität,Philosophenweg 19, 69120 Heidelberg (Germany); Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia35 Stirling Highway, Crawley W.A. 6009 (Australia); Martucci, Luca [Dipartimento di Fisica e Astronomia “Galileo Galilei' , Università degli Studi di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN - Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Sorokin, Dmitri [INFN - Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Dipartimento di Fisica e Astronomia “Galileo Galilei' , Università degli Studi di Padova,Via Marzolo 8, 35131 Padova (Italy)

    2016-11-21

    We show that different (brane and constrained superfield) descriptions for the Volkov-Akulov goldstino coupled to N=1, D=4 supergravity with matter produce similar wide classes of models with spontaneously broken local supersymmetry and discuss the relation between the different formulations. As with the formulations with irreducible constrained superfields, the geometric goldstino brane approach has the advantage of being manifestly off-shell supersymmetric without the need to introduce auxiliary fields. It provides an explicit solution of the nilpotent superfield constraints and avoids issues with non-Gaussian integration of auxiliary fields. We describe general couplings of the supersymmetry breaking sector, including the goldstino and other non-supersymmetric matter, to supergravity and matter supermultiplets. Among various examples, we discuss a goldstino brane contribution to the gravitino mass term and the supersymmetrization of the anti-D3-brane contribution to the effective theory of type IIB warped flux compactifications.

  7. D-brane Inspired Fermion Mass Textures

    CERN Document Server

    Leontaris, G K

    2010-01-01

    In this paper, the issues of the quark mass hierarchies and the Cabbibo Kobayashi Maskawa mixing are analyzed in a class of intersecting D-brane configurations with Standard Model gauge symmetry. The relevant mass matrices are constructed taking into account the constraints imposed by extra abelian symmetries and anomaly cancelation conditions. Possible mass generating mechanisms including perturbative as well as non-perturbative effects are discussed and specific patterns of mass textures are found characterized by the hierarchies of the scales where the various sources contribute. It is argued that the Cholesky decomposition of the mass matrices is the most appropriate way to determine the properties of these fermion mass patterns, while the associated triangular mass matrix form provides a unified description of all phenomenologically equivalent symmetric and non-symmetric mass matrices. An elegant analytic formula is derived for the Cholesky triangular form of the mass matrices where the entries are given...

  8. Split supersymmetry in brane models

    Indian Academy of Sciences (India)

    guns for the presence of new physics at high energies. Supersymmetry is then a nice candidate offering both properties. Moreover, it arises naturally in ... Obviously, the field theory expression (1) is reproduced in the weak field limit. The Gauss law for the magnetic flux implies that the field H is quantized in terms of the area ...

  9. Towards realistic string vacua from branes at singularities

    Science.gov (United States)

    Conlon, Joseph P.; Maharana, Anshuman; Quevedo, Fernando

    2009-05-01

    We report on progress towards constructing string models incorporating both realistic D-brane matter content and moduli stabilisation with dynamical low-scale supersymmetry breaking. The general framework is that of local D-brane models embedded into the LARGE volume approach to moduli stabilisation. We review quiver theories on del Pezzo n (dPn) singularities including both D3 and D7 branes. We provide supersymmetric examples with three quark/lepton families and the gauge symmetries of the Standard, Left-Right Symmetric, Pati-Salam and Trinification models, without unwanted chiral exotics. We describe how the singularity structure leads to family symmetries governing the Yukawa couplings which may give mass hierarchies among the different generations. We outline how these models can be embedded into compact Calabi-Yau compactifications with LARGE volume moduli stabilisation, and state the minimal conditions for this to be possible. We study the general structure of soft supersymmetry breaking. At the singularity all leading order contributions to the soft terms (both gravity- and anomaly-mediation) vanish. We enumerate subleading contributions and estimate their magnitude. We also describe model-independent physical implications of this scenario. These include the masses of anomalous and non-anomalous U(1)'s and the generic existence of a new hyperweak force under which leptons and/or quarks could be charged. We propose that such a gauge boson could be responsible for the ghost muon anomaly recently found at the Tevatron's CDF detector.

  10. Ring relations and mirror map from branes

    Energy Technology Data Exchange (ETDEWEB)

    Assel, Benjamin [Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland)

    2017-03-29

    We study the space of vacua of three-dimensional N=4 theories from a novel approach building on the type IIB brane realization of the theory and in which the insertion of local chiral operators in the path integral is obtained from integrating out light modes in appropriate brane setups. Most of our analysis focuses on abelian quiver theories which can be realized as the low-energy theory of D3-D5-NS5 brane arrays. Their space of vacua contains a Higgs branch, parametrized by the vevs of half-BPS meson operators, and a Coulomb branch, parametrized by the vevs of half-BPS monopole operators. We show that the Higgs operators are inserted by adding F1 strings and D3 branes, while Coulomb operators are inserted by adding D1 strings and D3 branes, with specific orientations, to the initial brane setup of the theory. This approach has two main advantages. First the ring relations describing the Higgs and Coulomb branches can be derived by looking at specific brane setups with multiple interpretations in terms of operator insertions. This provides a new derivation of the Coulomb branch quantum relations. Secondly the map between the Higgs and Coulomb operators of mirror dual theories can be derived in a trivial way from IIB S-duality.

  11. Teleparallel loop quantum cosmology in a system of intersecting branes

    CERN Document Server

    Sepehri, Alireza; Beesham, A; de Haro, Jaume

    2016-01-01

    Recently, some authors have removed the big bang singularity in teleparallel Loop Quantum Cosmology (LQC) and have shown that the universe may undergo a number of oscillations. We investigate the origin of this type of teleparallel theory in a system of intersecting branes in M-theory in which the angle between them changes with time. This system is constructed by two intersecting anti-D8-branes, one compacted D4-brane and the other a D3-brane. These branes are built by joining M0-branes which develop in decaying fundamental strings. The compacted D4-brane is located between two intersecting anti-D8 branes and glues to one of them. Our universe is located on the D3 brane which wraps the D4 brane from one end and sticks to one of the anti-D8 branes from another one. In this system, there are three types of ?elds, corresponding to compacted D4 branes, intersecting branes and D3-branes. These ?elds interact with each other and make the angle between branes oscillate. By decreasing this angle and approaching the ...

  12. (Compactified black branes in four dimensional f(R-gravity

    Directory of Open Access Journals (Sweden)

    N. Dimakis

    2018-02-01

    Full Text Available A new family of analytical solutions in a four dimensional static spacetime is presented for f(R-gravity. In contrast to General Relativity, we find that a non trivial black brane/string solution is supported in vacuum power law f(R-gravity for appropriate values of the parameters characterizing the model and when axisymmetry is introduced in the line element. For the aforementioned solution, we perform a brief investigation over its basic thermodynamic quantities.

  13. (Compactified) black branes in four dimensional f(R)-gravity

    Science.gov (United States)

    Dimakis, N.; Giacomini, Alex; Paliathanasis, Andronikos

    2018-02-01

    A new family of analytical solutions in a four dimensional static spacetime is presented for f (R) -gravity. In contrast to General Relativity, we find that a non trivial black brane/string solution is supported in vacuum power law f (R) -gravity for appropriate values of the parameters characterizing the model and when axisymmetry is introduced in the line element. For the aforementioned solution, we perform a brief investigation over its basic thermodynamic quantities.

  14. Notes on unoriented D-brane instantons

    CERN Document Server

    Bianchi, Massimo

    2009-01-01

    In the first lecture, we discuss basic aspects of worldsheet and penta-brane instantons as well as (unoriented) D-brane instantons, which is our main focus here, and threshold corrections to BPS-saturated couplings. The second lecture is devoted to non-perturbative superpotentials generated by `gauge' and `exotic' instantons living on D3-branes at orientifold singularities. In the third lecture we discuss the interplay between worldsheet and D-string instantons on $T^4/Z_2$. We focus on a 4-fermi amplitude, give Heterotic and perturbative Type I descriptions, and offer a multi D-string instanton interpretation. We conclude with possible interesting developments.

  15. Branes at angles from worldvolume actions

    Directory of Open Access Journals (Sweden)

    Reza Abbaspur

    2016-05-01

    Full Text Available We investigate possible stable configurations of two arbitrary branes at general angles using the dynamics of DBI+WZ action. The analysis naturally reveals two types of solutions which we identify as the “marginal” and “non-marginal” configurations. We characterize possible configurations of a pair of identical or non-identical branes in either of these two classes by specifying their proper intersection rules and allowed intersection angles. We also perform a partial analysis of configurations with multiple angles of a system of asymptotically flat curved branes.

  16. Origami world

    Energy Technology Data Exchange (ETDEWEB)

    Kaloper, Nemanja E-mail: kaloper@solid.ucdavis.edu

    2004-05-01

    We paste together patches of AdS{sub 6} to find solutions which describe two 4-branes intersecting on a 3-brane with non-zero tension. We construct explicitly brane arrays with Minkowski, de Sitter and Anti-de Sitter geometries intrinsic to the 3-brane, and describe how to generalize these solutions to the case of AdS{sub 4+n,} n > 2, where n n+2-branes intersect on a 3-brane. The Minkowski and de Sitter solutions localize gravity to the intersection, leading to 4D Newtonian gravity at large distances. We show this explicitly in the case of Minkowski origami by finding the zero-mode graviton, and computing the couplings of the bulk gravitons to the matter on the intersection. In de Sitter case, this follows from the finiteness of the bulk volume. The effective 4D Planck scale depends on the square of the fundamental 6D Planck scale, the AdS{sub 6} radius and the angles between the 4-branes and the radial AdS direction, and for the Minkowski origami it is M{sub 4}{sup 2} = {l_brace}2/3{r_brace}(tan {alpha}{sub 1}+tan {alpha}{sub 2})M{sub *}{sup 4}L{sup 2}. If M{sub *} {approx} few x TeV this may account for the Planck-electroweak hierarchy even if L {approx} 10{sup -4}m, with a possibility for sub-millimeter corrections to the Newton's law. We comment on the early universe cosmology of such models. (author)

  17. Quantum billiards with branes on product of Einstein spaces

    Energy Technology Data Exchange (ETDEWEB)

    Ivashchuk, V.D. [VNIIMS, Center for Gravitation and Fundamental Metrology, Moscow (Russian Federation); Peoples' Friendship University of Russia, Institute of Gravitation and Cosmology, Moscow (Russian Federation)

    2016-05-15

    We consider a gravitational model in dimension D with several forms, l scalar fields and a Λ-term. We study cosmological-type block-diagonal metrics defined on a product of an 1-dimensional interval and n oriented Einstein spaces. As an electromagnetic composite brane ansatz is adopted and certain restrictions on the branes are imposed the conformally covariant Wheeler-DeWitt (WDW) equation for the model is studied. Under certain restrictions, asymptotic solutions to the WDW equation are found in the limit of the formation of the billiard walls. These solutions reduce the problem to the so-called quantum billiard in (n + l -1)-dimensional hyperbolic space. Several examples of quantum billiards in the model with electric and magnetic branes, e.g. corresponding to hyperbolic Kac-Moody algebras, are considered. In the case n = 2 we find a set of basis asymptotic solutions to the WDW equation and derive asymptotic solutions for the metric in the classical case. (orig.)

  18. Entanglement branes in a two-dimensional string theory

    Science.gov (United States)

    Donnelly, William; Wong, Gabriel

    2017-09-01

    What is the meaning of entanglement in a theory of extended objects such as strings? To address this question we consider the spatial entanglement between two intervals in the Gross-Taylor model, the string theory dual to two-dimensional Yang-Mills theory at large N . The string diagrams that contribute to the entanglement entropy describe open strings with endpoints anchored to the entangling surface, as first argued by Susskind. We develop a canonical theory of these open strings, and describe how closed strings are divided into open strings at the level of the Hilbert space. We derive the modular Hamiltonian for the Hartle-Hawking state and show that the corresponding reduced density matrix describes a thermal ensemble of open strings ending on an object at the entangling surface that we call an entanglement brane, or E-brane.

  19. Real-world validation of SHAC models

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, L.

    1970-01-01

    A statistical approach is proposed to validation of SHAC models. It includes a definition of validation, an explanation of its purposes, and a description of the statistical aspects of experimental design. It proposes a study to validate design codes with statistical samples of real-world systems. Also included is a summary of present SHAC validation methodologies and studies as well as recommendations for future activity.

  20. A mass hierarchy from recoiling D branes

    CERN Document Server

    Leontaris, G.K.

    2000-01-01

    Using conformal field theory methods we construct a metric that describes the distortion of space-time surrounding a D(irichlet)-brane (solitonic) defect after being struck by another D-brane. By viewing our four-dimensional universe as such a struck brane, embedded in a five-dimensional space-time, we argue on the appearance of a band of massive Kaluza-Klein excitations for the bulk graviton which is localized in a region of the fifth dimension determined by the inverse size of the band. The band incorporates the massless mode (ordinary graviton) and its thickness is determined essentially by the width of the Gaussian distribution describing the (target-space) quantum fluctuations of the intersecting-brane configuration.

  1. Wronskians, dualities and FZZT-Cardy branes

    Directory of Open Access Journals (Sweden)

    Chuan-Tsung Chan

    2016-09-01

    In this paper, we study generalized Wronskians of the Baker–Akhiezer systems as a manifestation of these new degrees of freedom. In particular, we derive their isomonodromy systems and then extend several spectral dualities to these systems. In addition, we discuss how these Wronskian operators are naturally aligned on the Kac table. Since they are consistent with the Seiberg–Shih relation, we propose that these new degrees of freedom can be identified as FZZT-Cardy branes in Liouville theory. This means that FZZT-Cardy branes are the bound states of elemental FZZT branes (i.e. the twisted fermions rather than the bound states of principal FZZT-brane (i.e. the resolvent operator.

  2. From Soft Walls to Infrared Branes

    CERN Document Server

    von Gersdorff, Gero

    2010-01-01

    Five dimensional warped spaces with soft walls are generalizations of the standard Randall-Sundrum compactifications, where instead of an infrared brane one has a curvature singularity (with vanishing warp factor) at finite proper distance in the bulk. We project the physics near the singularity onto a hypersurface located a small distance away from it in the bulk. This results in a completely equivalent description of the soft wall in terms of an effective infrared brane, hiding any singular point. We perform explicitly this calculation for two classes of soft wall backgrounds used in the literature. The procedure has several advantages. It separates in a clean way the physics of the soft wall from the physics of the five dimensional bulk, facilitating a more direct comparison with standard two-brane warped compactifications. Moreover, consistent soft walls show a sort of universal behavior near the singularity which is reflected in the effective brane Lagrangian. Thirdly, for many purposes, a good approxima...

  3. One-loop adjoint masses for branes at non-supersymmetric angles

    CERN Document Server

    Anastasopoulos, P; Benakli, K; Goodsell, M D; Vichi, A

    2012-01-01

    This proceeding is based on arXiv:1110.5359 [hep-th] where we consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by radiative corrections for the adjoint scalars on the brane world-volumes. In the open string channel, the string two-point function receives contributions only from the infrared limits of N~4 and N~2 supersymmetric configurations, via messengers and their Kaluza-Klein excitations, and leads at leading order to tachyonic directions.

  4. Funnel's Fluctuations in Dyonic Case: Intersecting D1-D3 Branes

    Directory of Open Access Journals (Sweden)

    Douari J.

    2007-07-01

    Full Text Available The fluctuations of funnel solutions of intersecting D1 and D3 branes are quite explicitly discussed by treating different modes and different directions of the fluctuation at the presence of world volume electric field. The boundary conditions are found to be Neumann boundary conditions.

  5. Spiked instantons from intersecting D-branes

    Directory of Open Access Journals (Sweden)

    Nikita Nekrasov

    2017-01-01

    Full Text Available The moduli space of spiked instantons that arises in the context of the BPS/CFT correspondence [22] is realised as the moduli space of classical vacua, i.e. low-energy open string field configurations, of a certain stack of intersecting D1-branes and D5-branes in Type IIB string theory. The presence of a constant B-field induces an interesting dynamics involving the tachyon condensation.

  6. Spiked instantons from intersecting D-branes

    Energy Technology Data Exchange (ETDEWEB)

    Nekrasov, Nikita, E-mail: nikitastring@gmail.com [Simons Center for Geometry and Physics, C.N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, NY 11794-3636 (United States); Prabhakar, Naveen S., E-mail: naveen.s.prabhakar@gmail.com [C.N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, NY 11794-3840 (United States)

    2017-01-15

    The moduli space of spiked instantons that arises in the context of the BPS/CFT correspondence is realised as the moduli space of classical vacua, i.e. low-energy open string field configurations, of a certain stack of intersecting D1-branes and D5-branes in Type IIB string theory. The presence of a constant B-field induces an interesting dynamics involving the tachyon condensation.

  7. Validating agent based models through virtual worlds.

    Energy Technology Data Exchange (ETDEWEB)

    Lakkaraju, Kiran; Whetzel, Jonathan H.; Lee, Jina; Bier, Asmeret Brooke; Cardona-Rivera, Rogelio E.; Bernstein, Jeremy Ray Rhythm

    2014-01-01

    As the US continues its vigilance against distributed, embedded threats, understanding the political and social structure of these groups becomes paramount for predicting and dis- rupting their attacks. Agent-based models (ABMs) serve as a powerful tool to study these groups. While the popularity of social network tools (e.g., Facebook, Twitter) has provided extensive communication data, there is a lack of ne-grained behavioral data with which to inform and validate existing ABMs. Virtual worlds, in particular massively multiplayer online games (MMOG), where large numbers of people interact within a complex environ- ment for long periods of time provide an alternative source of data. These environments provide a rich social environment where players engage in a variety of activities observed between real-world groups: collaborating and/or competing with other groups, conducting battles for scarce resources, and trading in a market economy. Strategies employed by player groups surprisingly re ect those seen in present-day con icts, where players use diplomacy or espionage as their means for accomplishing their goals. In this project, we propose to address the need for ne-grained behavioral data by acquiring and analyzing game data a commercial MMOG, referred to within this report as Game X. The goals of this research were: (1) devising toolsets for analyzing virtual world data to better inform the rules that govern a social ABM and (2) exploring how virtual worlds could serve as a source of data to validate ABMs established for analogous real-world phenomena. During this research, we studied certain patterns of group behavior to compliment social modeling e orts where a signi cant lack of detailed examples of observed phenomena exists. This report outlines our work examining group behaviors that underly what we have termed the Expression-To-Action (E2A) problem: determining the changes in social contact that lead individuals/groups to engage in a particular behavior

  8. Technical Naturalness on a Codimension-2 Brane

    CERN Document Server

    Burgess, C P; Tasinato, G

    2009-01-01

    We compute how threshold effects obtained by integrating out a heavy particle localized on a codimension-2 brane influence the properties of the brane and the bulk fields it sources in D=d+2 dimensions. We do so using a recently developed formalism for matching the characteristics of higher codimension branes to the properties of the bulk fields they source. We show that although the dominant dependence on a heavy mass M that is induced in the low-energy codimension-2 tension has the generic size expected, T_2 \\propto M^d, the very-low-energy effective potential governing the on-brane curvature once bulk KK modes are integrated out can be additionally suppressed, by factors of order k^2 M^d, where k is the bulk gravitational coupling. In the special case of a codimension-2 brane in a 6D supersymmetric bulk we also estimate the size of the contributions of short-wavelength bulk loops near the brane, and find these can be similarly suppressed.

  9. Intersecting Noncommutative M5-branes from Covariant Open Supermembrane

    OpenAIRE

    Sakaguchi, Makoto; Yoshida, Kentaroh

    2007-01-01

    We study intersecting noncommutative (NC) M5-branes from \\kappa-invariance of an open supermembrane action with constant three-form fluxes. The $\\kappa$-invariance gives rise to possible D-brane configurations for which projection operators can be determined. We construct projection operators for two types of 1/4 BPS intersecting NC M5-branes. The one is an intersection of two NC M5-branes: NC M5\\bot NC M5 (3). The other is that of a NC M5-brane and a commutative (C) M5-brane: NC M5\\bot C M5 ...

  10. Classical Solution for Ghost D-Branes in String Field Theory

    Directory of Open Access Journals (Sweden)

    Syoji Zeze

    2017-01-01

    Full Text Available Ghost D-branes have been proposed as objects that cancel the effects of D-branes. We construct a classical solution which represents an arbitrary number of D-branes and ghost D-branes in the context of open string field theory. Cancellation of BRST cohomology between D-branes and ghost D-branes is shown.

  11. Brane to brane gravity mediation of supersymmetry breaking

    CERN Document Server

    Rattazzi, Riccardo; Strumia, A; Rattazzi, Riccardo; Scrucca, Claudio A.; Strumia, Alessandro

    2003-01-01

    We extend the results of Mirabelli and Peskin to supergravity. We study the compactification on S_1/Z_2 of Zucker's off-shell formulation of 5D supergravity and its coupling to matter at the fixed points. We clarify some issues related to the off-shell description of supersymmetry breaking a la Scherk-Schwarz (here employed only as a technical tool) discussing how to deal with singular gravitino wave functions. We then consider `visible' and `hidden' chiral superfields localized at the two different fixed points and communicating only through 5D supergravity. We compute the one-loop corrections that mix the two sectors and the radion superfield. Locality in 5D ensures the calculability of these effects, which transmit supersymmetry breaking from the hidden to the visible sector. In the minimal set-up visible-sector scalars get a universal squared mass m_0^2 < 0. In general (e.g. in presence of a sizable gravitational kinetic term localized on the hidden brane) the radion-mediated contribution to m_0^2 can ...

  12. Defects and permutation branes in the Liouville field theory

    DEFF Research Database (Denmark)

    Sarkissian, Gor

    2009-01-01

    The defects and permutation branes for the Liouville field theory are considered. By exploiting cluster condition, equations satisfied by permutation branes and defects reflection amplitudes are obtained. It is shown that two types of solutions exist, discrete and continuous families....

  13. Non-commutative/non-associative IIA (IIB) geometries from Q- and R-branes and their intersections

    Science.gov (United States)

    Haßler, Falk; Lüst, Dieter

    2013-07-01

    In this paper we discuss the construction of non-geometric Q- and R-branes as sources of non-geometric Q- and R-fluxes in string compactifications. The non-geometric Q-branes, being obtained via T-duality from the NS 5-brane or respectively from the KK-monopole, are still local solutions of the standard NS action, where however the background fields G and B possess non-geometric global monodromy properties. We show that using double field theory and redefined background fields widetilde{G} and β as well as their corresponding effective action, the Q-branes are locally and globally well behaved solutions. Furthermore the R-brane solution can be at least formally constructed using dual coordinates. We derive the associated non-geometric Q- and R-fluxes and discuss that closed strings moving in the space transversal to the world-volumes of the non-geometric branes see a non-commutative or a non-associative geometry. In the second part of the paper we construct intersecting Q- and R-brane configurations as completely supersymmetric solutions of type IIA/B supergravity with certain SU(3) × SU(3) group structures. In the near horizon limit the intersecting brane configurations lead to type II backgrounds of the form AdS 4 × M 6, where the six-dimensional compact space M 6 is a torus fibration with various non-geometric Q- and R-fluxes in the compact directions. It exhibits an interesting non-commutative and non-associate geometric structure. Furthermore we also determine some of the effective four-dimensional superpotentials originating from the non-geometric fluxes.

  14. Formulation of D-brane Dynamics

    Science.gov (United States)

    Evans, Thomas

    2012-03-01

    It is the purpose of this paper (within the context of STS rules & guidelines ``research report'') to formulate a statistical-mechanical form of D-brane dynamics. We consider first the path integral formulation of quantum mechanics, and extend this to a path-integral formulation of D-brane mechanics, summing over all the possible path integral sectors of R-R, NS charged states. We then investigate this generalization utilizing a path-integral formulation summing over all the possible path integral sectors of R-R charged states, calculated from the mean probability tree-level amplitude of type I, IIA, and IIB strings, serving as a generalization of all strings described by D-branes. We utilize this generalization to study black holes in regimes where the initial D-brane system is legitimate, and further this generalization to look at information loss near regions of nonlocality on a non-ordinary event horizon. We see here that in these specific regimes, we can calculate a path integral formulation, as describing D0-brane mechanics, tracing the dissipation of entropy throughout the event horizon. This is used to study the information paradox, and to propose a resolution between the phenomena and the correct and expected quantum mechanical description. This is done as our path integral throughout entropy entering the event horizon effectively and correctly encodes the initial state in subtle correlations in the Hawking radiation.

  15. Decoupling of gravity on non-susy Dp branes

    Energy Technology Data Exchange (ETDEWEB)

    Nayek, Kuntal; Roy, Shibaji [Saha Institute of Nuclear Physics,1/AF Bidhannagar, Calcutta, 700064 (India)

    2016-03-15

    We study the graviton scattering in the background of non-susy Dp branes of type II string theories consisting of a metric, a dilaton and a (p+1) form gauge field. We show numerically that in these backgrounds graviton experiences a scattering potential which takes the form of an infinite barrier in the low energy (near brane) limit for p≤5 and therefore is never able to reach the branes. This shows, contrary to what is known in the literature, that gravity indeed decouples from the non-susy Dp branes for p≤5. For non-susy D6 brane, gravity couples as there is no such barrier for the potential. To give further credence to our claim we solve the scattering equation in some situation analytically and calculate the graviton absorption cross-sections on the non-susy branes and show that they vanish for p≤4 in the low energy limit. This shows, as in the case of BPS branes, that gravity does decouple for non-susy Dp branes for p≤4 but it does not decouple for D6 brane as the potential here is always attractive. We argue for the non-susy D5 brane that depending on one of the parameters of the solution gravity either always decouples (unlike the BPS D5 brane) or it decouples when the energy of the graviton is below certain critical value, otherwise it couples, very similar to BPS D5 brane.

  16. Considering Late-Time Acceleration in Some Cosmological Models

    Directory of Open Access Journals (Sweden)

    S. Davood Sadatian

    2013-01-01

    Full Text Available We study two cosmological models: a nonminimally coupled scalar field on brane world model and a minimally coupled scalar field on Lorentz invariance violation model. We compare some cosmological results in these scenarios. Also, we consider some types of Rip singularity solution in both models.

  17. Cosmology from quantum potential in a system of oscillating branes

    Science.gov (United States)

    Sepehri, Alireza

    2016-11-01

    Recently, some authors proposed a new mechanism which gets rid of the Big Bang singularity and shows that the age of the universe is infinite. In this paper, we will confirm their results and predict that the universe may expand and contract many N fundamental strings decay to N M0-anti-M0-branes. Then, M0-branes join each other and build a M8-anti-M8 system. This system is unstable, broken and two anti-M4-branes, a compactified M4-brane, a M3-brane in addition to one M0-brane are produced. The M3-brane wraps around the compactified M4-brane and both of them oscillate between two anti-M4-branes. Our universe is located on the M3-brane and interacts with other branes by exchanging the M0-brane and some scalars in transverse directions. By wrapping of M3-brane, the contraction epoch of universe starts and some higher order of derivatives of scalar fields in the relevant action of branes are produced which are responsible for generating the generalized uncertainty principle (GUP). By oscillating the compactified M4-M3-brane and approaching one of anti-M4-branes, one end of M3-brane glues to the anti-M4-brane and other end remains sticking and wrapping around M4-brane. Then, by getting away of the M4-M3 system, M4 rolls, wrapped M3 opens and expansion epoch of universe begins. By closing the M4 to anti-M4, the mass of some scalars become negative and they make a transition to tachyonic phase. To remove these states, M4 rebounds, rolls and M3 wraps around it again. At this stage, expansion branch ends and universe enters a contraction epoch again. This process is repeated many times and universe expands and contracts due to oscillation of branes. We obtain the scale factor of universe in this system and find that its values only at t →-∞ shrinks to zero. Thus, in our method, the Big Bang is replaced by the fundamental string and the age of universe is predicted to be infinite. Also, when tachyonic states disappear at the beginning of expansion branch, some extra

  18. On Brane Solutions Related to Non-Singular Kac-Moody Algebras

    Directory of Open Access Journals (Sweden)

    Vladimir D. Ivashchuk

    2009-07-01

    Full Text Available A multidimensional gravitational model containing scalar fields and antisymmetric forms is considered. The manifold is chosen in the form M = M_0 × M_1 × ... × M_n, where M_i are Einstein spaces (i ≥ 1. The sigma-model approach and exact solutions with intersecting composite branes (e.g. solutions with harmonic functions, S-brane and black brane ones with intersection rules related to non-singular Kac-Moody (KM algebras (e.g. hyperbolic ones are reviewed. Some examples of solutions, e.g. corresponding to hyperbolic KM algebras: H_2(q,q, AE3, HA_2^{(1}, E_{10} and Lorentzian KM algebra P_{10} are presented.

  19. Induced higher-derivative massive gravity on a 2-brane in 4D Minkowski space

    Directory of Open Access Journals (Sweden)

    D. Bazeia

    2015-03-01

    Full Text Available In this paper we revisit the problem of localizing gravity in a 2-brane embedded in a 4D Minkowski space to address induction of high derivative massive gravity. We explore the structure of propagators to find well-behaved higher-derivative massive gravity induced on the brane. Exploring a special case in the generalized mass term of the graviton propagator we find a model of consistent higher order gravity with an additional unitary massive spin-2 particle and two massless particles: one spin-0 particle and one spin-1 particle. The condition for the absence of tachyons is satisfied for both ‘right’ and ‘wrong’ signs of the Einstein–Hilbert term on the 2-brane. We also find the Pauli–Fierz mass term added to the new massive gravity in three dimensions and recover the low-dimensional DGP model.

  20. Non-geometric branes are DFT monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Bakhmatov, Ilya [Kazan Federal University, Institute of Physics, General Relativity Department,Kremlevskaya 16a, 420111, Kazan (Russian Federation); Kleinschmidt, Axel [Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut),Am Mühlenberg 1, DE-14476 Potsdam (Germany); International Solvay Institutes,Campus Plaine C.P. 231, Boulevard du Triomphe, 1050 Bruxelles (Belgium); Musaev, Edvard T. [Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut),Am Mühlenberg 1, DE-14476 Potsdam (Germany); Kazan Federal University, Institute of Physics, General Relativity Department,Kremlevskaya 16a, 420111, Kazan (Russian Federation)

    2016-10-14

    The double field theory monopole solution by Berman and Rudolph is shown to reproduce non-geometric backgrounds with non-vanishing Q- and R-flux upon an appropriate choice of physical and dual coordinates. The obtained backgrounds depend non-trivially on dual coordinates and have only trivial monodromies. Upon smearing the solutions along the dual coordinates one reproduces the known 5{sub 2}{sup 2} solution for the Q-brane and co-dimension 1 solution for the R-brane. The T-duality invariant magnetic charge is explicitly calculated for all these backgrounds and is found to be equal to the magnetic charge of (unsmeared) NS5-brane.

  1. Non-Lagrangian theories from brane junctions

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Ling [Chalmers Univ. of Technology, Goeteborg (Sweden); Mitev, Vladimir [Humboldt Univ., Berlin (Germany). Inst. fuer Mathematik und Inst. fuer Physik; Pomoni, Elli [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany). Theory Group; Taki, Masato [RIKEN Nishina Center, Saitama (Japan). Mathematical Physics Lab.; Yagi, Futoshi [International School of Advanced Studies (SISSA), Trieste (Italy); INFN, Trieste (Italy); Korea Institute for Advanced Study (KIAS), Seoul (Korea, Republic of)

    2013-10-15

    In this article we use 5-brane junctions to study the 5D T{sub N} SCFTs corresponding to the 5D N=1 uplift of the 4D N=2 strongly coupled gauge theories, which are obtained by compactifying N M5 branes on a sphere with three full punctures. Even though these theories have no Lagrangian description, by using the 5-brane junctions proposed by Benini, Benvenuti and Tachikawa, we are able to derive their Seiberg-Witten curves and Nekrasov partition functions. We cross-check our results with the 5D superconformal index proposed by Kim, Kim and Lee. Through the AGTW correspondence, we discuss the relations between 5D superconformal indices and n-point functions of the q-deformed W{sub N} Toda theories.

  2. Universal turbulence on branes in holography

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Koji; Nishida, Mitsuhiro; Sonoda, Akihiko [Department of Physics, Osaka University,Toyonaka, Osaka 560-0043 (Japan)

    2015-08-27

    At a meson melting transition in holographic QCD, a weak turbulence of mesons was found with critical embeddings of probe D-branes in gravity duals. The turbulent mesons have a power-law energy distribution ε{sub n}∝(ω{sub n}){sup α} where ω{sub n} is the mass of the n-th excited resonance of the meson tower. In this paper, we find that the turbulence power α is universal, irrespective of how the transition is driven, by numerically calculating the power in various static brane setups at criticality. We also find that the power α depends only on the cone dimensions of the probe D-branes.

  3. Branes and the Kraft-Procesi transition

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, Santiago; Hanany, Amihay [Theoretical Physics, The Blackett Laboratory, Imperial College London,SW7 2AZ United Kingdom (United Kingdom)

    2016-11-29

    The Coulomb and Higgs branches of certain 3d N=4 gauge theories can be understood as closures of nilpotent orbits. Recently, a new theorem by Namikawa suggests that this is the simplest possible case, thus giving this class a special role. In this note we use branes to reproduce the mathematical work by Kraft and Procesi. It studies the classification of all nilpotent orbits for classical groups and it characterizes an inclusion relation via minimal singularities. We show how these minimal singularities arise naturally in the Type IIB superstring embedding of the 3d A-type theories. The Higgs mechanism can be used to remove the minimal singularity, corresponding to a transition in the brane configuration that induces a new effective 3d theory. This reproduces the Kraft-Procesi results, endowing the family of gauge theories with a new underlying structure. We provide an efficient procedure for computing such brane transitions.

  4. A closer look at two AdS{sub 4} branes in an AdS{sub 5} bulk

    Energy Technology Data Exchange (ETDEWEB)

    Thambyahpillai, Shiyamala [Harvard University, Department of Pysics, Cambridge, Massachusetts (United States)]. E-mail: thamby@physics.harvard.edu

    2005-02-01

    We investigate a scenario with two AdS{sub 4} branes in an AdS{sub 5} bulk. In this scenario there are two gravitons and we investigate the role played by each of them for different positions of the second brane. We show that both gravitons play a significant role only when the turn-around point in the warp factor is approximately equidistant from both branes. We find that the ultralight mode becomes heavy as the second brane approaches the turn-around point, and the physics begins to resemble that of the RS model. Thus we demonstrate the crucial role played by the turn-around in the warp factor in enabling the presence of both gravitons. (author)

  5. Cosmological evolution with brane-bulk energy exchange

    CERN Document Server

    Kiritsis, Elias B; Tetradis, N; Tomaras, T N; Zarikas, V

    2003-01-01

    The consequences for the brane cosmological evolution of energy exchange between the brane and the bulk are analysed in detail, in the context of a non-factorizable background geometry with vanishing effective cosmological constant on the brane. A rich variety of brane cosmologies is obtained, depending on the precise mechanism of energy transfer, the equation of state of brane-matter and the spatial topology. An accelerating era is generically a feature of our solutions. In the case of low-density flat universe more dark matter than in the conventional FRW picture is predicted. Spatially compact solutions are found to delay their recollapse.

  6. D-Branes in the Background of NS Fivebranes

    CERN Document Server

    Elitzur, Shmuel; Rabinovici, Eliezer; Sarkisian, G; Kutasov, D; Elitzur, Shmuel; Giveon, Amit; Kutasov, David; Rabinovici, Eliezer; Sarkissian, Gor

    2000-01-01

    We study the dynamics of $D$-branes in the near-horizon geometry of $NS$ fivebranes. This leads to a holographically dual description of the physics of $D$-branes ending on and/or intersecting $NS5$-branes. We use it to verify some properties of such $D$-branes which were deduced indirectly in the past, and discuss some instabilities of non-supersymmetric brane configurations. Our construction also describes vacua of Little String Theory which are dual to open plus closed string theory in asymptotically linear dilaton spacetimes.

  7. Holomorphic Corrections from Wrapped Euclidean Branes

    CERN Document Server

    Petersson, Christoffer

    2009-01-01

    We discuss how non-perturbative corrections to the four-dimensional effective superpotential are generated by wrapped Euclidean D-branes. It is shown how such terms can be computed and we give a few examples of holomorphic couplings that arise from a D-brane instanton effect in string theory. Some of these instanton configurations give rise to phenomenologically desirable couplings although they do not admit an obvious interpretation in terms of standard gauge theory. This note is based on [R. Argurio, M. Bertolini, G. Ferretti, A. Lerda and C. Petersson, JHEP 0706, 067 (2007) [arXiv:0704.0262 [hep-th

  8. Brane solutions sourced by a scalar with vanishing potential and classification of scalar branes

    Energy Technology Data Exchange (ETDEWEB)

    Cadoni, Mariano [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); Franzin, Edgardo [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Serra, Matteo [Dipartimento di Matematica, Sapienza Università di Roma,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-01-20

    We derive exact brane solutions of minimally coupled Einstein-Maxwell-scalar gravity in d+2 dimensions with a vanishing scalar potential and we show that these solutions are conformal to the Lifshitz spacetime whose dual QFT is characterized by hyperscaling violation. These solutions, together with the AdS brane and the domain wall sourced by an exponential potential, give the complete list of scalar branes sourced by a generic potential having simple (scale-covariant) scaling symmetries not involving Galilean boosts. This allows us to give a classification of both simple and interpolating brane solution of minimally coupled Einstein-Maxwell-scalar gravity having no Schrödinger isometries, which may be very useful for holographic applications.

  9. T-branes through 3d mirror symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Collinucci, Andrés; Giacomelli, Simone [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Bruxelles (Belgium); Savelli, Raffaele [Institut de Physique Théorique, CEA Saclay,Orme de Merisiers, F-91191 Gif-sur-Yvette (France); Valandro, Roberto [Dipartimento di Fisica, Università di Trieste,Strada Costiera 11, 34151 Trieste (Italy); INFN, Sezione di Trieste,Via Valerio 2, 34127 Trieste (Italy); Abdus Salam International Centre for Theoretical Physics,Strada Costiera 11, 34151 Trieste (Italy)

    2016-07-19

    T-branes are exotic bound states of D-branes, characterized by mutually non-commuting vacuum expectation values for the worldvolume scalars. The M/F-theory geometry lifting D6/D7-brane configurations is blind to the T-brane data. In this paper, we make this data manifest, by probing the geometry with an M2-brane. We find that the effect of a T-brane is to deform the membrane worldvolume superpotential with monopole operators, which partially break the three-dimensional flavor symmetry, and reduce supersymmetry from N=4 to N=2. Our main tool is 3d mirror symmetry. Through this language, a very concrete framework is developed for understanding T-branes in M-theory. This leads us to uncover a new class of N=2 quiver gauge theories, whose Higgs branches mimic those of membranes at ADE singularities, but whose Coulomb branches differ from their N=4 counterparts.

  10. Intersections of S-branes with waves and monopoles

    Directory of Open Access Journals (Sweden)

    Mert Besken

    2015-05-01

    Full Text Available We construct intersections of S-branes with waves and Kaluza–Klein monopoles. There are several possible ways to add a monopole to an S-brane solution similar to p-branes. On the other hand, one may add a wave only to the transverse space of an S-brane unlike a p-brane where wave resides on its worldvolume. The metric function of the wave is a harmonic function of the remaining transverse directions and an extra condition on integration constants is needed. We also show that it is not possible to add an S-brane to p-brane intersections whose near horizon geometry has an AdS part.

  11. Dynamical formation of horizons in recoiling D-branes

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, Dimitri V

    2000-01-01

    A toy calculation of string or D-particle interactions within a world-sheet approach indicates that quantum recoil effects-reflecting the gravitational back reaction on space-time foam due to the propagation of energetic particles-induces the appearance of a microscopic event horizon, or "bubble, " inside which stable matter can exist. The scattering event causes this horizon to expand, but we expect quantum effects to cause it to contract again, in a "bounce" solution. Within such "bubbles, " massless matter propagates with an effective velocity that is less than the velocity of light in vacuo, which may lead to observable violations of Lorentz symmetry that may be tested experimentally. The conformal invariance conditions in the interior geometry of the bubbles select preferentially 3 for the number of the spatial dimensions, corresponding to a consistent formulation of the interaction of D3-branes with recoiling D particles, which are allowed to fluctuate independently only on the D3-brane hypersurface. (2...

  12. BPS soliton solutions of a D3-brane action

    Science.gov (United States)

    Schwarz, John H.

    2014-07-01

    The world-volume action of a probe D3-brane in AdS 5 × S 5 with N units of flux has the field content, symmetries, and dualities of the U(1) factor of = 4 U( N + 1) super Yang-Mills theory, spontaneously broken to U( N) × U(1) by being on the Coulomb branch, with the massive fields integrated out. Thus, it might be the exact effective action (a highly effective action), or else a useful approximation to it. We construct an SL(2, ℤ) multiplet of BPS soliton solutions of the D3-brane action and show that in the N = 1 case they correspond to the electrically charged states that have been integrated out as well as magnetic monopoles and dyons. Their charges are uniformly spread on a spherical surface, a soliton bubble, which can be interpreted as a phase boundary. This picture is consistent with previous results in the string theory and field theory literature.

  13. D-instanton and polyinstanton effects from type I' D0-brane loops

    CERN Document Server

    Petersson, Christoffer; Uranga, Angel M

    2010-01-01

    We study non-perturbative D(-1)-instanton corrections to quartic gauge and curvature couplings in 8d type IIB orientifolds, in terms of a one-loop computation of BPS D0-branes in T-dual type I' models. The complete perturbative and non-perturbative results are determined by the BPS multiplicities of perturbative open strings and D0-brane bound states in the 9d type I' theory. Its modular properties admit a geometric interpretation by lifting to Horava-Witten theory. We use the type I' viewpoint to motivate a proper interpretation of 8d and 4d polyinstanton effects, consistent with heterotic - type II orientifold duality.

  14. The OURSE model: Simulating the World Refining Sector to 2030

    OpenAIRE

    LANTZ Frédéric; SAINT-ANTONIN Valérie; Gruson, Jean-François; SUWALA Wojciech

    2012-01-01

    The development of a model of the World Refining for the POLES model aims to represent the oil product's supply at a world-wide level in a global energy model. The World oil refining industry faces to several challenges such as the increasing oil derivatives demand in the transport sector, the improvement of the specifications of these products, the crude oil availability and the limitation of carbon emissions. An aggregated refining model linked to the POLES energy model has been developed t...

  15. First Law of p-brane Thermodynamics

    OpenAIRE

    Rogatko, Marek

    2009-01-01

    We study the physical process version and the equilibrium state version of the first law of thermodynamics for a charged p-brane. the general setting for our investigations is (n+p+1)-dimensional Einstein dilaton gravity with (p+2) strength form fields.

  16. Collective excitations of massive flavor branes

    Directory of Open Access Journals (Sweden)

    Georgios Itsios

    2016-08-01

    Full Text Available We study the intersections of two sets of D-branes of different dimensionalities. This configuration is dual to a supersymmetric gauge theory with flavor hypermultiplets in the fundamental representation of the gauge group which live on the defect of the unflavored theory determined by the directions common to the two types of branes. One set of branes is dual to the color degrees of freedom, while the other set adds flavor to the system. We work in the quenched approximation, i.e., where the flavor branes are considered as probes, and focus specifically on the case in which the quarks are massive. We study the thermodynamics and the speeds of first and zero sound at zero temperature and non-vanishing chemical potential. We show that the system undergoes a quantum phase transition when the chemical potential approaches its minimal value and we obtain the corresponding non-relativistic critical exponents that characterize its critical behavior. In the case of (2+1-dimensional intersections, we further study alternative quantization and the zero sound of the resulting anyonic fluid. We finally extend these results to non-zero temperature and magnetic field and compute the diffusion constant in the hydrodynamic regime. The numerical results we find match the predictions by the Einstein relation.

  17. Branes in Gravity's Rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Ashour, Amani [Damascus University, Mathematics Department, Faculty of Science, Damascus (Syrian Arab Republic); Faizal, Mir [University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Ali, Ahmed Farag [Benha University, Department of Physics, Faculty of Science, Benha (Egypt); Hammad, Faycal [Bishop' s University, Physics Department and STAR Research Cluster, Sherbrooke, QC (Canada); Champlain College-Lennoxville, Physics Department, Sherbrooke, QC (Canada)

    2016-05-15

    In this work, we investigate the thermodynamics of black p-branes (BB) in the context of Gravity's Rainbow. We investigate this using rainbow functions that have been motivated from loop quantum gravity and κ-Minkowski non-commutative spacetime. Then for the sake of comparison, we examine a couple of other rainbow functions that have also appeared in the literature. We show that, for consistency, Gravity's Rainbow imposes a constraint on the minimum mass of the BB, a constraint that we interpret here as implying the existence of a black p-brane remnant. This interpretation is supported by the computation of the black p-brane's heat capacity that shows that the latter vanishes when the Schwarzschild radius takes on a value that is bigger than its extremal limit. We found that the same conclusion is reached for the third version of rainbow functions treated here but not with the second one for which only standard black p-brane thermodynamics is recovered. (orig.)

  18. scalar field dynamics on a brane

    Indian Academy of Sciences (India)

    power-law potential V ~φa is investigated. We describe solutions for which the scalar field energy density scales as a power-law of the scale factor. We also describe solutions existing in regions of the parameter space where these scaling solutions are unstable or do not exist. Keywords. Brane; scalar field; scaling solution.

  19. Phenomenological analysis of D-brane Pati-Salam vacua

    CERN Document Server

    Anastasopoulos, P.; Vlachos, N.D.

    2010-01-01

    In the present work we perform a phenomenological analysis of the effective low energy models with Pati-Salam (PS) gauge symmetry derived in the context of D-branes. A main issue in these models arises from the fact that the right-handed fermions and the PS-symmetry breaking Higgs field transform identically under the PS symmetry, causing unnatural matter-Higgs mixing effects. We argue that this problem could be solved in particular D-brane setups where these fields arise in different intersections. We further observe that whenever a large Higgs mass term is generated in a particular class of mass spectra, a splitting mechanism -reminiscent of the doublet triplet splitting- may protect the neutral Higgs components from a heavy mass term. We analyze the implications of each individual representation which in principle is available in these models in order to specify the minimal spectrum required to build up a consistent PS model which reconciles the low energy data. A short discussion is devoted on the effects...

  20. LgrbWorldModel: Long-duration Gamma-Ray Burst World Model

    Science.gov (United States)

    Shahmoradi, Amir; Nemiroff, Robert J.

    2017-12-01

    LgrbWorldModel is written in Fortran 90 and attempts to model the population distribution of the Long-duration class of Gamma-Ray Bursts (LGRBs) as detected by the NASA's now-defunct Burst And Transient Source Experiment (BATSE) onboard the Compton Gamma Ray Observatory (CGRO). It is assumed that the population distribution of LGRBs is well fit by a multivariate log-normal distribution. The best-fit parameters of the distribution are then found by maximizing the likelihood of the observed data by BATSE detectors via a native built-in Adaptive Metropolis-Hastings Markov-Chain Monte Carlo (AMH-MCMC) Sampler.

  1. On RR couplings and bulk singularity structures of non-BPS branes

    Directory of Open Access Journals (Sweden)

    Ehsan Hatefi

    2016-09-01

    Full Text Available We compute the five point world sheet scattering amplitude of a symmetric closed string Ramond–Ramond, a transverse scalar field, a world volume gauge field and a real tachyon in both world volume and transverse directions of brane in type IIA and IIB superstring theory. We provide the complete analysis of S-matrix and show that both u′=u+14 and t channel bulk singularity structures can also be examined by this S-matrix. Various remarks about new restricted Bianchi identities on world volume for the other pictures have also been made.

  2. Tree Level Potential on Brane after Planck and BICEP2 M. Ferricha ...

    Indian Academy of Sciences (India)

    , we propose a study of the tree level poten- tial inflation in the framework of the Randall–Sundrum type-2 braneworld model. We focus on three branches of the potential, where we evaluate some values of brane tension λ. We discuss how the ...

  3. D-brane charge, flux quantization and relative (co)homology

    NARCIS (Netherlands)

    Figueroa-O'Farrill, J.M.; Stanciu, S.

    2001-01-01

    We reconsider the problem of U(1) flux and D0-charge for D-branes in the WZW model and investigate the relationship between the different definitions that have been proposed recently. We identify the D0-charge as a particular reduction of a class in the relative cohomology of the group modulo the

  4. SgrbWorldModel: Short-duration Gamma-Ray Burst World Model

    Science.gov (United States)

    Shahmoradi, Amir; Nemiroff, Robert J.

    2017-12-01

    SgrbWorldModel, written in Fortran 90, presents an attempt at modeling the population distribution of the Short-duration class of Gamma-Ray Bursts (SGRBs) as detected by the NASA's now-defunct Burst And Transient Source Experiment (BATSE) onboard the Compton Gamma Ray Observatory (CGRO). It is assumed that the population distribution of SGRBs is well fit by a multivariate log-normal distribution, whose differential cosmological rate of occurrence follows the Star-Formation-Rate (SFR) convolved with a log-normal binary-merger delay-time distribution. The best-fit parameters of the model are then found by maximizing the likelihood of the observed data by the BATSE detectors via a native built-in Adaptive Metropolis-Hastings Markov-Chain Monte Carlo (AMH-MCMC)Sampler that is part of the code. A model for the detection algorithm of the BATSE detectors is also provided.

  5. Models of the World human population growth- critical analysis

    OpenAIRE

    Golosovsky, Michael

    2009-01-01

    We analyze mathematical models of the global human population growth and compare them to actual dynamics of the world population and of the world surplus product. We consider a possibility that the so-called world's demographic transition is not a dynamic crossover but a phase transition that affects all aspects of our life.

  6. Randall-Sundrum brane cosmology: modification of late-time cosmic dynamics by exotic matter

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Salcedo, Ricardo [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada Legaria del IPN, Mexico DF (Mexico); Gonzalez, Tame [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzadas del IPN, A.P.14-740, 07000, Mexico DF (Mexico); Moreno, Claudia [Departamento de Fisica y Matematicas, Centro Universitario de Ciencias Exactas e Ingenierias, Corregidora 500 SR, Universidad de Guadalajara, 44420 Guadalajara, Jalisco (Mexico); Quiros, Israel, E-mail: rigarcias@ipn.mx, E-mail: tamegc72@gmail.com, E-mail: claudia.moreno@cucei.udg.mx, E-mail: iquiros@fisica.ugto.mx [Division de Ciencias e IngenierIa de la Universidad de Guanajuato, AP 150, 37150, Leon, Guanajuato (Mexico)

    2011-05-21

    In this paper we show, through the study of concrete examples, that depending on the cosmic dynamics of the energy density of matter degrees of freedom living in the brane, Randall-Sundrum (RS) brane effects can be important not only at short distances (UV regime), but also at large cosmological scales (IR regime). Our first example relies on the study, by means of the dynamical system tools, of a toy model based in a nonlinear electrodynamics (NLED) Lagrangian. Then we show that other, less elaborated models, such as the inclusion of a scalar phantom field, and of a tachyon phantom field-trapped in the brane-produce similar results. The form of the RS correction seems to convert what would have been future attractors in general relativity into saddle points. The above 'mixing of scales' effect is distinctive only of theories that modify the right-hand side (matter part) of the Friedmann equation, so that, for instance, Dvali-Gabadadze-Porrati-brane models do not show this feature.

  7. Conformal Maxwell Theory as a Singleton Field Theory on $ADS_{5}$, IIB Three Branes and Duality

    CERN Document Server

    Ferrara, Sergio

    1998-01-01

    We examine the boundary conditions associated with extended supersymmetric Maxwell theory in 5-dimensional anti-De Sitter space. Excitations on the boundary are identical to those of ordinary 4-dimensional conformal invariant super electrodynammics. Extrapolations of these excitations give rise to a 5-dimensional topological gauge theory of the singleton type. The possibility of a connection of this phenomenon to the world volume theory of 3-branes in IIB string theory is discussed.

  8. Strings, branes and extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Quevedo, Fernando

    2004-12-01

    In an attempt to gain a better understanding of our world, various philosophers, mathematicians and physicists have, over the last few centuries, proposed that we might live in a world with more than four space-time dimensions. In the 17th century, for example, Emmanuel Kant tried to figure out what is special about a three spatial-dimensional world. He concluded that there could be other universes hidden from our senses - an idea that Democritus among others had also entertained. (U.K.)

  9. On the Microscopic Perspective of Black Branes Thermodynamic Geometry

    Directory of Open Access Journals (Sweden)

    Stefano Bellucci

    2010-09-01

    Full Text Available We study thermodynamic state-space geometry of the black holes in string theory and M-theory. For a large number of microstates, we analyze the intrinsic state-space geometry for (i extremal and non-extremal black branes in string theory, (ii multi-centered black brane configurations, (iv small black holes with fractional branes, and (v fuzzy rings in the setup of Mathur’s fuzzballs and subensemble theory. We extend our analysis for the black brane foams and bubbling black brane solutions in M-theory. We discuss the nature of state-space correlations of various black brane configurations, and show that the notion of state-space manifolds describes the associated coarse-grained interactions of the corresponding microscopic CFT data.

  10. A Novel Mass Hierarchy and Discrete Excitation Spectra from Quantum-Fluctuating D-branes

    CERN Document Server

    Leontaris, G.K.

    2001-01-01

    We elaborate further on a recently proposed scenario for generating a mass hierarchy through quantum fluctuations of a single D3 brane, which represents our world embedded in a bulk five-dimensional space time. In this scenario, the quantum fluctuations of the D3-brane world in the bulk direction, quantified to leading order via a `recoil' world-sheet logarithmic conformal field theory approach, result in the dynamical appearance of a supersymmetry breaking (obstruction) scale alpha. This may be naturally taken to be at the TeV range, in order to provide a solution to the conventional gauge-hierarchy problem. The bulk spatial direction is characterized by the dynamical appearance of an horizon located at +- 1/alpha, inside which the positive energy conditions for the existence of stable matter are satisfied. To ensure the correct value of the four-dimensional Planck mass, the bulk string scale M_s is naturally found to lie at an intermediate energy scale of 10^{14} GeV. As an exclusive feature of the D3-brane...

  11. Isolated Minkowski vacua, and stability analysis for an extended brane in the rugby ball

    Science.gov (United States)

    Himmetoǧlu, Burak; Peloso, Marco

    2007-06-01

    We study a recently proposed model, where a codimension one brane is wrapped around the axis of symmetry of an internal two-dimensional space compactified by a flux. This construction is free from the problems which plague delta-like, codimension two branes, where only tension can be present. In contrast, arbitrary fields can be localized on this extended brane, and their gravitational interaction is standard 4d gravity at large distances. In the first part of this work, we study the de Sitter (dS) vacua of the model. The landscape of these vacua is characterized by discrete points labeled by two integer numbers, related to the flux responsible for the compactification and to the current of a brane field. A Minkowski external space emerges only for a special ratio between these two integers, and it is therefore (topologically) isolated from the nearby dS solutions. In the second part, we show that the Minkowski vacua are stable under the most generic axially-symmetric perturbations, and we argue that this is sufficient to ensure the overall stability.

  12. Emergence of the world with Lie-N-algebra and M-dimensions from nothing

    CERN Document Server

    Sepehri, Alireza

    2016-01-01

    In this paper, we propose a new model in Lie-N-algebra that removes big bang singularity and produces the world with all it's objects and dimensions from nothing. We name this theory as G(God)-theory. In this model, first, two types of energies with opposite signs are produced from nothing such as the sum over them be zero. They create two types of branes with opposite quantum numbers which interact with each other by exchanging bosonic tensor fields like graviton and compact. By compacting branes, fermionic tensor fields are emerged which some of them play the role of the gravitinos. Also, some dimensions take extra (i) factors, their properties become different and they behave like time dimensions. Gravitons and gravitinos create two types of wormholes which lead to the oscillation of branes between expansion and contracting branches. These wormholes produce a repulsive gravity in compacted branes and cause that their particles get away from each other and expansion branch begin. Also, they create an attrac...

  13. Metastable Vacua and D-branes at the Conifold

    Energy Technology Data Exchange (ETDEWEB)

    Argurio, Riccardo; /Brussels U., PTM /Intl. Solvay Inst., Brussels; Bertolini, Matteo; /SISSA, Trieste /INFN, Trieste; Franco, Sebastian; /Princeton U.; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC

    2007-04-04

    We consider quiver gauge theories arising on D-branes at simple Calabi-Yau singularities (quotients of the conifold). These theories have metastable supersymmetry breaking vacua. The field theoretic mechanism is basically the one exhibited by the examples of Intriligator, Seiberg and Shih in SUSY QCD. In a dual description, the SUSY breaking is captured by the presence of anti-branes. In comparison to our earlier related work, the main improvements of the present construction are that we can reach the free magnetic range of the SUSY QCD theory where the existence of the metastable vacua is on firm footing, and we can see explicitly how the small masses for the quark flavors (necessary to the existence of the SUSY breaking vacua) are dynamically stabilized. One crucial mass term is generated by a stringy instanton. Finally, our models naturally incorporate R-symmetry breaking in the non-supersymmetric vacuum, in a way similar to the examples of Kitano, Ooguri and Ookouchi.

  14. Non-Abelian phenomena on D-branes

    CERN Document Server

    Myers, R

    2003-01-01

    A remarkable feature of D-branes is the appearance of a non-Abelian gauge theory in the description of several (nearly) coincident branes. This non-Abelian structure plays an important role in realizing various geometric effects with D-branes. In particular, the branes' transverse displacements are described by matrix-valued scalar fields and so noncommutative geometry naturally appears in this framework. I review the action governing this non-Abelian theory, as well as various related physical phenomena such as the dielectric effect, giant gravitons and fuzzy funnels.

  15. Relativistic elasticity of stationary fluid branes

    DEFF Research Database (Denmark)

    Armas, J.; Obers, N.A.

    2013-01-01

    Fluid mechanics can be formulated on dynamical surfaces of arbitrary codimension embedded in a background space-time. This has been the main object of study of the blackfold approach in which the emphasis has primarily been on stationary fluid configurations. Motivated by this approach we show...... under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent...... of the number of space-time dimensions and of the fluid arising from a gravitational dual, reveal the (electro)elastic character of (charged) black branes when considering extrinsic perturbations....

  16. Nonlinear stability of a brane wormhole

    Science.gov (United States)

    Akai, Yumi; Nakao, Ken-ichi

    2017-07-01

    We analytically study the nonlinear stability of a spherically symmetric wormhole supported by an infinitesimally thin brane of negative tension, which has been devised by Barcelo and Visser. We consider a situation in which a thin spherical shell composed of dust falls into an initially static wormhole; the dust shell plays the role of the nonlinear disturbance. The self-gravity of the falling dust shell is completely taken into account through Israel's formalism of the metric junction. When the dust shell goes through the wormhole, it necessarily collides with the brane supporting the wormhole. We assume the interaction between these shells is only gravity and show the condition under which the wormhole stably persists after the dust shell goes through it.

  17. Exotic branes in Double Field Theory

    Directory of Open Access Journals (Sweden)

    Musaev Edvard

    2016-01-01

    Full Text Available The non-geometric Q- and R-monopole are shown to be a particular case of the DFT-monopole solution. The notion of magnetic charge for the solutions is defined and shown to be equal to the magnetic charge of the NS5-brane solution. This is a talk presented by the author at the conference QUARKS’16 in St.-Petersburg.

  18. Chiral vortical effect from the compactified D4-branes with smeared D0-brane charge

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chao; Chen, Yidian [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China); Huang, Mei [Institute of High Energy Physics, Chinese Academy of Sciences,Beijing 100049 (China); University of Chinese Academy of Sciences,Beijing 100049 (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences,Beijing 100049 (China)

    2017-03-15

    By using the boundary derivative expansion formalism of fluid/gravity correspondence, we study the chiral vortical effect from the compactified D4-branes with smeared D0-brane charge. This background corresponds to a strongly coupled, nonconformal relativistic fluid with a conserved vector current. The presence of the chiral vortical effect is induced by the addition of a Chern-Simons term in the bulk action. Except that the non-dissipative anomalous viscous coefficient and the sound speed rely only on the chemical potential, most of the other thermal and hydrodynamical quantities of the first order depend both on the temperature and the chemical potential. According to our result, the way that the chiral vortical effect coefficient depends on the chemical potential seems irrelevant with whether the relativistic fluid is conformal or not. Stability analysis shows that this anomalous relativistic fluid is stable and the doping of the smeared D0-brane charge will slow down the sound speed.

  19. Cosmological Perturbations Across an S-brane

    CERN Document Server

    Brandenberger, Robert H; Partouche, Herve; Patil, Subodh P; Toumbas, N

    2014-01-01

    Space-filling S-branes can mediate a transition between a contracting and an expanding universe in the Einstein frame. Following up on previous work that uncovered such bouncing solutions in the context of weakly coupled thermal configurations of a certain class of type II superstrings, we set up here the formalism in which we can study the evolution of metric fluctuations across such an S-brane. Our work shows that the specific nature of the S-brane, which is sourced by non-trivial massless thermal string states and appears when the universe reaches a maximal critical temperature, allows for a scale invariant spectrum of curvature fluctuations to manifest at late times via a stringy realization of the matter bounce scenario. The finite energy density at the transition from contraction to expansion provides calculational control over the propagation of the curvature perturbations through the bounce, furnishing a working proof of concept that such a stringy universe can result in viable late time cosmology.

  20. Supersymmetric perturbations of the M5 brane

    Energy Technology Data Exchange (ETDEWEB)

    Niarchos, Vasilis [Crete Center for Theoretical Physics & Crete Center for Quantum Complexity and Nanotechnology,Department of Physics, University of Crete, 71303 (Greece)

    2014-05-07

    We study long-wavelength supersymmetric deformations of brane solutions in supergravity using an extension of previous ideas within the general scheme of the blackfold approach. As a concrete example, we consider long-wavelength perturbations of the planar M2-M5 bound state solution in eleven-dimensional supergravity. We propose a specific ansatz for the first order deformation of the supergravity fields and explore how this deformation perturbs the Killing spinor equations. We find that a special part of these equations gives a projection equation on the Killing spinors that has the same structure as the κ-symmetry condition of the abelian M5 brane theory. Requiring a match between supergravity and gauge theory implies a specific non-linear gauge-gravity map between the bosonic fields of the abelian M5 brane theory and the gravity-induced fluid-like degrees of freedom of the blackfold equations that control the perturbative gravity solution. This observation sheds new light on the SUGRA/DBI correspondence.

  1. EIA model documentation: World oil refining logistics demand model,``WORLD`` reference manual. Version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-11

    This manual is intended primarily for use as a reference by analysts applying the WORLD model to regional studies. It also provides overview information on WORLD features of potential interest to managers and analysts. Broadly, the manual covers WORLD model features in progressively increasing detail. Section 2 provides an overview of the WORLD model, how it has evolved, what its design goals are, what it produces, and where it can be taken with further enhancements. Section 3 reviews model management covering data sources, managing over-optimization, calibration and seasonality, check-points for case construction and common errors. Section 4 describes in detail the WORLD system, including: data and program systems in overview; details of mainframe and PC program control and files;model generation, size management, debugging and error analysis; use with different optimizers; and reporting and results analysis. Section 5 provides a detailed description of every WORLD model data table, covering model controls, case and technology data. Section 6 goes into the details of WORLD matrix structure. It provides an overview, describes how regional definitions are controlled and defines the naming conventions for-all model rows, columns, right-hand sides, and bounds. It also includes a discussion of the formulation of product blending and specifications in WORLD. Several Appendices supplement the main sections.

  2. Gauge-Higgs unification with brane kinetic terms

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, Alfredo [Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico)]. E-mail: fefo@ucol.mx; Diaz-Cruz, J. Lorenzo [Cuerpo Academico de Particulas, Campos y Relatividad, FCFM-BUAP, Puebla, Pue. 72570 (Mexico)]. E-mail: lorenzo.diaz@fcfm.buap.mx

    2006-02-16

    By identifying the Higgs field as an internal component of a higher-dimensional gauge field it is possible to solve the little hierarchy problem. The construction of a realistic model that incorporates such a gauge-Higgs unification is an important problem that demands attention. In fact, several attempts in this direction have already been put forward. In this Letter we single out one such attempt, a 6D SU(3) extended electroweak theory, where it is possible to obtain a Higgs mass prediction in accord with global fits. One shortcoming of the model is its prediction for the Weinberg angle, it is too large. We slightly modify the model by including brane kinetic terms in a way motivated by the orbifold action on the 6D fields. We show that in this way it is possible to obtain the correct Weinberg angle while keeping the desired results in the Higgs sector.

  3. One-loop adjoint masses for non-supersymmetric intersecting branes

    Energy Technology Data Exchange (ETDEWEB)

    Anastasopoulos, P. [Technische Univ., Vienna (Austria). 1. Inst. fuer Theoretische Physik; Antoniadis, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Benakli, K. [CNRS, UPMC Univ. Paris (France). Lab. de Physique Theorique et Haute Energies; Goodsell, M.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vichi, A. [Institute de Theorie des Phenomenes Physiques, EPFL, Lausanne (Switzerland)

    2011-05-15

    We consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by radiative corrections for the adjoint scalars on the brane world-volumes. In the open string channel, the string two-point function receives contributions only from the infrared and the ultraviolet limits. The latter is due to tree-level closed string uncanceled NS-NS tadpoles, which we explicitly reproduce from the effective Born-Infeld action. On the other hand, the infrared region reproduces the one-loop mediation of supersymmetry breaking in the effective gauge theory, via messengers and their Kaluza-Klein excitations. In the toroidal set-up considered here, it receives contributions only from N {approx} 4 and N {approx} 2 supersymmetric configurations, and thus always leads at leading order to a tachyonic direction, in agreement with effective field theory expectations. (orig.)

  4. One-loop adjoint masses for non-supersymmetric intersecting branes

    CERN Document Server

    Anastasopoulos, P; Benakli, K; Goodsell, M D; Vichi, A

    2011-01-01

    We consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by radiative corrections for the adjoint scalars on the brane world-volumes. In the open string channel, the string two-point function receives contributions only from the infrared and the ultraviolet limits. The latter is due to tree-level closed string uncanceled NS-NS tadpoles, which we explicitly reproduce from the effective Born-Infeld action. On the other hand, the infrared region reproduces the one-loop mediation of supersymmetry breaking in the effective gauge theory, via messengers and their Kaluza-Klein excitations. In the toroidal set-up considered here, it receives contributions only from broken N=4 and N=2 supersymmetric configurations, and thus always leads at leading order to a tachyonic direction, in agreement with effective field theory expectations.

  5. Supersymmetric bulk-brane coupling with odd gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, D.V.

    2006-08-15

    Supersymmetric bulk-brane coupling in Horava-Witten and Randall-Sundrum scenarios, when considered in the orbifold (''upstairs'') picture, enjoys similar features: a modified Bianchi identity and a modified supersymmetry transformation for the ''orthogonal'' part of the gauge field. Using a toy model with a 5D vector multiplet in the bulk (like in Mirabelli-Peskin model, but with an odd gauge field A{sub m}), we explain how these features arise from the superfield formulation. We also show that the corresponding construction in the boundary (''downstairs'') picture requires introduction of a special ''compensator'' (super)field. (orig.)

  6. Phase transitions in thick branes endorsed by entropic information

    Directory of Open Access Journals (Sweden)

    W.T. Cruz

    2017-09-01

    Full Text Available The so-called configurational entropy (CE framework has proved to be an efficient instrument to study nonlinear scalar field models featuring solutions with spatially-localised energy, since its proposal by Gleiser and Stamapoulos. Therefore, in this work, we apply this new physical quantity in order to investigate the properties of degenerate Bloch branes. We show that it is possible to construct a configurational entropy measure in functional space from the field configurations, where a complete set of exact solutions for the model studied displays both double and single-kink configurations. Our study shows a rich internal structure of the configurations, where we observe that the field configurations undergo a quick phase transition, which is endorsed by information entropy. Furthermore, the Bloch configurational entropy is employed to demonstrate a high organisational degree in the structure of the configurations of the system, stating that there is a best ordering for the solutions.

  7. Phase transitions in thick branes endorsed by entropic information

    Science.gov (United States)

    Cruz, W. T.; Dantas, D. M.; Correa, R. A. C.; Almeida, C. A. S.

    2017-09-01

    The so-called configurational entropy (CE) framework has proved to be an efficient instrument to study nonlinear scalar field models featuring solutions with spatially-localised energy, since its proposal by Gleiser and Stamapoulos. Therefore, in this work, we apply this new physical quantity in order to investigate the properties of degenerate Bloch branes. We show that it is possible to construct a configurational entropy measure in functional space from the field configurations, where a complete set of exact solutions for the model studied displays both double and single-kink configurations. Our study shows a rich internal structure of the configurations, where we observe that the field configurations undergo a quick phase transition, which is endorsed by information entropy. Furthermore, the Bloch configurational entropy is employed to demonstrate a high organisational degree in the structure of the configurations of the system, stating that there is a best ordering for the solutions.

  8. NMC and the Fine-Tuning Problem on the Brane

    Directory of Open Access Journals (Sweden)

    A. Safsafi

    2014-01-01

    Full Text Available We propose a new solution to the fine-tuning problem related to coupling constant λ of the potential. We study a quartic potential of the form λϕ4 in the framework of the Randall-Sundrum type II braneworld model in the presence of a Higgs field which interacts nonminimally with gravity via a possible interaction term of the form -(ξ/2ϕ2R. Using the conformal transformation techniques, the slow-roll parameters in high energy limit are reformulated in the case of a nonminimally coupled scalar field. We show that, for some value of a coupling parameter ξ and brane tension T, we can eliminate the fine-tuning problem. Finally, we present graphically the solutions of several values of the free parameters of the model.

  9. Hydro-elastic complementarity in black branes at large D

    Energy Technology Data Exchange (ETDEWEB)

    Emparan, Roberto [ICREA, Passeig Lluís Companys 23, E-08010 Barcelona (Spain); Departament de Física Fonamental, Institut de Ciències del Cosmos, Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain); Izumi, Keisuke; Luna, Raimon [Departament de Física Fonamental, Institut de Ciències del Cosmos, Universitat de Barcelona,Martí i Franquès 1, E-08028 Barcelona (Spain); Suzuki, Ryotaku [Department of Physics, Osaka City University, Osaka 558-8585 (Japan); Tanabe, Kentaro [Theory Center, Institute of Particles and Nuclear Studies, KEK,Tsukuba, Ibaraki, 305-0801 (Japan)

    2016-06-21

    We obtain the effective theory for the non-linear dynamics of black branes — both neutral and charged, in asymptotically flat or Anti-deSitter spacetimes — to leading order in the inverse-dimensional expansion. We find that black branes evolve as viscous fluids, but when they settle down they are more naturally viewed as solutions of an elastic soap-bubble theory. The two views are complementary: the same variable is regarded in one case as the energy density of the fluid, in the other as the deformation of the elastic membrane. The large-D theory captures finite-wavelength phenomena beyond the conventional reach of hydrodynamics. For asymptotically flat charged black branes (either Reissner-Nordstrom or p-brane-charged black branes) it yields the non-linear evolution of the Gregory-Laflamme instability at large D and its endpoint at stable non-uniform black branes. For Reissner-Nordstrom AdS black branes we find that sound perturbations do not propagate (have purely imaginary frequency) when their wavelength is below a certain charge-dependent value. We also study the polarization of black branes induced by an external electric field.

  10. Localization of abelian gauge fields on thick branes

    Energy Technology Data Exchange (ETDEWEB)

    Vaquera-Araujo, Carlos A. [Universidad de Colima, Facultad de Ciencias, CUICBAS, Colima (Mexico); Corradini, Olindo [Universidad Autonoma de Chiapas, Ciudad Universitaria, Facultad de Ciencias en Fisica y Matematicas, Tuxtla Gutierrez (Mexico); Universita di Modena e Reggio Emilia, Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Modena (Italy)

    2015-02-01

    In this work, we explore a mechanism for abelian gauge field localization on thick branes based on a five-dimensional Stueckelberg-like action. A normalizable zero mode is found through the identification of a suitable coupling function between the brane and the gauge field. The same mechanism is studied for the localization of the abelian Kalb-Ramond field. (orig.)

  11. Hydro-elastic complementarity in black branes at large D

    Science.gov (United States)

    Emparan, Roberto; Izumi, Keisuke; Luna, Raimon; Suzuki, Ryotaku; Tanabe, Kentaro

    2016-06-01

    We obtain the effective theory for the non-linear dynamics of black branes — both neutral and charged, in asymptotically flat or Anti-deSitter spacetimes — to leading order in the inverse-dimensional expansion. We find that black branes evolve as viscous fluids, but when they settle down they are more naturally viewed as solutions of an elastic soap-bubble theory. The two views are complementary: the same variable is regarded in one case as the energy density of the fluid, in the other as the deformation of the elastic membrane. The large- D theory captures finite-wavelength phenomena beyond the conventional reach of hydrodynamics. For asymptotically flat charged black branes (either Reissner-Nordstrom or p-brane-charged black branes) it yields the non-linear evolution of the Gregory-Laflamme instability at large D and its endpoint at stable non-uniform black branes. For Reissner-Nordstrom AdS black branes we find that sound perturbations do not propagate (have purely imaginary frequency) when their wavelength is below a certain charge-dependent value. We also study the polarization of black branes induced by an external electric field.

  12. The M5-brane and non-commutative loop space

    NARCIS (Netherlands)

    Bergshoeff, E.; Berman, D.; Schaar, J.P. van der; Sundell, P.

    2001-01-01

    We investigate, in a certain decoupling limit, the effect of having a constant C-field on the M-theory 5-brane using an open-membrane probe. We define an open-membrane metric for the 5-brane that remains non-degenerate in the limit. The canonical quantization of the open-membrane boundary leads to a

  13. Modeling Community to Heal an Injured World

    Science.gov (United States)

    Roper, Larry D.

    2012-01-01

    Our colleges and universities have the opportunity to play a role in transforming the tone of our current national discourse and model the core values of our democratic society as we prepare students to be civically responsible.

  14. Rapid prototype modeling in a multimodality world

    Science.gov (United States)

    Bidaut, Luc; Madewell, John; Yasko, Alan

    2006-03-01

    Introduction: Rapid prototype modeling (RPM) has been used in medicine principally for bones - that are easily extracted from CT data sets - for planning orthopaedic, plastic or maxillo-facial interventions, and/or for designing custom prostheses and implants. Based on newly available technology, highly valuable multimodality approaches can now be applied to RPM, particularly for complex musculo-skeletal (MSK) tumors where multimodality often transcends CT alone. Methods: CT data sets are acquired for primary evaluation of MSK tumors in parallel with other modalities (e.g., MR, PET, SPECT). In our approach, CT is first segmented to provide bony anatomy for RPM and all other data sets are then registered to the CT reference. Parametric information relevant to the tumor's characterization is then extracted from the multimodality space and merged with the CT anatomy to produce a hybrid RPM-ready model. This model - that also accommodates digital multimodality visualization - is then produced on the latest generation of 3D printers, which permits both shapes and colors. Results: Multimodality models of complex MSK tumors have been physically produced on modern RPM equipment. This new approach has been found to be a clear improvement over the previously disconnected physical RPM and digital multimodality visualization. Conclusions: New technical developments keep opening doors to sophisticated medical applications that can directly impact the quality of patient care. Although this early work still deals with bones as base models for RPM, its use to encompass soft tissues is already envisioned for future approaches.

  15. Left-right entanglement entropy of Dp-branes

    Energy Technology Data Exchange (ETDEWEB)

    Zayas, Leopoldo A. Pando [The Abdus Salam International Centre for Theoretical Physics,Strada Costiera 11, 34014 Trieste (Italy); Michigan Center for Theoretical Physics, Randall Laboratory of Physics,The University of Michigan,450 Church Street, Ann Arbor, MI 48109-1120 (United States); Quiroz, Norma [Departamento de Ciencias Exactas, Tecnología y Metodología,Centro Universitario del Sur, Universidad de Guadalajara,Enrique Arreola Silva 883, C.P. 49000, Cd. Guzmán, Jalisco (Mexico)

    2016-11-04

    We compute the left-right entanglement entropy for Dp-branes in string theory. We employ the CFT approach to string theory Dp-branes, in particular, its presentation as coherent states of the closed string sector. The entanglement entropy is computed as the von Neumann entropy for a density matrix resulting from integration over the left-moving degrees of freedom. We discuss various crucial ambiguities related to sums over spin structures and argue that different choices capture different physics; however, we advance a themodynamic argument that seems to favor a particular choice of replica. We also consider Dp branes on compact dimensions and verify that the effects of T-duality act covariantly on the Dp brane entanglement entropy. We find that generically the left-right entanglement entropy provides a suitable generalization of boundary entropy and of the D-brane tension.

  16. From p-branes to fluxbranes and back

    CERN Document Server

    Emparan, R; Emparan, Roberto; Gutperle, Michael

    2001-01-01

    In this note we study aspects of the interplay between fluxbranes and p-branes. We describe how a fluxbrane can be physically realized as a limit of a brane-antibrane configuration, in a manner similar to the way a uniform electric field appears in between the plates of a capacitor. We also study the evolution of a fluxbrane after nucleation of p-branes. We find that Kaluza-Klein fluxbranes do relax by forming brane-antibrane pairs or spherical branes, but we also find that for fluxtubes with dilaton coupling in a different range, the field strength does not relax, instead it becomes stronger after each nucleation bounce. We speculate on a possible runaway instability of such fluxtubes an an eventual breakdown of their classical description.

  17. Dielectric 5-Branes and Giant Gravitons in ABJM

    CERN Document Server

    Herrero, Mario; Picos, Marco

    2011-01-01

    We construct a supersymmetric NS5-brane wrapped on a twisted 5-sphere expanding in the $CP^3$ in $AdS_4\\times CP^3$, with D0-brane charge. This configuration provides a realization of the stringy exclusion principle in terms of giant D0-branes. In the maximal case the twisted 5-sphere reduces to a $CP^2$ and its energy can be accounted for both by a bound state of $k$ D4-branes wrapping the $CP^2$ and a bound state of $N$ D0-branes, a realization on the gravity side of the symmetry of Young diagrams with $N$ rows and $k$ columns. We discuss some generalizations of this configuration in M-theory carrying angular momentum, some of them with an interpretation as giant gravitons. We provide the microscopical description that allows to explore the region of finite 't Hooft coupling.

  18. Discrete Torsion, (Anti) de Sitter D4-Brane and Tunneling

    Science.gov (United States)

    Singh, Abhishek K.; Pandey, P. K.; Singh, Sunita; Kar, Supriya

    2014-06-01

    We obtain quantum geometries on a vacuum created pair of a (DDbar)3-brane, at a Big Bang singularity, by a local two form on a D4-brane. In fact our analysis is provoked by an established phenomenon leading to a pair creation by a gauge field at a black hole horizon by Stephen Hawking in 1975. Importantly, the five dimensional microscopic black holes are described by an effective non-perturbative curvature underlying a discrete torsion in a second order formalism. In the case for a non-propagating torsion, the effective curvature reduces to Riemannian, which in a low energy limit may describe Einstein vacuum in the formalism. In particular, our analysis suggests that a non-trivial space begin with a hot de Sitter brane-Universe underlying a nucleation of a vacuum pair of (DDbar)-instanton at a Big Bang. A pair of instanton nucleats a D-particle which in turn combines with an anti D-particle to describe a D-string and so on. The nucleation of a pair of higher dimensional pair of brane/anti-brane from a lower dimensional pair may be viewed via an expansion of the brane-Universe upon time. It is in conformity with the conjecture of a branes within a brane presumably in presence of the non-zero modes of two form. Interestingly, we perform a thermal analysis underlying various emergent quantum de Sitter vacua on a D4-brane and argue for the plausible tunneling geometries underlying a thermal equilibrium. It is argued that a de Sitter Schwarzschild undergoes quantum tunneling to an AdS-brane Schwarzschild via Nariai and de Sitter topological black hole.

  19. World Model in the European Gothic Novel and Regional Context

    Directory of Open Access Journals (Sweden)

    Anna Zvolimbovskaya

    2016-08-01

    Full Text Available The article deals with a specificity of the world model in the European Gothic novel and its regional context. The model of the world and the concept of a person are considered as the basic criteria of modern humanitarian knowledge. The object of study is presented by the novels of Charlotte Bronte “Jane Eyre”, Abraham «Bram» Stoker “Dracula” and others.

  20. A Real-World Network Modeling Project

    Science.gov (United States)

    2014-02-12

    topic of a Master’s thesis, and then developed into a full decision support system for missile defense (Brown et al., 2005). The project also provides...questions to help them proceed, and this could easily overwhelm the instructor. Accordingly, operations research faculty at NPS fluent in model...Optimization for Theater Ballistic Missile Defense. Operations Research, 53(5):745–763, 2005. G. G. Brown, W. M. Carlyle, R. Harney, E. Skroch, and R. K. Wood

  1. Scalar scattering from charged black holes on the brane

    Science.gov (United States)

    de Oliveira, Ednilton S.

    2018-03-01

    The differential scattering cross section of massless scalar fields localized on the 3-brane of charged static black holes in the ADD model is analyzed. While results valid over the entire range of the scattering angle can be obtained only via a numerical approach, analytical results can be obtained via the geodesic, Born and glory approximations. Comparison between numerical and analytical results leads to excellent agreement. The increase of the charge intensity has the consequence of increasing the width of the interference fringes in the scattering cross section. Its influence on the intensity of the scattered flux, however, depends on the dimensionality of the spacetime. Analyses for the special cases of uncharged and extremely charged black holes are included.

  2. Quantum phenomena modelled by interactions between many classical worlds

    Science.gov (United States)

    Wiseman, Howard; Hall, Michael; Deckert, Dirk-Andre

    2015-03-01

    We investigate how quantum theory can be understood as the continuum limit of a mechanical theory, in which there is a huge, but countable, number of classical ``worlds,'' and quantum effects arise solely from a universal interaction between these worlds, without reference to any wave function. Here a ``world'' means an entire universe with well-defined properties, determined by the classical configuration of its particles and fields. In our approach each world evolves deterministically; probabilities arise due to ignorance as to which world a given observer occupies; and we argue that in the limit of infinitely many worlds the wave function can be recovered (as a secondary object) from the motion of these worlds. We introduce a simple model of such a ``many interacting worlds'' approach and show that it can reproduce some generic quantum phenomena-such as Ehrenfest's theorem, wavepacket spreading, barrier tunneling and zero point energy-as a direct consequence of mutual repulsion between worlds. Finally, we perform numerical simulations using our approach. We demonstrate, first, that it can be used to calculate quantum ground states, and second, that it is capable of reproducing, at least qualitatively, the double-slit interference phenomenon.

  3. Quantum Phenomena Modeled by Interactions between Many Classical Worlds

    Science.gov (United States)

    Hall, Michael J. W.; Deckert, Dirk-André; Wiseman, Howard M.

    2014-10-01

    We investigate whether quantum theory can be understood as the continuum limit of a mechanical theory, in which there is a huge, but finite, number of classical "worlds," and quantum effects arise solely from a universal interaction between these worlds, without reference to any wave function. Here, a "world" means an entire universe with well-defined properties, determined by the classical configuration of its particles and fields. In our approach, each world evolves deterministically, probabilities arise due to ignorance as to which world a given observer occupies, and we argue that in the limit of infinitely many worlds the wave function can be recovered (as a secondary object) from the motion of these worlds. We introduce a simple model of such a "many interacting worlds" approach and show that it can reproduce some generic quantum phenomena—such as Ehrenfest's theorem, wave packet spreading, barrier tunneling, and zero-point energy—as a direct consequence of mutual repulsion between worlds. Finally, we perform numerical simulations using our approach. We demonstrate, first, that it can be used to calculate quantum ground states, and second, that it is capable of reproducing, at least qualitatively, the double-slit interference phenomenon.

  4. Holographic approach to deformations of NS5-brane distributions and exact CFTs

    CERN Document Server

    Fotopoulos, Angelos; Prezas, Nikolaos; Sfetsos, Konstadinos

    2008-01-01

    We consider general planar deformations of a circular distribution of NS5-branes. The near-horizon region of the latter admits, after a T-duality transformation, an exact conformal-field-theory description in terms of the coset model SU(2)/U(1) X SL(2,R)/U(1). We derive the exactly marginal operators corresponding to an infinitesimal planar deformation using the conjectured holography between the coset model and the little string theory that resides on the worldvolume of the NS5-branes. Subsequently, we perform a complementary analysis of the same deformations using the associated N=1 supersymmetric sigma model and verify the holographic correspondence. We explicitly demonstrate a precise match between the two approaches which rests upon a delicate interplay between exact conformal-field-theory operators and their semiclassical realizations in terms of target-space variables.

  5. Models of price development on world market for cocoa beans

    Directory of Open Access Journals (Sweden)

    Pavel Syrovátka

    2008-01-01

    Full Text Available This paper is focused on the modelling and simulating the development of the price of cocoa beans on the world market. The developed models were based on the dependence of the level of the world price of cocoa beans on the world stock to grindings ratio of the beans in the last crop year. The ICCO databases from 1960/1961 to 2005/2006 crop years were used for the estimation of the parameters in the investigated forms of the price model. The linear and logarithmic-linear categories of the price models were studied in this paper. Within the linear forms of the price models; the single linear construction and the linear construction with dummy time variable were specified and tested. Within the logarithmic-linear category of the price models; the error correction model and autoregressive model were examined. From the point of view of statistical verification and from the low value of deviation of the simulated world price of cocoa beans for the 2005/2006 period from the actual price level of price for this crop period, the logarithmic-linear form of model with the error correction achieved the best results. Acceptable results were also obtained by means of the modified price model with the error correction component. By using the logarithmic-linear form of error correction model, the world price of the cocoa beans for the crop period 2006/2007 will achieve the following value 1047 SDR · t−1.Under the modified error correction model, the level of the world price will be 1050 SDR · t−1.

  6. Working group report: Beyond the standard model

    Indian Academy of Sciences (India)

    Both the models cited above are multi-brane models with strong gravity localised on a brane-intersection. The meaning of localisation is that the graviton wave- function falls off exponentially outside the intersection. The standard model fields 'live' on a nearby brane, whose distance from the intersection sets the scale for the ...

  7. Squarks and sleptons between branes and bulk. Gaugino meditation and gravitino dark matter in an SO(10) orbifold GUT

    Energy Technology Data Exchange (ETDEWEB)

    Kersten, J.

    2006-05-15

    We study gaugino-mediated supersymmetry breaking in a six-dimensional SO(10) orbifold GUT model where quarks and leptons are mixtures of brane and bulk fields. The couplings of bulk matter fields to the supersymmetry breaking brane field have to be suppressed in order to avoid large FCNCs. We derive bounds on the soft supersymmetry breaking parameters and calculate the superparticle mass spectrum. If the gravitino is the LSP, the {tau}{sub 1} or the {nu}{sub {tau}}{sub L} turns out to be the NLSP, with characteristic signatures at future colliders and in cosmology. (Orig.)

  8. Supersymmetric branes on curved spaces and fluxes

    CERN Document Server

    Triendl, Hagen

    2015-01-01

    We discuss general supersymmetric brane configurations in flux backgrounds of string and M-theory and derive a necessary condition for the worldvolume theory to be supersymmetric on a given curved manifold. This condition resembles very much the conditions found from coupling a supersymmetric field theory to off-shell supergravity but can be derived in any dimension and for up to sixteen supercharges. Apart from the topological twist, all couplings appearing in the supersymmetry condition are linked to fluxes in the bulk. We explicitly derive the condition for D3-, M2- and M5-branes, in which case the results are also useful for constructing holographic duals to the corresponding field theories. In $N=1$ setups we compare the supersymmetry conditions to those that arise by coupling the field theory to off-shell supergravity. We find that the couplings of both old and new minimal supergravity are simultaneously realized, indicating that off-shell supergravity should be coupled via the S-multiplet of 16/16 supe...

  9. Constraining the cosmology of the phantom brane using distance measures

    Science.gov (United States)

    Alam, Ujjaini; Bag, Satadru; Sahni, Varun

    2017-01-01

    The phantom brane has several important distinctive features: (i) Its equation of state is phantomlike, but there is no future "big rip" singularity, and (ii) the effective cosmological constant on the brane is dynamically screened, because of which the expansion rate is smaller than that in Λ CDM at high redshifts. In this paper, we constrain the Phantom braneworld using distance measures such as type-Ia supernovae (SNeIa), baryon acoustic oscillations (BAO), and the compressed cosmic microwave background (CMB) data. We find that the simplest braneworld models provide a good fit to the data. For instance, BAO +SNeIa data can be accommodated by the braneworld for a large region in parameter space 0 ≤Ωℓ≲0.3 at 1 σ . The Hubble parameter can be as high as H0≲78 km s-1 Mpc-1 , and the effective equation of state at present can show phantomlike behavior with w0≲-1.2 at 1 σ . We note a correlation between H0 and w0, with higher values of H0 leading to a lower, and more phantomlike, value of w0. Inclusion of CMB data provides tighter constraints Ωℓ≲0.1 . (Here Ωℓ encodes the ratio of the five- and four-dimensional Planck mass.) The Hubble parameter in this case is more tightly constrained to H0≲71 km s-1 Mpc-1 , and the effective equation of state to w0≲-1.1 . Interestingly, we find that the Universe is allowed to be closed or open, with -0.5 ≲Ωκ≲0.5 , even on including the compressed CMB data. There appears to be some tension in the low and high-z BAO data which may either be resolved by future data, or act as a pointer to interesting new cosmology.

  10. On the 3-form formulation of axion potentials from D-brane instantons

    Energy Technology Data Exchange (ETDEWEB)

    García-Valdecasas, Eduardo [Instituto de Física Teórica UAM-CSIC,C/Nicolás Cabrera 13-15, Campus de Cantoblanco, 28049 Madrid (Spain); Departamento de Física Teórica, Universidad Autónoma de Madrid,Campus de Cantoblanco, 28049 Madrid (Spain); Uranga, Angel [Instituto de Física Teórica UAM-CSIC,C/Nicolás Cabrera 13-15, Campus de Cantoblanco, 28049 Madrid (Spain)

    2017-02-16

    The study of axion models and quantum corrections to their potential has experienced great progress by phrasing the axion potential in terms of a 3-form field eating up the 2-form field dual to the axion. Such reformulation of the axion potential has been described for axion monodromy models and for axion potentials from non-perturbative gauge dynamics. In this paper we propose a 3-form description of the axion potentials from non-gauge D-brane instantons. Interestingly, the required 3-form field does not arise in the underlying geometry, but rather shows up in the KK compactification in the generalized geometry obtained when the backreaction of the D-brane instanton is taken into account.

  11. Simulation and similarity using models to understand the world

    CERN Document Server

    Weisberg, Michael

    2013-01-01

    In the 1950s, John Reber convinced many Californians that the best way to solve the state's water shortage problem was to dam up the San Francisco Bay. Against massive political pressure, Reber's opponents persuaded lawmakers that doing so would lead to disaster. They did this not by empirical measurement alone, but also through the construction of a model. Simulation and Similarity explains why this was a good strategy while simultaneously providing an account of modeling and idealization in modern scientific practice. Michael Weisberg focuses on concrete, mathematical, and computational models in his consideration of the nature of models, the practice of modeling, and nature of the relationship between models and real-world phenomena. In addition to a careful analysis of physical, computational, and mathematical models, Simulation and Similarity offers a novel account of the model/world relationship. Breaking with the dominant tradition, which favors the analysis of this relation through logical notions suc...

  12. The joint US/UK 1990 epoch world magnetic model

    Science.gov (United States)

    Quinn, John M.; Coleman, Rachel J.; Peck, Michael R.; Lauber, Stephen E.

    1991-01-01

    A detailed summary of the data used, analyses performed, modeling techniques employed, and results obtained in the course of the 1990 Epoch World Magnetic Modeling effort are given. Also, use and limitations of the GEOMAG algorithm are presented. Charts and tables related to the 1990 World Magnetic Model (WMM-90) for the Earth's main field and secular variation in Mercator and polar stereographic projections are presented along with useful tables of several magnetic field components and their secular variation on a 5-degree worldwide grid.

  13. Refined toric branes, surface operators and factorization of generalized Macdonald polynomials

    Science.gov (United States)

    Zenkevich, Yegor

    2017-09-01

    We find new universal factorization identities for generalized Macdonald polynomials on the topological locus. We prove the identities (which include all previously known forumlas of this kind) using factorization identities for matrix model averages, which are themselves consequences of Ding-Iohara-Miki constraints. Factorized expressions for generalized Macdonald polynomials are identified with refined topological string amplitudes containing a toric brane on an intermediate preferred leg, surface operators in gauge theory and certain degenerate CFT vertex operators.

  14. Gauss-Bonnet Braneworld Cosmology with Modified Induced Gravity on the Brane

    Directory of Open Access Journals (Sweden)

    Kourosh Nozari

    2013-01-01

    Full Text Available We analyze the background cosmology for an extension of the DGP gravity with Gauss-Bonnet term in the bulk and f(R gravity on the brane. We investigate implications of this setup on the late-time cosmic history. Within a dynamical system approach, we study cosmological dynamics of this setup focusing on the role played by curvature effects. Finally, we constrain the parameters of the model by confrontation with recent observational data.

  15. Gauge theories from D7-branes over vanishing 4-cycles

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Sebastian; /Santa Barbara, KITP; Torroba, Gonzalo; /SLAC /Stanford U., Phys. Dept.

    2010-12-16

    We study quiver gauge theories on D7-branes wrapped over vanishing holomorphic 4-cycles. We investigate how to incorporate O7-planes and/or flavor D7-branes, which are necessary to cancel anomalies. These theories are chiral, preserve four supercharges and exhibit very rich infrared dynamics. Geometric transitions and duality in the presence of O-planes are analyzed. We study the Higgs branch of these quiver theories, showing the emergence of fuzzy internal dimensions. This branch is related to noncommutative instantons on the divisor wrapped by the seven-branes. Our results have a natural application to the recently introduced F(uzz) limit of F-theory.

  16. Anti-D3 branes and moduli in non-linear supergravity

    Science.gov (United States)

    Garcia del Moral, Maria P.; Parameswaran, Susha; Quiroz, Norma; Zavala, Ivonne

    2017-10-01

    Anti-D3 branes and non-perturbative effects in flux compactifications spontaneously break supersymmetry and stabilise moduli in a metastable de Sitter vacua. The low energy 4D effective field theory description for such models would be a supergravity theory with non-linearly realised supersymmetry. Guided by string theory modular symmetry, we compute this non-linear supergravity theory, including dependence on all bulk moduli. Using either a constrained chiral superfield or a constrained vector field, the uplifting contribution to the scalar potential from the anti-D3 brane can be parameterised either as an F-term or Fayet-Iliopoulos D-term. Using again the modular symmetry, we show that 4D non-linear supergravities that descend from string theory have an enhanced protection from quantum corrections by non-renormalisation theorems. The superpotential giving rise to metastable de Sitter vacua is robust against perturbative string-loop and α' corrections.

  17. Systematics of multi-field effects at the end of warped brane inflation

    CERN Document Server

    Chen, Heng-Yu; Shiu, Gary

    2008-01-01

    We investigate in the context of brane inflation the possibility of additional light scalar fields generating significant power spectrum and non-Gaussianities at the end of inflation affecting the CMB scale observations. We consider the specific mechanism outlined by Lyth and describe the necessary criteria for it to be potentially important in a warped throat. We also discuss different mechanisms for uplifting the vacuum energy which can lead to different dominant contributions of the inflaton potential near the end of inflation. We then apply such criteria to one of the most detailed brane inflation models to date, and show that inflation can persist towards the tip of the throat, however for the specific stable inflationary trajectory, the light residual isometry direction becomes degenerate. We also estimate the effects for other inflationary trajectories with non-degenerate residual isometries.

  18. Non-BPS D-brane Solutions in Six Dimensional Orbifolds

    CERN Document Server

    Lozano, Y

    2000-01-01

    Starting with the non-BPS D0-brane solution of IIB/$(-1)^{F_L}I_4$ constructed recently by Eyras and Panda we construct via T-duality the non-BPS D2-brane and D1-brane solutions of IIB/$(-1)^{F_L}I_4$ and IIA/$(-1)^{F_L}I_4$ predicted by Sen. The D2-brane couples magnetically to the vector field of the NS5B-brane living in the twisted sector of the Type IIB orbifold, whereas the D1-brane couples (electrically and magnetically) to the self-dual 2-form potential of the NS5A-brane that is present in the twisted sector of the Type IIA orbifold construction. Finally we discuss the eleven dimensional interpretation of these branes as originating from a non-BPS M1-brane solution of M-theory orientifolded by $\\Omega_\\rho I_5$.

  19. Non-Singular Solutions for S-Branes

    Energy Technology Data Exchange (ETDEWEB)

    Jones, G.

    2004-03-03

    Exact, non-singular, time-dependent solutions of Maxwell-Einstein gravity with and without dilatons are constructed by double Wick rotating a variety of static, axisymmetric solutions. This procedure transforms arrays of charged or neutral black holes into s-brane (spacelike brane) solutions, i.e. extended, short-lived spacelike defects. Along the way, new static solutions corresponding to arrays of alternating-charge Reissner-Nordstrom black holes, as well as their dilatomic generalizations, are found. their double Wick rotation yields s-brane solutions which are periodic in imaginary time and potential large-N duals for the creation/decay of unstable D-branes in string theory.

  20. Holography, probe branes and isoperimetric inequalities

    Directory of Open Access Journals (Sweden)

    Frank Ferrari

    2015-07-01

    Full Text Available In many instances of holographic correspondences between a d-dimensional boundary theory and a (d+1-dimensional bulk, a direct argument in the boundary theory implies that there must exist a simple and precise relation between the Euclidean on-shell action of a (d−1-brane probing the bulk geometry and the Euclidean gravitational bulk action. This relation is crucial for the consistency of holography, yet it is non-trivial from the bulk perspective. In particular, we show that it relies on a nice isoperimetric inequality that must be satisfied in a large class of Poincaré–Einstein spaces. Remarkably, this inequality follows from theorems by Lee and Wang.

  1. On Least Action D-Branes

    CERN Document Server

    Elitzur, Shmuel; Sarkisian, G; Elitzur, Shmuel; Rabinovici, Eliezer; Sarkissian, Gor

    1999-01-01

    We discuss the effect of relevant boundary terms on the nature of branes. This is done for toroidal and orbifold compactifications of the bosonic string. Using the relative minimalization of the boundary entropy as a guiding principle, we uncover the more stable boundary conditions at different regions of moduli space. In some cases, Neumann boundary conditions dominate for small radii while Dirichlet boundary conditions dominate for large radii. The c=1 and c=2 moduli spaces are studied in some detail. The antisymmetric background field B is found to have a more limited role in the case of Dirichlet boundary conditions. This is due to some topological considerations. The results are subjected to T-duality tests and the special role of the points in moduli space fixed under T-duality is explained from least-action considerations.

  2. Interaction of higher-dimensional rotating black holes with branes

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Valeri P [Theoretical Physics Institute, Department of Physics, University of Alberta, Edmonton T6G 2J1 (Canada); Fursaev, Dmitri V [Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, 141 980 Dubna (Russian Federation); Stojkovic, Dejan [MCTP, Department of Physics, University of Michigan, Ann Arbor, MI (United States)

    2004-07-21

    We study interaction of rotating higher-dimensional black holes with a brane in spacetimes with large extra dimensions. We demonstrate that in a general case a rotating black hole attached to a brane can lose bulk components of its angular momenta. A stationary black hole can have only those components of the angular momenta which are connected with Killing vectors generating transformations preserving a position of the brane. In a final stationary state the null Killing vector generating the black hole horizon is tangent to the brane. We discuss first the interaction of a cosmic string and a domain wall with the 4D Kerr black hole. We then prove the general result for slowly rotating higher-dimensional black holes interacting with branes. The characteristic time when a rotating black hole with gravitational radius r{sub 0} reaches this final stationary state is T {approx} r{sup p-1}{sub 0}/(G{sigma}), where G is the higher-dimensional gravitational coupling constant, {sigma} is the brane tension and p is the number of extra dimensions.

  3. Step-indexed Kripke models over recursive worlds

    DEFF Research Database (Denmark)

    Birkedal, Lars; Reus, Bernhard; Schwinghammer, Jan

    2011-01-01

    worlds that are recursively defined in a category of metric spaces. In this paper, we broaden the scope of this technique from the original domain-theoretic setting to an elementary, operational one based on step indexing. The resulting method is widely applicable and leads to simple, succinct models...

  4. Fine-tuning with brane-localized flux in 6D supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Niedermann, Florian; Schneider, Robert [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität,Theresienstraße 37, 80333 Munich (Germany); Excellence Cluster Universe,Boltzmannstraße 2, 85748 Garching (Germany)

    2016-02-03

    There are claims in the literature that the cosmological constant problem could be solved in a braneworld model with two large (micron-sized) supersymmetric extra dimensions. The mechanism relies on two basic ingredients: first, the cosmological constant only curves the compact bulk geometry into a rugby shape while the 4D curvature stays flat. Second, a brane-localized flux term is introduced in order to circumvent Weinberg’s fine-tuning argument, which otherwise enters here through a backdoor via the flux quantization condition. In this paper, we show that the latter mechanism does not work in the way it was designed: the only localized flux coupling that guarantees a flat on-brane geometry is one which preserves the scale invariance of the bulk theory. Consequently, Weinberg’s argument applies, making a fine-tuning necessary again. The only remaining window of opportunity lies within scale invariance breaking brane couplings, for which the tuning could be avoided. Whether the corresponding 4D curvature could be kept under control and in agreement with the observed value will be answered in our companion paper http://arxiv.org/abs/1512.03800.

  5. Fine-tuning with brane-localized flux in 6D supergravity

    Science.gov (United States)

    Niedermann, Florian; Schneider, Robert

    2016-02-01

    There are claims in the literature that the cosmological constant problem could be solved in a braneworld model with two large (micron-sized) supersymmetric extra dimensions. The mechanism relies on two basic ingredients: first, the cosmological constant only curves the compact bulk geometry into a rugby shape while the 4D curvature stays flat. Second, a brane-localized flux term is introduced in order to circumvent Weinberg's fine-tuning argument, which otherwise enters here through a backdoor via the flux quantization condition. In this paper, we show that the latter mechanism does not work in the way it was designed: the only localized flux coupling that guarantees a flat on-brane geometry is one which preserves the scale invariance of the bulk theory. Consequently, Weinberg's argument applies, making a fine-tuning necessary again. The only remaining window of opportunity lies within scale invariance breaking brane couplings, for which the tuning could be avoided. Whether the corresponding 4D curvature could be kept under control and in agreement with the observed value will be answered in our companion paper [1].

  6. B-branes and supersymmetric quivers in 2d arXiv

    CERN Document Server

    Closset, Cyril; Sharpe, Eric

    We study 2d $\\mathcal{N}=(0,2)$ supersymmetric quiver gauge theories that describe the low-energy dynamics of D1-branes at Calabi-Yau fourfold (CY$_4$) singularities. On general grounds, the holomorphic sector of these theories---matter content and (classical) superpotential interactions---should be fully captured by the topological $B$-model on the CY$_4$. By studying a number of examples, we confirm this expectation and flesh out the dictionary between B-brane category and supersymmetric quiver: the matter content of the supersymmetric quiver is encoded in morphisms between B-branes (that is, Ext groups of coherent sheaves), while the superpotential interactions are encoded in the $A_\\infty$ algebra satisfied by the morphisms. This provides us with a derivation of the supersymmetric quiver directly from the CY$_4$ geometry. We also suggest a relation between triality of $\\mathcal{N}=(0,2)$ gauge theories and certain mutations of exceptional collections of sheaves. 0d $\\mathcal{N}=1$ supersymmetric quivers, ...

  7. Evolving Four Part Harmony Using a Multiple Worlds Model

    DEFF Research Database (Denmark)

    Scirea, Marco; Brown, Joseph Alexander

    2015-01-01

    This application of the Multiple Worlds Model examines a collaborative fitness model for generating four part harmonies. In this model we have multiple populations and the fitness of the individuals is based on the ability of a member from each population to work with the members of other...... populations. We present the result of two experiments: the generation of compositions, given a static voice line, both in a constrained and unconstrained harmonic framework. The remaining three voices are evolved using this collaborative fitness function, which looks for a number of classical composition...

  8. A small-world network model of facial emotion recognition.

    Science.gov (United States)

    Takehara, Takuma; Ochiai, Fumio; Suzuki, Naoto

    2016-01-01

    Various models have been proposed to increase understanding of the cognitive basis of facial emotions. Despite those efforts, interactions between facial emotions have received minimal attention. If collective behaviours relating to each facial emotion in the comprehensive cognitive system could be assumed, specific facial emotion relationship patterns might emerge. In this study, we demonstrate that the frameworks of complex networks can effectively capture those patterns. We generate 81 facial emotion images (6 prototypes and 75 morphs) and then ask participants to rate degrees of similarity in 3240 facial emotion pairs in a paired comparison task. A facial emotion network constructed on the basis of similarity clearly forms a small-world network, which features an extremely short average network distance and close connectivity. Further, even if two facial emotions have opposing valences, they are connected within only two steps. In addition, we show that intermediary morphs are crucial for maintaining full network integration, whereas prototypes are not at all important. These results suggest the existence of collective behaviours in the cognitive systems of facial emotions and also describe why people can efficiently recognize facial emotions in terms of information transmission and propagation. For comparison, we construct three simulated networks--one based on the categorical model, one based on the dimensional model, and one random network. The results reveal that small-world connectivity in facial emotion networks is apparently different from those networks, suggesting that a small-world network is the most suitable model for capturing the cognitive basis of facial emotions.

  9. Standard Models from Heterotic M-theory

    CERN Document Server

    Donagi, R Y; Pantev, T; Waldram, D; Donagi, Ron; Ovrut, Burt A.; Pantev, Tony; Waldram, Daniel

    1999-01-01

    We present a class of N=1 supersymmetric models of particle physics, derived directly from heterotic M-theory, that contain three families of chiral quarks and leptons coupled to the gauge group $SU(3)_C\\times SU(2)_{L}\\times U(1)_{Y}$. These models are a fundamental form of ``brane-world'' theories, with an observable and hidden sector each confined, after compactification on a Calabi-Yau threefold, to a BPS three-brane separated by a five dimensional bulk space with size of the order of the intermediate scale. The requirement of three families, coupled to the fundamental conditions of anomaly freedom and supersymmetry, constrains these models to contain additional five-branes wrapped around holomorphic curves in the Calabi-Yau threefold. These five-branes ``live'' in the bulk space and represent new, non-perturbative aspects of these particle physics vacua. We discuss, in detail, the relevant mathematical structure of a class of torus-fibered Calabi-Yau threefolds with non-trivial first homotopy groups and ...

  10. Data Modeling for Mobile Services in the Real World

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Pedersen, Torben Bach; Speicys, L.

    2003-01-01

    . In contrast, this paper describes holistic concepts and techniques for mobile data modeling that are readily applicable in practice. Focus is on services to be delivered to mobile users, such as route guidance, point-of-interest search, road pricing, parking payment, traffic monitoring, etc. While geo......Research contributions on data modeling, data structures, query processing, and indexing for mobile services may have an impact in the longer term, but each contribution typically offers an isolated solution to one small part of the practical problem of delivering mobile services in the real world...

  11. Thermodynamics of spinning branes and their dual field theories

    DEFF Research Database (Denmark)

    Harmark, Troels; Obers, N. A.

    2000-01-01

    limits are remarkably close and (ii) The tree-level R^4 corrections to the spinning D3-brane generate a decrease in the free energy at strong coupling towards the weak coupling result. We also comment on the generalization to spinning brane bound states and their thermodynamics, which are relevant......-symmetry. The thermodynamics is used to provide two pieces of evidence in favor of a smooth interpolation function between the free energy at weak and strong coupling of the field theory. (i) A computation of the boundaries of stability shows that for the D2, D3, D4, M2 and M5-branes the critical values of Omega/T in the two......We discuss general spinning p-branes of string and M-theory and use their thermodynamics along with the correspondence between near-horizon brane solutions and field theories with 16 supercharges to describe the thermodynamic behavior of these theories in the presence of voltages under the R...

  12. Aspects of string theory compactifications. D-brane statistics and generalised geometry

    Energy Technology Data Exchange (ETDEWEB)

    Gmeiner, F.

    2006-05-26

    In this thesis we investigate two different aspects of string theory compactifications. The first part deals with the issue of the huge amount of possible string vacua, known as the landscape. Concretely we investigate a specific well defined subset of type II orientifold compactifications. We develop the necessary tools to construct a very large set of consistent models and investigate their gauge sector on a statistical basis. In particular we analyse the frequency distributions of gauge groups and the possible amount of chiral matter for compactifications to six and four dimensions. In the phenomenologically relevant case of four-dimensional compactifications, special attention is paid to solutions with gauge groups that include those of the standard model, as well as Pati-Salam, SU(5) and flipped SU(5) models. Additionally we investigate the frequency distribution of coupling constants and correlations between the observables in the gauge sector. These results are compared with a recent study of Gepner models. Moreover, we elaborate on questions concerning the finiteness of the number of solutions and the computational complexity of the algorithm. In the second part of this thesis we consider a new mathematical framework, called generalised geometry, to describe the six-manifolds used in string theory compactifications. In particular, the formulation of T-duality and mirror symmetry for nonlinear topological sigma models is investigated. Therefore we provide a reformulation and extension of the known topological A- and B-models to the generalised framework. The action of mirror symmetry on topological D-branes in this setup is presented and the transformation of the boundary conditions is analysed. To extend the considerations to D-branes in type II string theory, we introduce the notion of generalised calibrations. We show that the known calibration conditions of supersymmetric branes in type IIA and IIB can be obtained as special cases. Finally we investigate

  13. A World Trade Model Based on Comparative Advantage with m Regions, n Goods, and k Factors.

    OpenAIRE

    Faye Duchin

    2003-01-01

    This paper describes the World Trade Model, a linear program that determines world prices, scarcity rents, and international trade flows based on comparative advantage in a world economy with m regions, n goods, and k factors. Major properties of the model are demonstrated, including the sources of the gains from trade for the world as a whole and for individual regions. Preliminary empirical results are reported for a 10-region, 8-good, 3-factor model of the world economy. The new model gene...

  14. Brane to bulk supersymmetry breaking and radion force at micron distances

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, I.; Benakli, K. E-mail: karim.benakli@cern.ch; Laugier, A.; Maillard, T

    2003-07-07

    We study mediation of supersymmetry breaking in the bulk, in models with primordial supersymmetry breaking on D-branes at the string scale, in the TeV region. We compute the gravitino and scalar masses up to one-loop level, as well as the radion coupling to matter. We find that the latter mediates a model independent force at submillimeter distances that can be tested in micro-gravity experiments for any dimensionality of the bulk. In the case of two large dimensions, our type I string framework provides an example which allows to stabilize the radion potential and determine the desired hierarchy between the string and Planck scales.

  15. Closed timelike curves in asymmetrically warped brane universes

    Science.gov (United States)

    Päs, Heinrich; Pakvasa, Sandip; Dent, James; Weiler, Thomas J.

    2009-08-01

    In asymmetrically-warped spacetimes different warp factors are assigned to space and to time. We discuss causality properties of these warped brane universes and argue that scenarios with two extra dimensions may allow for timelike curves which can be closed via paths in the extra-dimensional bulk. In particular, necessary and sufficient conditions on the metric for the existence of closed timelike curves are presented. We find a six-dimensional warped metric which satisfies the CTC conditions, and where the null, weak and dominant energy conditions are satisfied on the brane (although only the former remains satisfied in the bulk). Such scenarios are interesting, since they open the possibility of experimentally testing the chronology protection conjecture by manipulating on our brane initial conditions of gravitons or hypothetical gauge-singlet fermions (“sterile neutrinos”) which then propagate in the extra dimensions.

  16. Dynamic SU(2) structure from seven-branes

    Energy Technology Data Exchange (ETDEWEB)

    Heidenreich, Ben; McAllister, Liam; /Cornell U., Phys. Dept.; Torroba, Gonzalo; /SLAC /Stanford U., Phys. Dept.

    2010-12-16

    We obtain a family of supersymmetric solutions of type IIB supergravity with dynamic SU(2) structure, which describe the local geometry near a stack of four D7-branes and one O7-plane wrapping a rigid four-cycle. The deformation to a generalized complex geometry is interpreted as a consequence of nonperturbative effects in the seven-brane gauge theory. We formulate the problem for seven-branes wrapping the base of an appropriate del Pezzo cone, and in the near-stack limit in which the four-cycle is flat, we obtain an exact solution in closed form. Our solutions serve to characterize the local geometry of nonperturbatively-stabilized flux compactifications.

  17. Brane bounce from logarithmic entropic corrections in the bulk

    Science.gov (United States)

    Addazi, Andrea

    2017-10-01

    We calculate new corrections to the braneworld dynamics, lying in a 5D Schwarzschild-de Sitter black hole, generalizing the result of Nojiri, Odintsov and Ogushi (NOO). The NOO entropy effect is based on the logarithmic correction to the bulk entropy firstly calculated by Mukherji and Pal. We calculate higher order contributions to the brane worldsheet. The extra terms obtained lead to interesting implications in brane cosmology. In particular, new entropic terms rapidly disappear in the late Universe while exploding in the very early Universe. In particular, we show that they may trigger a cosmological bounce in the very early Universe. On the other hand, they contribute to the cosmological expansion in the late Universe. We also discuss a scenario in which the BLK anisotropies are washed out, toward a new ekpyrotic brane cosmology.

  18. Branes for Higgs phases and exact conformal field theories

    CERN Document Server

    Sfetsos, K

    1999-01-01

    We consider multicenter supergravity solutions corresponding to Higgs phases of supersymmetric Yang-Mills theories with Z_N symmetric vacuua. In certain energy regimes, we find a description in terms of a generalized wormhole solution that corresponds to the SL(2,R)/U(1) \\times SU(2)/U(1) exact conformal field theory. We show that U-dualities map these backgrounds to purely gravitational ones and comment on the relation to the black holes arising from intersecting D1 and D5 branes. We also discuss supersymmetric properties of the various solutions and the relation to 2-dim solitons, on flat space, of the reduced axion-dilaton-gravity equations. Finally, we address the problem of understanding other supergravity solutions from the multicenter ones. As prototype examples we use rotating D3 branes and NS5 and D5 branes associated to non-Abelian duals of 4-dim hyper-Kahler metrics with SO(3) isometry.

  19. Five-dimensional Nernst branes from special geometry

    Energy Technology Data Exchange (ETDEWEB)

    Dempster, P.; Errington, D. [Department of Mathematical Sciences, University of LiverpoolPeach Street, Liverpool L69 7ZL (United Kingdom); Gutowski, J. [Department of Mathematics, University of Surrey,Guildford, GU2 7XH (United Kingdom); Mohaupt, T. [Department of Mathematical Sciences, University of LiverpoolPeach Street, Liverpool L69 7ZL (United Kingdom)

    2016-11-21

    We construct Nernst brane solutions, that is black branes with zero entropy density in the extremal limit, of FI-gauged minimal five-dimensional supergravity coupled to an arbitrary number of vector multiplets. While the scalars take specific constant values and dynamically determine the value of the cosmological constant in terms of the FI-parameters, the metric takes the form of a boosted AdS Schwarzschild black brane. This metric can be brought to the Carter-Novotný-Horský form that has previously been observed to occur in certain limits of boosted D3-branes. By dimensional reduction to four dimensions we recover the four-dimensional Nernst branes of arXiv:1501.07863 and show how the five-dimensional lift resolves all their UV singularities. The dynamics of the compactification circle, which expands both in the UV and in the IR, plays a crucial role. At asymptotic infinity, the curvature singularity of the four-dimensional metric and the run-away behaviour of the four-dimensional scalar combine in such a way that the lifted solution becomes asymptotic to AdS{sub 5}. Moreover, the existence of a finite chemical potential in four dimensions is related to fact that the compactification circle has a finite minimal value. While it is not clear immediately how to embed our solutions into string theory, we argue that the same type of dictionary as proposed for boosted D3-branes should apply, although with a lower amount of supersymmetry.

  20. Multiplicative Attribute Graph Model of Real-World Networks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myunghwan [Stanford Univ., CA (United States); Leskovec, Jure [Stanford Univ., CA (United States)

    2010-10-20

    Large scale real-world network data, such as social networks, Internet andWeb graphs, is ubiquitous in a variety of scientific domains. The study of such social and information networks commonly finds patterns and explain their emergence through tractable models. In most networks, especially in social networks, nodes also have a rich set of attributes (e.g., age, gender) associatedwith them. However, most of the existing network models focus only on modeling the network structure while ignoring the features of nodes in the network. Here we present a class of network models that we refer to as the Multiplicative Attribute Graphs (MAG), which naturally captures the interactions between the network structure and node attributes. We consider a model where each node has a vector of categorical features associated with it. The probability of an edge between a pair of nodes then depends on the product of individual attributeattribute similarities. The model yields itself to mathematical analysis as well as fit to real data. We derive thresholds for the connectivity, the emergence of the giant connected component, and show that the model gives rise to graphs with a constant diameter. Moreover, we analyze the degree distribution to show that the model can produce networks with either lognormal or power-law degree distribution depending on certain conditions.

  1. Mathematics in Nature Modeling Patterns in the Natural World

    CERN Document Server

    Adam, John A

    2011-01-01

    From rainbows, river meanders, and shadows to spider webs, honeycombs, and the markings on animal coats, the visible world is full of patterns that can be described mathematically. Examining such readily observable phenomena, this book introduces readers to the beauty of nature as revealed by mathematics and the beauty of mathematics as revealed in nature.Generously illustrated, written in an informal style, and replete with examples from everyday life, Mathematics in Nature is an excellent and undaunting introduction to the ideas and methods of mathematical modeling. It illustrates how mathem

  2. A Markovian model of evolving world input-output network.

    Science.gov (United States)

    Moosavi, Vahid; Isacchini, Giulio

    2017-01-01

    The initial theoretical connections between Leontief input-output models and Markov chains were established back in 1950s. However, considering the wide variety of mathematical properties of Markov chains, so far there has not been a full investigation of evolving world economic networks with Markov chain formalism. In this work, using the recently available world input-output database, we investigated the evolution of the world economic network from 1995 to 2011 through analysis of a time series of finite Markov chains. We assessed different aspects of this evolving system via different known properties of the Markov chains such as mixing time, Kemeny constant, steady state probabilities and perturbation analysis of the transition matrices. First, we showed how the time series of mixing times and Kemeny constants could be used as an aggregate index of globalization. Next, we focused on the steady state probabilities as a measure of structural power of the economies that are comparable to GDP shares of economies as the traditional index of economies welfare. Further, we introduced two measures of systemic risk, called systemic influence and systemic fragility, where the former is the ratio of number of influenced nodes to the total number of nodes, caused by a shock in the activity of a node, and the latter is based on the number of times a specific economic node is affected by a shock in the activity of any of the other nodes. Finally, focusing on Kemeny constant as a global indicator of monetary flow across the network, we showed that there is a paradoxical effect of a change in activity levels of economic nodes on the overall flow of the world economic network. While the economic slowdown of the majority of nodes with high structural power results to a slower average monetary flow over the network, there are some nodes, where their slowdowns improve the overall quality of the network in terms of connectivity and the average flow of the money.

  3. In quest of a new world order: a world organization modeled after the International Atomic Energy Agency (IAEA)

    Energy Technology Data Exchange (ETDEWEB)

    Mehring, C.E.

    1979-01-01

    The problem of this study was to find or develop an appropriate model for a world order which would maintain a balance between it and the various national governments. Underpinning the problem were the assumptions that the world has, historically, moved in the direction of ever larger units of government and of international cooperation, that nationalism and patriotism have always represented major obstacles to this movement, and that world order is necessary to solve the world's major problems. The International Atomic Energy Agency (IAEA) experience, its formal Statute, and its staff were considered as the basis for projecting a model of world order. An autonomous body related to the United Nations, the successes which the IAEA has enjoyed were considered the result of the sound processes and principles on which it is based.

  4. Lab-on-a-brane: nanofibrous polymer membranes to recreate organ-capillary interfaces

    Science.gov (United States)

    Budhwani, Karim I.; Thomas, Vinoy; Sethu, Palaniappan

    2016-03-01

    Drug discovery is a complex and time consuming process involving significant basic research and preclinical evaluation prior to testing in patients. Preclinical studies rely extensively on animal models which often fail in human trials. Biomimetic microphysiological systems (MPS) using human cells can be a promising alternative to animal models; where critical interactions between different organ systems are recreated to provide physiologically relevant in vitro human models. Central here are blood-vessel networks, the interface controlling transport of cellular and biomolecular components between the circulating fluid and underlying tissue. Here we present a novel lab-on-a-brane (or lab-on-a-membrane) nanofluidics MPS that combines the elegance of lab-on-a-chip with the more realistic morphology of 3D fibrous tissue-engineering constructs. Our blood-vessel lab-on-a-brane effectively simulates in vivo vessel-tissue interface for evaluating transendothelial transport in various pharmacokinetic and nanomedicine applications. Attributes of our platform include (a) nanoporous barrier interface enabling transmembrane molecular transport, (b) transformation of substrate into nanofibrous 3D tissue matrix, (c) invertible-sandwich architecture, and (d) simple co-culture mechanism for endothelial and smooth muscle layers to accurately mimic arterial anatomy. Structural, mechanical, and transport characterization using scanning electron microscopy, stress/strain analysis, infrared spectroscopy, immunofluorescence, and FITC-Dextran hydraulic permeability confirm viability of this in vitro system. Thus, our lab-on-a-brane provides an effective and efficient, yet considerably inexpensive, physiologically relevant alternative for pharmacokinetic evaluation; possibly reducing animals used in preclinical testing, costs from false starts, and time-to-market. Furthermore, it can be configured in multiple simultaneous arrays for personalized and precision medicine applications and for

  5. 2-branes with Arnold-Beltrami fluxes from minimal D = 7 supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Fre, P. [Dipartimento di Fisica, Universita di Torino (Italy); National Research Nuclear University MEPhI, (Moscow Engineering Physics Institute), Moscow (Russian Federation); INFN, Sezione di Torino (Italy); Sorin, A.S. [Bogoliubov Laboratory of Theoretical Physics and Veksler and Baldin Laboratory of High Energy Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Nuclear University MEPhI, (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-07-15

    We describe this paper as a Sentimental Journey from Hydrodynamics to Supergravity. Beltrami equation in three dimensions that plays a key role in the hydrodynamics of incompressible fluids has an unsuspected relation with minimal supergravity in seven dimensions. We show that just D = 7 supergravity and no other theory with the same field content but different coefficients in the lagrangian, admits exact two-brane solutions where Arnold-Beltrami fluxes in the transverse directions have been switched on. The rich variety of discrete groups that classify the solutions of Beltrami equation, namely the eigenfunctions of the *d operator on a three-torus, are by this newly discovered token injected into the brane world. A new quite extensive playing ground opens up for supergravity and for its dual gauge theories in three dimensions, where all classical fields and all quantum composite operators will be assigned to irreducible representations of discrete crystallographic groups Γ. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. The evolution of Brown-York quasilocal energy due to evolution of Lovelock gravity in a system of M0-branes

    OpenAIRE

    Sepehri, Alireza; Rahaman, Farook; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh

    2016-01-01

    Recently, it has been suggested in [JHEP 12(2015)003] that the Brown-York mechanism can be used to measure the quasilocal energy in Lovelock gravity. We have used this method in a system of M0-branes and show that the Brown-York energy evolves in the process of birth and growth of Lovelock gravity. This can help us to predict phenomenological events which are emerged as due to dynamical structure of Lovelock gravity in our universe. In this model, first, M0-branes join to each other and form ...

  7. Chiral Four-Dimensional N=1 Supersymmetric Type IIA Orientifolds from Intersecting D6-Branes

    CERN Document Server

    Cvetic, M; Uranga, Angel M; Cvetic, Mirjam; Shiu, Gary; Uranga, Angel M.

    2001-01-01

    We construct N=1 supersymmetric four-dimensional orientifolds of type IIA on T^6/(Z_2 x Z_2) with D6-branes intersecting at angles. The use of D6-branes not fully aligned with the O6-planes in the model allows for a construction of many supersymmetric models with chiral matter, including those with the Standard Model and grand unified gauge groups. We perform a search for realistic gauge sectors, and construct the first example of a supersymmetric type II orientifold with SU(3)_C x SU(2)_L x U(1)_Y gauge group and three quark-lepton families. In addition to the supersymmetric Standard Model content, the model contains right-handed neutrinos, a (chiral but anomaly-free) set of exotic multiplets, and diverse vector-like multiplets. The general class of these constructions are related to familiar type II orientifolds by small instanton transitions, which in some cases change the number of generations, as discussed in specific models. These constructions are supersymmetric only for special choices of untwisted mo...

  8. Rotating NS5-brane solution and its exact string theoretical description

    OpenAIRE

    Sfetsos, K.

    1999-01-01

    We construct the most general solution in type-II string theory that represents N coincident non-extremal rotating NS5-branes and determine the relevant thermodynamic quantities. We show that in the field theory limit, it has an exact description. In particular, it can be obtained by an O(3,3) duality transformation on the exact string background for the coset model SL(2,R)_{-N}/U(1) \\times SU(2)_N. In the extreme supersymmetric limit we recover the multicenter solution, with a ring singulari...

  9. E{sub 6} Yukawa couplings in F-theory as D-brane instanton effects

    Energy Technology Data Exchange (ETDEWEB)

    Collinucci, Andrés [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles, C.P. 231, 1050 Bruxelles (Belgium); García-Etxebarria, Iñaki [Max Planck Institute for Physics,Föhringer Ring 6, 80805 Munich (Germany)

    2017-03-29

    At weak coupling the neighborhood of a E{sub 6} Yukawa point in SU(5) GUT F-theory models is described by a non-resolvable orientifold of the conifold. We explicitly show, first directly in IIB and then via a mirror symmetry argument, that in this limit the E{sub 6} Yukawa coupling is better described as coming from the non-perturbative contribution of a euclidean D1-brane wrapping the non-resolvable cycle. We also discuss how the M-theory description interpolates between the weak and strong coupling viewpoints.

  10. Towards multi-field D-brane inflation in a warped throat

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Heng-Yu [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI53706-1390 (United States); Gong, Jinn-Ouk [Instituut-Lorentz for Theoretical Physics, Universiteit Leiden, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Koyama, Kazuya [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Tasinato, Gianmassimo, E-mail: hchen46@wisc.edu, E-mail: jgong@lorentz.leidenuniv.nl, E-mail: Kazuya.Koyama@port.ac.uk, E-mail: G.Tasinato@thphys.uni-heidelberg.de [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, 69120, Heidelberg (Germany)

    2010-11-01

    We study the inflationary dynamics in a model of slow-roll inflation in warped throat. Inflation is realized by the motion of a D-brane along the radial direction of the throat, and at later stages instabilities develop in the angular directions. We closely investigate both the single field potential relevant for the slow-roll phase, and the full multi-field one including the angular modes which becomes important at later stages. We study the main features of the instability process, discussing its possible consequences and identifying the vacua towards which the angular modes are driven.

  11. A new world lakes database for global hydrological modelling

    Science.gov (United States)

    Pimentel, Rafael; Hasan, Abdulghani; Isberg, Kristina; Arheimer, Berit

    2017-04-01

    Lakes are crucial systems in global hydrology, they constitutes approximately a 65% of the total amount of surface water over the world. The recent advances in remote sensing technology have allowed getting new higher spatiotemporal resolution for global water bodies information. Within them, ESA global map of water bodies, stationary map at 150 m spatial resolution, (Lamarche et al., 2015) and the new high-resolution mapping of global surface water and its long-term changes, 32 years product with a 30 m spatial resolution (Pekel et al., 2016). Nevertheless, these databases identifies all the water bodies, they do not make differences between lakes, rivers, wetlands and seas. Some global databases with isolate lake information are available, i.e. GLWD (Global Lakes and Wetland Database) (Lernhard and Döll, 2004), however the location of some of the lakes is shifted in relation with topography and their extension have also experimented changes since the creation of the database. This work presents a new world lake database based on ESA global map water bodies and relied on the lakes in GLWD. Lakes from ESA global map of water bodies were identified using a flood fill algorithm, which is initialized using the centroid of the lakes defined in GLWD. Some manual checks were done to split lakes that are really connected but identified as different lakes in GLWD database. In this way the database associated information provided in GLDW is maintained. Moreover, the locations of the outlet of all them were included in the new database. The high resolution upstream area information provided by Global Width Database for Large Rivers (GWD-LR) was used for that. This additional points location constitutes very useful information for watershed delineation by global hydrological modelling.. The methodology was validated using in situ information from Sweden lakes and extended over the world. 13 500 lakes greater than 0.1 km2 were identified.

  12. Tachyon Condensation and Spectrum of Strings on D-branes

    OpenAIRE

    Suyama, Takao

    2001-01-01

    We investigate spectrum of open strings on D-branes after tachyon condensation in bosonic string theory. We calculate 1-loop partition function of the string and show that its limiting forms coincide with partition functions of open strings with different boundary conditions.

  13. V = 1 super quantum chromodynamics and fractional branes

    Indian Academy of Sciences (India)

    INFN, Sezione di Napoli and Dipartimento di Scienze Fisiche dell'Universitиa,. Complesso Universitario di Monte S. Angelo, via Cintia, ed. G I-80126 Napoli, Italy. Abstract. In this talk we show how to get the one-loop beta function and the chiral anomaly of Ж = 1 super QCD from a stack of fractional V D3-branes localized ...

  14. Mirror symmetry, toric branes and topological string amplitudes as polynomials

    Energy Technology Data Exchange (ETDEWEB)

    Alim, Murad

    2009-07-13

    The central theme of this thesis is the extension and application of mirror symmetry of topological string theory. The contribution of this work on the mathematical side is given by interpreting the calculated partition functions as generating functions for mathematical invariants which are extracted in various examples. Furthermore the extension of the variation of the vacuum bundle to include D-branes on compact geometries is studied. Based on previous work for non-compact geometries a system of differential equations is derived which allows to extend the mirror map to the deformation spaces of the D-Branes. Furthermore, these equations allow the computation of the full quantum corrected superpotentials which are induced by the D-branes. Based on the holomorphic anomaly equation, which describes the background dependence of topological string theory relating recursively loop amplitudes, this work generalizes a polynomial construction of the loop amplitudes, which was found for manifolds with a one dimensional space of deformations, to arbitrary target manifolds with arbitrary dimension of the deformation space. The polynomial generators are determined and it is proven that the higher loop amplitudes are polynomials of a certain degree in the generators. Furthermore, the polynomial construction is generalized to solve the extension of the holomorphic anomaly equation to D-branes without deformation space. This method is applied to calculate higher loop amplitudes in numerous examples and the mathematical invariants are extracted. (orig.)

  15. The M5-brane and non-commutative open strings

    NARCIS (Netherlands)

    Bergshoeff, E.; Berman, D.S.; Schaar, J.P. van der; Sundell, P.

    2001-01-01

    The M-theory origin of non-commutative open-string theory is examined by investigating the M-theory 5-brane at near critical field strength. In particular, it is argued that the open-membrane metric provides the appropriate moduli when calculating the duality relations between M and II

  16. Super p-brane theories and new spacetime superalgebras

    NARCIS (Netherlands)

    Bergshoeff, E.; Sezgin, E.

    1995-01-01

    We present a geometric formulation of super p-brane theories in which the Wess-Zumino term is (p + 1)-th order in the supersymmetric currents, and hence is manifestly supersymmetric. The currents are constructed using a supergroup manifold corresponding to a generalization of a superalgebra which we

  17. Football business models: Why did Germany win the World Cup?

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2016-01-01

    This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup.......This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup....

  18. Football business models: Why did Germany win the World Cup?

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2014-01-01

    This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup.......This article looks into the managerial aspects related to why and how Germany won the 2014 FIFA World Cup....

  19. Effective World Modeling: Multisensor Data Fusion Methodology for Automated Driving

    Directory of Open Access Journals (Sweden)

    Jos Elfring

    2016-10-01

    Full Text Available The number of perception sensors on automated vehicles increases due to the increasing number of advanced driver assistance system functions and their increasing complexity. Furthermore, fail-safe systems require redundancy, thereby increasing the number of sensors even further. A one-size-fits-all multisensor data fusion architecture is not realistic due to the enormous diversity in vehicles, sensors and applications. As an alternative, this work presents a methodology that can be used to effectively come up with an implementation to build a consistent model of a vehicle’s surroundings. The methodology is accompanied by a software architecture. This combination minimizes the effort required to update the multisensor data fusion system whenever sensors or applications are added or replaced. A series of real-world experiments involving different sensors and algorithms demonstrates the methodology and the software architecture.

  20. Effective World Modeling: Multisensor Data Fusion Methodology for Automated Driving.

    Science.gov (United States)

    Elfring, Jos; Appeldoorn, Rein; van den Dries, Sjoerd; Kwakkernaat, Maurice

    2016-10-11

    The number of perception sensors on automated vehicles increases due to the increasing number of advanced driver assistance system functions and their increasing complexity. Furthermore, fail-safe systems require redundancy, thereby increasing the number of sensors even further. A one-size-fits-all multisensor data fusion architecture is not realistic due to the enormous diversity in vehicles, sensors and applications. As an alternative, this work presents a methodology that can be used to effectively come up with an implementation to build a consistent model of a vehicle's surroundings. The methodology is accompanied by a software architecture. This combination minimizes the effort required to update the multisensor data fusion system whenever sensors or applications are added or replaced. A series of real-world experiments involving different sensors and algorithms demonstrates the methodology and the software architecture.

  1. Proposition Factor Model of World Class Manufacturing in Brazilian Enterprises

    Directory of Open Access Journals (Sweden)

    Paulo Sergio Gonçalves de Oliveira

    2016-05-01

    Full Text Available The present paper aims to develop a model of World Class Manufacturing, to achieve this goal was elaborated a questionnaire with 35 assertive divided in 7 areas suggested by literature review. This questionnaire was send to manufacture specialists, product developers and technician through LinkedIn the participants was select by researchers in discussion groups taking in consideration their experience using the professional profile. About 1000 invite was send to professional from metal-mechanic sector which returned 180 valid questionnaires. The data was analyzed through factor analyses and was obtained 7 constructs, which explained 67% of data variance. The KMO was 0,84, which is considered good for, analyzes purpose. The seventh factor was eliminated because it Cranach’s Alpha was below 0,6 and the remained factor was nominated as: Lean Manufacturing, Human Resources Management to achieve flexibility, Marketing Integration, Costs Reduction and Flexibility.

  2. Effective actions and topological strings. Off-shell mirror symmetry and mock modularity of multiple M5-branes

    Energy Technology Data Exchange (ETDEWEB)

    Hecht, Michael

    2011-10-20

    This thesis addresses two different topics within the field of string theory. In the first part it is shown how Hodge-theoretic methods in conjunction with open string mirror symmetry can be used to compute non-perturbative effective superpotential couplings for type II/F-theory compactifications with D-branes and fluxes on compact Calabi-Yau manifolds. This is achieved by studying the at structure of operators which derives from the open/closed {beta}-model geometry. We analyze the variation of mixed Hodge structure of the relative cohomology induced by a family of divisors, which is wrapped by a D7-brane. This leads to a Picard-Fuchs system of differential operators, which can be used to compute the moduli dependence of the superpotential couplings as well as the mirror maps at various points in the open/closed deformation space. These techniques are used to obtain predictions for genuine A-model Ooguri-Vafa invariants of special Lagrangian submanifolds in compact Calabi-Yau geometries and real enumerative invariants of on-shell domain wall tensions. By an open/closed duality the system of differential equations can also be obtained from a gauged linear {sigma}-model, which describes a non-compact Calabi-Yau four-fold compactification without branes. This is used in the examples of multi-parameter models to study the various phases of the combined open/closed deformation space. It is furthermore shown how the brane geometry can be related to a F-theory compactification on a compact Calabi-Yau four-fold, where the Hodge-theoretic techniques can be used to compute the G-flux induced Gukov-Vafa-Witten potential. The dual F-theory picture also allows to conjecture the form of the Kaehler potential on the full open/closed deformation space. In the second part we analyze the background dependence of theories which derive from multiple wrapped M5-branes. Using the Kontsevich-Soibelman wall-crossing formula and the theory of mock modular forms we derive a holomorphic

  3. The Gravity of Dark Vortices: Effective Field Theory for Branes and Strings Carrying Localized Flux

    CERN Document Server

    Burgess, C P; Williams, M

    2015-01-01

    A Nielsen-Olesen vortex usually sits in an environment that expels the flux that is confined to the vortex, so flux is not present both inside and outside. We construct vortices for which this is not true, where the flux carried by the vortex also permeates the `bulk' far from the vortex. The idea is to mix the vortex's internal gauge flux with an external flux using off-diagonal kinetic mixing. Such `dark' vortices could play a phenomenological role in models with both cosmic strings and a dark gauge sector. When coupled to gravity they also provide explicit ultra-violet completions for codimension-two brane-localized flux, which arises in extra-dimensional models when the same flux that stabilizes extra-dimensional size is also localized on space-filling branes situated around the extra dimensions. We derive simple formulae for observables such as defect angle, tension, localized flux and on-vortex curvature when coupled to gravity, and show how all of these are insensitive to much of the microscopic detail...

  4. Solutions on a brane in a bulk spacetime with Kalb–Ramond field

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Sumanta, E-mail: sumanta@iucaa.in; SenGupta, Soumitra, E-mail: tpssg@iacs.res.in

    2016-04-15

    Effective gravitational field equations on a brane have been derived, when the bulk spacetime is endowed with the second rank antisymmetric Kalb–Ramond field. Since both the graviton and the Kalb–Ramond field are closed string excitations, they can propagate in the bulk. After deriving the effective gravitational field equations on the brane, we solve them for a static spherically symmetric solution. It turns out that the solution so obtained represents a black hole or naked singularity depending on the parameter space of the model. The stability of this model is also discussed. Cosmological solutions to the gravitational field equations have been obtained, where the Kalb–Ramond field is found to behave as normal pressure free matter. For certain specific choices of the parameters in the cosmological solution, the solution exhibits a transition in the behaviour of the scale factor and hence a transition in the expansion history of the universe. The possibility of accelerated expansion of the universe in this scenario is also discussed.

  5. On effective actions of BPS branes and their higher derivative corrections

    CERN Document Server

    Hatefi, Ehsan

    2010-01-01

    We calculate in detail the disk level S-matrix element of one Ramond-Ramond field and three gauge field vertex operators in the world volume of BPS branes, to find four gauge field couplings to all orders of $\\alpha'$ up to on-shell ambiguity. Then using these infinite couplings we find that the massless pole of the field theory amplitude is exactly equal to the massless pole S-matrix element of this amplitude for the $p=n$ case to all orders of $\\alpha'$. Finally we show that the infinite massless poles and the contact terms of this amplitude for the $p=n+2$ case can be reproduced by the Born-Infeld action and the Wess-Zumino actions, and by their higher derivative corrections.

  6. The FGK formalism for black p-branes in d dimensions

    Science.gov (United States)

    de Antonio Martín, Antonio; Ortín, Tomás; Shahbazi, C. S.

    2012-05-01

    We present a generalization to an arbitrary number of spacetime ( d) and world-volume ( p + 1) dimensions of the formalism proposed by Ferrara, Gibbons and Kallosh to study black holes ( p = 0) in d = 4 dimensions. We include the special cases in which there can be dyonic and self- or anti-self-dual black branes. Most of the results valid for 4-dimensional black holes (relations between temperature, entropy and non-extremality parameter, and between entropy and black-hole potential on the horizon) are straightforwardly generalized. We apply the formalism to the case of black strings in N = 2 , d = 5 supergravity coupled to vector multiplets, in which the black-string potential can be expressed in terms of the dual central charge and work out an explicit example with one vector multiplet, determining supersymmetric and non-supersymmetric attractors and constructing the nonextremal black-string solutions that interpolate between them.

  7. Microstates of D1–D5(-P black holes, as interacting D-branes

    Directory of Open Access Journals (Sweden)

    Takeshi Morita

    2015-07-01

    Full Text Available In our previous study (Morita et al., 2014 [1], we figured out that the thermodynamics of the near extremal black p-branes can be explained as the collective motions of gravitationally interacting elementary p-branes (the p-soup proposal. We test this proposal in the near-extremal D1–D5 and D1–D5-P black holes and show that their thermodynamics also can be explained in a similar fashion, i.e. via the collective motions of the interacting elementary D1-branes and D5-branes (and waves. It may imply that the microscopic origins of these intersecting black branes and the black p-brane are explained in the unified picture. We also argue the relation between the p-soup proposal and the conformal field theory calculations of the D1–D5(-P black holes in superstring theory.

  8. Understanding virtual world usage : A multipurpose model and empirical testing

    NARCIS (Netherlands)

    Verhagen, Tibert; Feldberg, Frans; Van Den Hooff, Bart; Meents, Selmar

    2009-01-01

    This study reports an attempt to enhance our understanding of the reasons behind virtual world usage. By providing a mixture of utilitarian and hedonic value, virtual worlds represent an emerging class of multipurpose information systems (MPIS). Previous research seems to fall short in explaining

  9. Large dimensions and small curvatures from supersymmetric brane back-reaction

    Science.gov (United States)

    Burgess, C. P.; van Nierop, L.

    2011-04-01

    We compute the back-reaction of pairs of codimension-two branes within an explicit flux-stabilized compactification, to trace how its properties depend on the parameters that define the brane-bulk couplings. Both brane tension and magnetic couplings to the stabilizing flux play an important role in the resulting dynamics, with the magnetic coupling allowing some of the flux to be localized on the branes (thus changing the flux-quantization conditions). We find that back-reaction lifts the classical flat directions of the bulk supergravity, and we calculate both the scalar potential and changes to the extra-dimensional and on-brane geometries that result, as functions of the assumed brane couplings. When linearized about simple rugby-ball geometries the resulting solutions allow a systematic exploration of the system's response. Several of the systems we explore have remarkable properties. Among these are a propensity for the extra dimensions to stabilize at exponentially large sizes, providing a mechanism for generating extremely large volumes. In some circumstances the brane-dilaton coupling allows the bulk dilaton to adjust to suppress the on-brane curvature parametrically below the change in brane tension, potentially providing a mechanism for reducing the vacuum energy. We explore the stability of this suppression to quantum effects in the case where their strength is controlled by the value of the field along the classical flat direction, and find it can (but need not) be stable.

  10. D branes in background fluxes and Nielsen-Olesen instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Jorge G. [Institució Catalana de Recerca i Estudis Avançats (ICREA),Pg. Lluis Companys, 23, 08010 Barcelona (Spain); Department de Fisica Cuantica i Astrofisica and Institut de Ciències del Cosmos,Universitat de Barcelona, Martí Franquès, 1, 08028 Barcelona (Spain)

    2016-06-06

    In quantum field theory, charged particles with spin ≥1 may become tachyonic in the present of magnetic fluxes above some critical field, signaling an instability of the vacuum. The phenomenon is generic, in particular, similar instabilities are known to exist in open and closed string theory, where a spinning string state can become tachyonic above a critical field. In compactifications involving RR fluxes F{sub p+2}, the quantum states which could become tachyonic by the same Nielsen-Olesen mechanism are Dp branes. By constructing an appropriate background with RR magnetic flux that takes into account back-reaction, we identify the possible tachyonic Dp brane states and compute the formula for the energy spectrum in a sector. More generally, we argue that in any background RR magnetic flux, there are high spin Dp quantum states which become very light at critical fields.

  11. Romans-mass-driven flows on the D2-brane

    Energy Technology Data Exchange (ETDEWEB)

    Guarino, Adolfo [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); Tarrío, Javier [Physique Théorique et Mathématique, Université Libre de Bruxellesand International Solvay Institutes,ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Varela, Oscar [Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut),Am Mühlenberg 1, D-14476 Potsdam (Germany); Department of Physics, Utah State University,Logan, UT 84322 (United States)

    2016-08-30

    The addition of supersymmetric Chern-Simons terms to N=8 super-Yang-Mills theory in three-dimensions is expected to make the latter flow into infrared superconformal phases. We address this problem holographically by studying the effect of the Romans mass on the D2-brane near-horizon geometry. Working in a consistent, effective four-dimensional setting provided by D=4N=8 supergravity with a dyonic ISO(7) gauging, we verify the existence of a rich web of supersymmetric domain walls triggered by the Romans mass that interpolate between the (four-dimensional description of the) D2-brane and various superconformal phases. We also construct domain walls for which both endpoints are superconformal. While most of our results are numerical, we provide analytic results for the SU(3)×U(1)-invariant flow into an N=2 conformal phase recently discovered.

  12. Thick brane in f( R) gravity with Palatini dynamics

    Science.gov (United States)

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

    2015-12-01

    This work deals with modified gravity in five-dimensional space-time. We study a thick Palatini f( R) brane, that is, a braneworld scenario described by an anti-de Sitter warped geometry with a single extra dimension of infinite extent, sourced by a real scalar field under the Palatini approach, where the metric and the connection are regarded as independent degrees of freedom. We consider a first-order framework which we use to provide exact solutions for the scalar field and warp factor. We also investigate a perturbative scenario such that the Palatini approach is implemented through a Lagrangian f(R)=R+ɛ R^n, where the small parameter ɛ controls the deviation from the standard thick brane case. In both cases it is found that the warp factor tends to localize the extra dimension due to the nonlinear corrections.

  13. Canonical quantization of a string describing N branes at angles

    Directory of Open Access Journals (Sweden)

    Igor Pesando

    2014-12-01

    The splitting of the string coordinates into a classical and quantum part allows the formulation of an improved overlap principle. Using this approach we then proceed in computing the generating function for the generic correlator with L untwisted operators and N (excited twist fields for branes at angles. We recover as expected the results previously obtained using the path integral. This construction explains why these correlators are given by a generalization of the Wick theorem.

  14. Holographic Schwinger effect with a moving D3-brane

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zi-qiang; Chen, Gang [China University of Geosciences (Wuhan), School of Mathematics and Physics, Wuhan (China); Hou, De-fu [Central China Normal University, Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOS), Wuhan (China)

    2017-03-15

    We study the Schwinger effect with a moving D3-brane in a N = 4 SYM plasma with the aid of AdS/CFT correspondence. We discuss the test particle pair moving transverse and parallel to the plasma wind, respectively. It is found that for both cases the presence of velocity tends to increase the Schwinger effect. In addition, the velocity has a stronger influence on the Schwinger effect when the pair moves transverse to the plasma wind rather than parallel. (orig.)

  15. Quasi-homologous spherically symmetric branes and their symmetry breaking

    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)

    2013-06-15

    We revisit the dynamical system-based approach of spherically symmetric vacuum braneworlds, pointing out and studying the existence of a transcritical bifurcation as the dark pressure parameter changes its sign, we analyze some consequences of not discard the brane cosmological constant. For instance, it is noteworthy that the existence of an isothermal state equation between the dark fluid parameters cannot be obtained via the requirement of a quasi-homologous symmetry of the vacuum. (orig.)

  16. Identification of market trends with string and D2-brane maps

    Science.gov (United States)

    Bartoš, Erik; Pinčák, Richard

    2017-08-01

    The multidimensional string objects are introduced as a new alternative for an application of string models for time series forecasting in trading on financial markets. The objects are represented by open string with 2-endpoints and D2-brane, which are continuous enhancement of 1-endpoint open string model. We show how new object properties can change the statistics of the predictors, which makes them the candidates for modeling a wide range of time series systems. String angular momentum is proposed as another tool to analyze the stability of currency rates except the historical volatility. To show the reliability of our approach with application of string models for time series forecasting we present the results of real demo simulations for four currency exchange pairs.

  17. Charged isotropic non-Abelian dyonic black branes

    Directory of Open Access Journals (Sweden)

    Yves Brihaye

    2015-05-01

    Full Text Available We construct black holes with a Ricci-flat horizon in Einstein–Yang–Mills theory with a negative cosmological constant, which approach asymptotically an AdSd spacetime background (with d≥4. These solutions are isotropic, i.e. all space directions in a hypersurface of constant radial and time coordinates are equivalent, and possess both electric and magnetic fields. We find that the basic properties of the non-Abelian solutions are similar to those of the dyonic isotropic branes in Einstein–Maxwell theory (which, however, exist in even spacetime dimensions only. These black branes possess a nonzero magnetic field strength on the flat boundary metric, which leads to a divergent mass of these solutions, as defined in the usual way. However, a different picture is found for odd spacetime dimensions, where a non-Abelian Chern–Simons term can be incorporated in the action. This allows for black brane solutions with a magnetic field which vanishes asymptotically.

  18. Black and super p-branes in diverse dimensions

    CERN Document Server

    Duff, Michael J

    1994-01-01

    We present a generic Lagrangian, in arbitrary spacetime dimension $D$, describing the interaction of a dilaton, a graviton and an antisymmetric tensor of arbitrary rank $d$. For each $D$~and~$d$, we find ``solitonic'' black $\\tilde{p}$-brane solutions where $\\tilde{p} = \\tilde{d} - 1$~and~ $\\tilde d = D - d - 2$. These solutions display a spacetime singularity surrounded by an event horizon, and are characterized by a mass per unit $\\tilde p$-volume, ${\\cal M}_{\\tilde{d}}$, and topological ``magnetic'' charge $g_{\\tilde{d}}$, obeying $\\kappa {\\cal M}_{\\tilde{d}} \\geq g_{\\tilde{d}}/ \\sqrt{2}$. In the extreme limit $\\kappa {\\cal M}_{\\tilde{d}}=g_{\\tilde{d}}/ \\sqrt{2}$, the singularity and event horizon coalesce. For specific values of $D$~and~$d$, these extreme solutions also exhibit supersymmetry and may be identified with previously classified heterotic, Type IIA and Type IIB super $\\tilde p$-branes. The theory also admits elementary $p$-brane solutions with ``electric'' Noether charge $e_d$, obeying the Dira...

  19. Mathematical Modelling: Transitions between the Real World and the Mathematical Model

    Science.gov (United States)

    Crouch, Rosalind; Haines, Christopher

    2004-01-01

    Applications in engineering, science and technology within undergraduate programmes can be difficult for students to understand. In this paper, new results are presented which go some way to demonstrate and explain the problems faced by students in linking mathematical models to real-world applications. The study is based on student responses to…

  20. Self-interacting scalar field trapped in a DGP brane: The dynamical systems perspective

    Energy Technology Data Exchange (ETDEWEB)

    Quiros, Israel [Departamento de Fisica, Universidad Central de Las Villas, 54830 Santa Clara (Cuba)], E-mail: israel@uclv.edu.cu; Garcia-Salcedo, Ricardo [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria del IPN, Mexico D.F. (Mexico)], E-mail: rigarcias@ipn.mx; Matos, Tonatiuh [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, A.P. 14-740, 07000 Mexico D.F. (Mexico)], E-mail: tmatos@fis.cinvestav.mx; Moreno, Claudia [Departamento de Fisica y Matematicas, Centro Universitario de Ciencias Exactas e Ingenierias, Corregidora 500 S.R., Universidad de Guadalajara, 44420 Guadalajara, Jalisco (Mexico)], E-mail: claudia.moreno@cucei.udg.mx

    2009-01-05

    We apply the dynamical systems tools to study the linear dynamics of a self-interacting scalar field trapped on a DGP brane. The simplest kinds of self-interaction potentials are investigated: (a) constant potential, and (b) exponential potential. It is shown that the dynamics of DGP models can be very rich and complex. One of the most interesting results of this study shows that dynamical screening of the scalar field self-interaction potential, occurring within the Minkowski cosmological phase of the DGP model and that mimics 4D phantom behaviour, is an attractor solution for a constant self-interaction potential but not for the exponential one. In the latter case gravitational screening is not even a critical point of the corresponding autonomous system of ordinary differential equations.

  1. Type IIB orientifolds, D-brane instantons and the LARGE volume scenario

    Energy Technology Data Exchange (ETDEWEB)

    Plauschinn, E. [Institute for Theoretical Physics, Utrecht University, Utrecht (Netherlands)

    2010-10-15

    This review article is concerned with three topics important for the construction of four-dimensional models of particle physics in the context of type II String Theories. Special emphasis is put on a consistent presentation of these topics as well as on highlighting their interconnections. The first of the three topics deals with the tadpole cancellation conditions and the cancellation of chiral anomalies for type IIB orientifolds with orientifold three- and seven-planes. The second topic is related to non-perturbative effects originating from D-brane instantons. In particular, in the presence of a realistic particle physics sector, a chiral zero-mode constraint for contribution of instantons to the superpotential arises. The third topic is about moduli stabilisation in type IIB string compactifications. Two scenarios, the KKLT and Large Volume Scenario, are reviewed and a model for the latter scenario with the chiral zero-mode constraint taken into account is presented. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. Strong coupling in F-theory and geometrically non-Higgsable seven-branes

    Directory of Open Access Journals (Sweden)

    James Halverson

    2017-06-01

    Full Text Available Geometrically non-Higgsable seven-branes carry gauge sectors that cannot be broken by complex structure deformation, and there is growing evidence that such configurations are typical in F-theory. We study strongly coupled physics associated with these branes. Axiodilaton profiles are computed using Ramanujan's theories of elliptic functions to alternative bases, showing explicitly that the string coupling is O(1 in the vicinity of the brane; that it sources nilpotent SL(2,Z monodromy and therefore the associated brane charges are modular; and that essentially all F-theory compactifications have regions with order one string coupling. It is shown that non-perturbative SU(3 and SU(2 seven-branes are related to weakly coupled counterparts with D7-branes via deformation-induced Hanany–Witten moves on (p,q string junctions that turn them into fundamental open strings; only the former may exist for generic complex structure. D3-brane near these and the Kodaira type II seven-branes probe Argyres–Douglas theories. The BPS states of slightly deformed theories are shown to be dyonic string junctions.

  3. Strong coupling in F-theory and geometrically non-Higgsable seven-branes

    Science.gov (United States)

    Halverson, James

    2017-06-01

    Geometrically non-Higgsable seven-branes carry gauge sectors that cannot be broken by complex structure deformation, and there is growing evidence that such configurations are typical in F-theory. We study strongly coupled physics associated with these branes. Axiodilaton profiles are computed using Ramanujan's theories of elliptic functions to alternative bases, showing explicitly that the string coupling is O (1) in the vicinity of the brane; that it sources nilpotent SL (2 , Z) monodromy and therefore the associated brane charges are modular; and that essentially all F-theory compactifications have regions with order one string coupling. It is shown that non-perturbative SU (3) and SU (2) seven-branes are related to weakly coupled counterparts with D7-branes via deformation-induced Hanany-Witten moves on (p , q) string junctions that turn them into fundamental open strings; only the former may exist for generic complex structure. D3-brane near these and the Kodaira type II seven-branes probe Argyres-Douglas theories. The BPS states of slightly deformed theories are shown to be dyonic string junctions.

  4. Static configurations and evolution of higher dimensional brane-dilaton black hole system

    Energy Technology Data Exchange (ETDEWEB)

    Nakonieczna, Anna [Institute of Physics, Maria Curie-Skłodowska University,Plac Marii Curie-Skłodowskiej 1, 20-031 Lublin (Poland); Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Nakonieczny, Łukasz [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Moderski, Rafał [Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences,ul. Bartycka 18, 00-716 Warsaw (Poland); Rogatko, Marek [Institute of Physics, Maria Curie-Skłodowska University,Plac Marii Curie-Skłodowskiej 1, 20-031 Lublin (Poland)

    2016-12-15

    Static configurations and a dynamical evolution of the system composed of a higher-dimensional spherically symmetric dilaton black hole and the Dirac-Goto-Nambu brane were investigated. The studies were conducted for three values of the dilaton coupling constant, describing the uncoupled case, the low-energy limit of the string theory and dimensionally reduced Klein-Kaluza theories. When the black hole is nonextremal, two types of static configurations are observed, a brane which intersects the black hole horizon and a brane not having any common points with the accompanying black hole. As the number of spacetime dimensions increases, the brane bend in the vicinity of the black hole disappears closer to its horizon. Dynamical evolution of the system results in an expulsion of the black hole from the brane. It proceeds faster for bigger values of the bulk spacetime dimension and thicker branes. The value of the dilatonic coupling constant does not influence neither the static configurations nor the dynamical behavior of the examined nonextremal system. In the extremal dilaton black hole case one obtains expulsion of the brane which is independent on the spacetime dimensionality and the value of the coupling constant. Dynamical studies of the configurations in the extremal case reveal that the course of evolution of the system is similar to the nonextremal one, except for a slightly earlier expulsion of the black hole from the brane.

  5. Modelling Real World Using Stochastic Processes and Filtration

    Directory of Open Access Journals (Sweden)

    Jaeger Peter

    2016-03-01

    Full Text Available First we give an implementation in Mizar [2] basic important definitions of stochastic finance, i.e. filtration ([9], pp. 183 and 185, adapted stochastic process ([9], p. 185 and predictable stochastic process ([6], p. 224. Second we give some concrete formalization and verification to real world examples.

  6. Evolution of a black hole-inhabited brane close to reconnection

    CERN Document Server

    Balek, Vladimír

    2010-01-01

    Last moments of a mini black hole escaping from a brane are studied. It is argued that at the point of reconnection, where the piece of the brane attached to the black hole separates from the rest, the worldsheet of the brane becomes isotropic (light-like). The degenerate mode of evolution, with the worldsheet isotropic everywhere, is investigated. In particular, it is shown that the brane approaches the reconnection point from below if it reconnects within a certain limit distance, and from above if it reconnects beyond that distance. The rate of relaxation to the degenerate mode is established. If the dimension of the brane is $p$, the nondegeneracy, measured by the determinant of the relevant part of the induced metric tensor, falls down as (latitudinal angle)$^{2(p - 1)}$.

  7. Fractional-wrapped branes with rotation, linear motion and background fields

    Directory of Open Access Journals (Sweden)

    Elham Maghsoodi

    2017-09-01

    Full Text Available We obtain two boundary states corresponding to the two folds of a fractional-wrapped Dp-brane, i.e. the twisted version under the orbifold C2/Z2 and the untwisted version. The brane has rotation and linear motion, in the presence of the following background fields: the Kalb–Ramond tensor, a U(1 internal gauge potential and a tachyon field. The rotation and linear motion are inside the volume of the brane. The brane lives in the d-dimensional spacetime, with the orbifold-toroidal structure Tn×R1,d−n−5×C2/Z2 in the twisted sector. Using these boundary states we calculate the interaction amplitude of two parallel fractional Dp-branes with the foregoing setup. Various properties of this amplitude such as the long-range behavior will be analyzed.

  8. Discrete Torsion, (Anti) de Sitter D{sub 4}-Brane and Tunneling

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Abhishek K.; Pandey, P.K.; Singh, Sunita; Kar, Supriya, E-mail: skkar@physics.du.ac.in

    2014-06-15

    We obtain quantum geometries on a vacuum created pair of a (DD{sup ¯}){sub 3}-brane, at a Big Bang singularity, by a local two form on a D{sub 4}-brane. In fact our analysis is provoked by an established phenomenon leading to a pair creation by a gauge field at a black hole horizon by Stephen Hawking in 1975. Importantly, the five dimensional microscopic black holes are described by an effective non-perturbative curvature underlying a discrete torsion in a second order formalism. In the case for a non-propagating torsion, the effective curvature reduces to Riemannian, which in a low energy limit may describe Einstein vacuum in the formalism. In particular, our analysis suggests that a non-trivial space begin with a hot de Sitter brane-Universe underlying a nucleation of a vacuum pair of (DD{sup ¯})-instanton at a Big Bang. A pair of instanton nucleats a D-particle which in turn combines with an anti D-particle to describe a D-string and so on. The nucleation of a pair of higher dimensional pair of brane/anti-brane from a lower dimensional pair may be viewed via an expansion of the brane-Universe upon time. It is in conformity with the conjecture of a branes within a brane presumably in presence of the non-zero modes of two form. Interestingly, we perform a thermal analysis underlying various emergent quantum de Sitter vacua on a D{sub 4}-brane and argue for the plausible tunneling geometries underlying a thermal equilibrium. It is argued that a de Sitter Schwarzschild undergoes quantum tunneling to an AdS-brane Schwarzschild via Nariai and de Sitter topological black hole.

  9. Large Scale Community Detection Using a Small World Model

    Directory of Open Access Journals (Sweden)

    Ranjan Kumar Behera

    2017-11-01

    Full Text Available In a social network, small or large communities within the network play a major role in deciding the functionalities of the network. Despite of diverse definitions, communities in the network may be defined as the group of nodes that are more densely connected as compared to nodes outside the group. Revealing such hidden communities is one of the challenging research problems. A real world social network follows small world phenomena, which indicates that any two social entities can be reachable in a small number of steps. In this paper, nodes are mapped into communities based on the random walk in the network. However, uncovering communities in large-scale networks is a challenging task due to its unprecedented growth in the size of social networks. A good number of community detection algorithms based on random walk exist in literature. In addition, when large-scale social networks are being considered, these algorithms are observed to take considerably longer time. In this work, with an objective to improve the efficiency of algorithms, parallel programming framework like Map-Reduce has been considered for uncovering the hidden communities in social network. The proposed approach has been compared with some standard existing community detection algorithms for both synthetic and real-world datasets in order to examine its performance, and it is observed that the proposed algorithm is more efficient than the existing ones.

  10. Topological duality twist and brane instantons in F-theory

    Energy Technology Data Exchange (ETDEWEB)

    Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei”, Università di Padova andINFN - Sezione di Padova,Via Marzolo 8, I-35131 Padova (Italy)

    2014-06-30

    A variant of the topological twist, involving SL(2,ℤ) dualities and hence named topological duality twist, is introduced and explicitly applied to describe a U(1) N=4 super Yang-Mills theory on a Kähler space with holomorphically space-dependent coupling. Three-dimensional duality walls and two-dimensional chiral theories naturally enter the formulation of the duality twisted theory. Appropriately generalized, this theory is relevant for the study of Euclidean D3-brane instantons in F-theory compactifications. Some of its properties and implications are discussed.

  11. Analytical shear viscosity in hyperscaling violating black brane

    Science.gov (United States)

    Kuang, Xiao-Mei; Wu, Jian-Pin

    2017-10-01

    In this letter, with the use of matching method, we investigate the shear viscosity in a non-relativistic boundary filed theory without hyperscaling symmetry, which is dual to a bulk charged hyperscaling violating black brane. By matching the solutions to the inner region and outer region at the matching region, we analytically obtain that the ratio of shear viscosity and the entropy density is alway 1 / 4 π at zero temperature and finite temperatures. Our results satisfy the Kovtun-Starinets-Son (KSS) bound.

  12. Line operators from M-branes on compact Riemann surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Amariti, Antonio [Physics Department, The City College of the CUNY, 160 Convent Avenue, New York, NY 10031 (United States); Orlando, Domenico [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Reffert, Susanne, E-mail: sreffert@itp.unibe.ch [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2016-12-15

    In this paper, we determine the charge lattice of mutually local Wilson and 't Hooft line operators for class S theories living on M5-branes wrapped on compact Riemann surfaces. The main ingredients of our analysis are the fundamental group of the N-cover of the Riemann surface, and a quantum constraint on the six-dimensional theory. The latter plays a central role in excluding some of the possible lattices and imposing consistency conditions on the charges. This construction gives a geometric explanation for the mutual locality among the lines, fixing their charge lattice and the structure of the four-dimensional gauge group.

  13. M2-Branes in N = 3 Harmonic Superspace

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    E. Ivanov

    2010-01-01

    Full Text Available We give a brief account of the recently proposed N = 3 superfield formulation of the N = 6, 3D superconformal theory of Aharony et al (ABJM describing a low-energy limit of the system of multiple M2-branes on the AdS4×S7/Zk background. This formulation is given in harmonic N = 3 superspace and reveals a number of surprising new features. In particular, the sextic scalar potential of ABJM arises at the on-shell component level as the result of eliminating appropriate auxiliary fields, while there is no explicit superpotential at the off-shell superfield level.

  14. Analytical shear viscosity in hyperscaling violating black brane

    Directory of Open Access Journals (Sweden)

    Xiao-Mei Kuang

    2017-10-01

    Full Text Available In this letter, with the use of matching method, we investigate the shear viscosity in a non-relativistic boundary filed theory without hyperscaling symmetry, which is dual to a bulk charged hyperscaling violating black brane. By matching the solutions to the inner region and outer region at the matching region, we analytically obtain that the ratio of shear viscosity and the entropy density is alway 1/4π at zero temperature and finite temperatures. Our results satisfy the Kovtun–Starinets–Son (KSS bound.

  15. Tachyon logamediate inflation on the brane

    Energy Technology Data Exchange (ETDEWEB)

    Kamali, Vahid; Nik, Elahe Navaee [Bu-Ali Sina University, Department of Physics, Hamedan (Iran, Islamic Republic of)

    2017-07-15

    According to a Barrow solution for the scale factor of the universe, the main properties of the tachyon inflation model in the framework of the RSII braneworld are studied. Within this framework the basic slow-roll parameters are calculated analytically. We compare this inflationary scenario to the latest observational data. The predicted spectral index and the tensor-to-scalar fluctuation ratio are in excellent agreement with those of Planck 2015. The current predictions are consistent with those of viable inflationary models. (orig.)

  16. Decoupling limit and throat geometry of non-susy D3 brane

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    Kuntal Nayek

    2017-03-01

    Full Text Available Recently it has been shown by us that, like BPS Dp branes, bulk gravity gets decoupled from the brane even for the non-susy Dp branes of type II string theories indicating a possible extension of AdS/CFT correspondence for the non-supersymmetric case. In that work, the decoupling of gravity on the non-susy Dp branes has been shown numerically for the general case as well as analytically for some special case. Here we discuss the decoupling limit and the throat geometry of the non-susy D3 brane when the charge associated with the brane is very large. We show that in the decoupling limit the throat geometry of the non-susy D3 brane, under appropriate coordinate change, reduces to the Constable–Myers solution and thus confirming that this solution is indeed the holographic dual of a (non-gravitational gauge theory discussed there. We also show that when one of the parameters of the solution takes a specific value, it reduces, under another coordinate change, to the five-dimensional solution obtained by Csaki and Reece, again confirming its gauge theory interpretation.

  17. Decoupling limit and throat geometry of non-susy D3 brane

    Energy Technology Data Exchange (ETDEWEB)

    Nayek, Kuntal, E-mail: kuntal.nayek@saha.ac.in; Roy, Shibaji, E-mail: shibaji.roy@saha.ac.in

    2017-03-10

    Recently it has been shown by us that, like BPS Dp branes, bulk gravity gets decoupled from the brane even for the non-susy Dp branes of type II string theories indicating a possible extension of AdS/CFT correspondence for the non-supersymmetric case. In that work, the decoupling of gravity on the non-susy Dp branes has been shown numerically for the general case as well as analytically for some special case. Here we discuss the decoupling limit and the throat geometry of the non-susy D3 brane when the charge associated with the brane is very large. We show that in the decoupling limit the throat geometry of the non-susy D3 brane, under appropriate coordinate change, reduces to the Constable–Myers solution and thus confirming that this solution is indeed the holographic dual of a (non-gravitational) gauge theory discussed there. We also show that when one of the parameters of the solution takes a specific value, it reduces, under another coordinate change, to the five-dimensional solution obtained by Csaki and Reece, again confirming its gauge theory interpretation.

  18. F-theory and the landscape of intersecting D7-branes

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Andreas

    2010-02-05

    In this work, the moduli of D7-branes in type IIB orientifold compactifications and their stabilization by fluxes is studied from the perspective of F-theory. In F-theory, the moduli of the D7-branes and the moduli of the orientifold are unified in the moduli space of an elliptic Calabi-Yau manifold. This makes it possible to study flux the stabilization of D7-branes in an elegant manner. To answer phenomenological questions, one has to translate the deformations of the elliptic Calabi-Yau manifold of F-theory back to the positions and the shape of the D7-branes. We address this problem by constructing the homology cycles that are relevant for the deformations of the elliptic Calabi-Yau manifold.We show the viability of our approach for the case of elliptic two- and three-folds. Furthermore, we discuss a consistency conditions related to the intersections between D7-branes and orientifold planes which is automatically fulfilled in F-theory. Finally, we use our results to study the flux stabilization of D7-branes on the orientifold K3 x T{sup 2}/Z{sub 2} using F-theory on K3 x K3. In this context, we derive conditions on the fluxes to stabilize a given configuration of D7-branes. (orig.)

  19. Cosmology from quantum potential in brane–anti-brane system

    Directory of Open Access Journals (Sweden)

    Alireza Sepehri

    2015-09-01

    Full Text Available Recently, some authors removed the big-bang singularity and predicted an infinite age of our universe. In this paper, we show that the same result can be obtained in string theory and M-theory; however, the shape of universe changes in different epochs. In our mechanism, first, N fundamental string decay to N D0–anti-D0-brane. Then, D0-branes join each other, grow and form a six-dimensional brane–antibrane system. This system is unstable, broken and at present the form of four-dimensional universes, one anti-universe in addition to one wormhole are produced. Thus, there isn't any big-bang in cosmology and the universe is a fundamental string at the beginning. Also, the total age of universe contains two parts, one is related to initial age and the other corresponds to the present age of universe (ttot=tinitial+tpresent. On the other hand, the initial age of universe includes two parts, the age of fundamental string and the time of transition (tinitial=ttransition+tf-string. We observe that only in the case of (tf-string→∞, the scale factor of universe is zero and as a result, the total age of universe is infinity.

  20. Particle actions and brane tensions from double and exceptional geometry

    Science.gov (United States)

    Blair, Chris D. A.

    2017-10-01

    Massless particles in n + 1 dimensions lead to massive particles in n dimensions on Kaluza-Klein reduction. In string theory, wrapped branes lead to multiplets of massive particles in n dimensions, in representations of a duality group G. By encoding the masses of these particles in auxiliary worldline scalars, also transforming under G, we write an action which resembles that for a massless particle on an extended spacetime. We associate this extended spacetime with that appearing in double field theory and exceptional field theory, and formulate a version of the action which is invariant under the generalised diffeomorphism symmetry of these theories. This provides a higher-dimensional perspective on the origin of mass and tension in string theory and M-theory. Finally, we consider the reduction of exceptional field theory on a twisted torus, which is known to give the massive IIA theory of Romans. In this case, our particle action leads naturally to the action for a D0 brane in massive IIA. Here an extra vector field is present on the worldline, whose origin in exceptional field theory is a vector field introduced to ensure invariance under generalised diffeomorphisms.