One-scale supersymmetric inflationary models
International Nuclear Information System (INIS)
Bertolami, O.; Ross, G.G.
1986-01-01
The reheating phase is studied in a class of supergravity inflationary models involving a two-component hidden sector in which the scale of supersymmetry breaking and the scale generating inflation are related. It is shown that these models have an ''entropy crisis'' in which there is a large entropy release after nucleosynthesis leading to unacceptable low nuclear abundances. (orig.)
International Nuclear Information System (INIS)
Witt, B. de
2002-01-01
It is a comprehensive introduction to supergravities in different dimensions and with various numbers of supersymmetries. Topics covered include the allowed low-energy couplings, duality symmetries, compactification and supersymmetries in curved backgrounds. This document is made up of 7 chapters: 1) introduction, 2) supersymmetry in various dimensions, 3) supergravity, 4) homogeneous spaces and non-linear sigma models, 5) gauged maximal supergravity in 4 and 5 dimensions, 6) supersymmetry in anti-Sitter space, and 7) superconformal symmetry. (A.C.)
Supergravity contributions to inflation in models with non-minimal coupling to gravity
Energy Technology Data Exchange (ETDEWEB)
Das, Kumar; Dutta, Koushik [Theory Division, Saha Institute of Nuclear Physics, 1/AF Saltlake, Kolkata 700064 (India); Domcke, Valerie, E-mail: kumar.das@saha.ac.in, E-mail: valerie.domcke@apc.univ-paris7.fr, E-mail: koushik.dutta@saha.ac.in [AstroParticule et Cosmologie (APC), Paris Centre for Cosmological Physics (PCCP), Université Paris Diderot, 75013 Paris (France)
2017-03-01
This paper provides a systematic study of supergravity contributions relevant for inflationary model building in Jordan frame supergravity. In this framework, canonical kinetic terms in the Jordan frame result in the separation of the Jordan frame scalar potential into a tree-level term and a supergravity contribution which is potentially dangerous for sustaining inflation. We show that if the vacuum energy necessary for driving inflation originates dominantly from the F-term of an auxiliary field (i.e. not the inflaton), the supergravity corrections to the Jordan frame scalar potential are generically suppressed. Moreover, these supergravity contributions identically vanish if the superpotential vanishes along the inflationary trajectory. On the other hand, if the F-term associated with the inflaton dominates the vacuum energy, the supergravity contributions are generically comparable to the globally supersymmetric contributions. In addition, the non-minimal coupling to gravity inherent to Jordan frame supergravity significantly impacts the inflationary model depending on the size and sign of this coupling. We discuss the phenomenology of some representative inflationary models, and point out the relation to the recently much discussed cosmological 'attractor' models.
Supergravity contributions to inflation in models with non-minimal coupling to gravity
International Nuclear Information System (INIS)
Das, Kumar; Dutta, Koushik; Domcke, Valerie
2017-01-01
This paper provides a systematic study of supergravity contributions relevant for inflationary model building in Jordan frame supergravity. In this framework, canonical kinetic terms in the Jordan frame result in the separation of the Jordan frame scalar potential into a tree-level term and a supergravity contribution which is potentially dangerous for sustaining inflation. We show that if the vacuum energy necessary for driving inflation originates dominantly from the F-term of an auxiliary field (i.e. not the inflaton), the supergravity corrections to the Jordan frame scalar potential are generically suppressed. Moreover, these supergravity contributions identically vanish if the superpotential vanishes along the inflationary trajectory. On the other hand, if the F-term associated with the inflaton dominates the vacuum energy, the supergravity contributions are generically comparable to the globally supersymmetric contributions. In addition, the non-minimal coupling to gravity inherent to Jordan frame supergravity significantly impacts the inflationary model depending on the size and sign of this coupling. We discuss the phenomenology of some representative inflationary models, and point out the relation to the recently much discussed cosmological 'attractor' models.
Freedman, Daniel Z
2012-01-01
Supergravity, together with string theory, is one of the most significant developments in theoretical physics. Written by two of the most respected workers in the field, this is the first-ever authoritative and systematic account of supergravity. The book starts by reviewing aspects of relativistic field theory in Minkowski spacetime. After introducing the relevant ingredients of differential geometry and gravity, some basic supergravity theories (D=4 and D=11) and the main gauge theory tools are explained. In the second half of the book, complex geometry and N=1 and N=2 supergravity theories are covered. Classical solutions and a chapter on AdS/CFT complete the book. Numerous exercises and examples make it ideal for Ph.D. students, and with applications to model building, cosmology and solutions of supergravity theories, it is also invaluable to researchers.
Curvaton reheating in a logamediate inflationary model
International Nuclear Information System (INIS)
Campo, Sergio del; Herrera, Ramon; Saavedra, Joel; Campuzano, Cuauhtemoc; Rojas, Efrain
2009-01-01
In a logamediate inflationary universe model we introduce the curvaton field in order to bring this inflationary model to an end. In this approach we determine the reheating temperature. We also outline some interesting constraints on the parameters that describe our models. Thus, we give the parameter space in this scenario.
Warm anisotropic inflationary universe model
International Nuclear Information System (INIS)
Sharif, M.; Saleem, Rabia
2014-01-01
This paper is devoted to the study of warm inflation using vector fields in the background of a locally rotationally symmetric Bianchi type I model of the universe. We formulate the field equations, and slow-roll and perturbation parameters (scalar and tensor power spectra as well as their spectral indices) in the slow-roll approximation. We evaluate all these parameters in terms of the directional Hubble parameter during the intermediate and logamediate inflationary regimes by taking the dissipation factor as a function of the scalar field as well as a constant. In each case, we calculate the observational parameter of interest, i.e., the tensor-scalar ratio in terms of the inflaton. The graphical behavior of these parameters shows that the anisotropic model is also compatible with WMAP7 and the Planck observational data. (orig.)
Warm anisotropic inflationary universe model
Energy Technology Data Exchange (ETDEWEB)
Sharif, M.; Saleem, Rabia [University of the Punjab, Department of Mathematics, Lahore (Pakistan)
2014-02-15
This paper is devoted to the study of warm inflation using vector fields in the background of a locally rotationally symmetric Bianchi type I model of the universe. We formulate the field equations, and slow-roll and perturbation parameters (scalar and tensor power spectra as well as their spectral indices) in the slow-roll approximation. We evaluate all these parameters in terms of the directional Hubble parameter during the intermediate and logamediate inflationary regimes by taking the dissipation factor as a function of the scalar field as well as a constant. In each case, we calculate the observational parameter of interest, i.e., the tensor-scalar ratio in terms of the inflaton. The graphical behavior of these parameters shows that the anisotropic model is also compatible with WMAP7 and the Planck observational data. (orig.)
Constrained superfields in supergravity
Energy Technology Data Exchange (ETDEWEB)
Dall’Agata, Gianguido; Farakos, Fotis [Dipartimento di Fisica ed Astronomia “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy)
2016-02-16
We analyze constrained superfields in supergravity. We investigate the consistency and solve all known constraints, presenting a new class that may have interesting applications in the construction of inflationary models. We provide the superspace Lagrangians for minimal supergravity models based on them and write the corresponding theories in component form using a simplifying gauge for the goldstino couplings.
Gravitational waves in hybrid quintessential inflationary models
Energy Technology Data Exchange (ETDEWEB)
Sa, Paulo M [Departamento de Fisica, Faculdade de Ciencias e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Henriques, Alfredo B, E-mail: pmsa@ualg.pt, E-mail: alfredo.henriques@ist.utl.pt [Centro Multidisciplinar de Astrofisica - CENTRA and Departamento de Fisica, Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)
2011-09-22
The generation of primordial gravitational waves is investigated within the hybrid quintessential inflationary model. Using the method of continuous Bogoliubov coefficients, we calculate the full gravitational-wave energy spectrum. The post-inflationary kination period, characteristic of quintessential inflationary models, leaves a clear signature on the spectrum, namely, a sharp rise of the gravitational-wave spectral energy density {Omega}{sub GW} at high frequencies. For appropriate values of the parameters of the model, {Omega}{sub GW} can be as high as 10{sup -12} in the MHz-GHz range of frequencies.
Gravitational waves in hybrid quintessential inflationary models
International Nuclear Information System (INIS)
Sa, Paulo M; Henriques, Alfredo B
2011-01-01
The generation of primordial gravitational waves is investigated within the hybrid quintessential inflationary model. Using the method of continuous Bogoliubov coefficients, we calculate the full gravitational-wave energy spectrum. The post-inflationary kination period, characteristic of quintessential inflationary models, leaves a clear signature on the spectrum, namely, a sharp rise of the gravitational-wave spectral energy density Ω GW at high frequencies. For appropriate values of the parameters of the model, Ω GW can be as high as 10 -12 in the MHz-GHz range of frequencies.
Standard Model mass spectrum in inflationary universe
Energy Technology Data Exchange (ETDEWEB)
Chen, Xingang [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics,60 Garden Street, Cambridge, MA 02138 (United States); Wang, Yi [Department of Physics, The Hong Kong University of Science and Technology,Clear Water Bay, Kowloon, Hong Kong (China); Xianyu, Zhong-Zhi [Center of Mathematical Sciences and Applications, Harvard University,20 Garden Street, Cambridge, MA 02138 (United States)
2017-04-11
We work out the Standard Model (SM) mass spectrum during inflation with quantum corrections, and explore its observable consequences in the squeezed limit of non-Gaussianity. Both non-Higgs and Higgs inflation models are studied in detail. We also illustrate how some inflationary loop diagrams can be computed neatly by Wick-rotating the inflation background to Euclidean signature and by dimensional regularization.
A bulk viscosity driven inflationary model
International Nuclear Information System (INIS)
Waga, I.; Falcao, R.C.; Chanda, R.
1985-01-01
Bulk viscosity associated with the production of heavy particles during the GUT phase transition can lead to exponential or 'generalized' inflation. The condition of inflation proposed is independent of the details of the phase transition and remains unaltered in presence of a cosmological constant. Such mechanism avoids the extreme supercooling and reheating needed in the usual inflationary models. The standard baryongenesis mechanism can be maintained. (Author) [pt
A cosmological problem for maximally symmetric supergravity
International Nuclear Information System (INIS)
German, G.; Ross, G.G.
1986-01-01
Under very general considerations it is shown that inflationary models of the universe based on maximally symmetric supergravity with flat potentials are unable to resolve the cosmological energy density (Polonyi) problem. (orig.)
Constraining supergravity models from gluino production
International Nuclear Information System (INIS)
Barbieri, R.; Gamberini, G.; Giudice, G.F.; Ridolfi, G.
1988-01-01
The branching ratios for gluino decays g tilde → qanti qΧ, g tilde → gΧ into a stable undetected neutralino are computed as functions of the relevant parameters of the underlying supergravity theory. A simple way of constraining supergravity models from gluino production emerges. The effectiveness of hadronic versus e + e - colliders in the search for supersymmetry can be directly compared. (orig.)
Consistency of the tachyon warm inflationary universe models
International Nuclear Information System (INIS)
Zhang, Xiao-Min; Zhu, Jian-Yang
2014-01-01
This study concerns the consistency of the tachyon warm inflationary models. A linear stability analysis is performed to find the slow-roll conditions, characterized by the potential slow-roll (PSR) parameters, for the existence of a tachyon warm inflationary attractor in the system. The PSR parameters in the tachyon warm inflationary models are redefined. Two cases, an exponential potential and an inverse power-law potential, are studied, when the dissipative coefficient Γ = Γ 0 and Γ = Γ(φ), respectively. A crucial condition is obtained for a tachyon warm inflationary model characterized by the Hubble slow-roll (HSR) parameter ε H , and the condition is extendable to some other inflationary models as well. A proper number of e-folds is obtained in both cases of the tachyon warm inflation, in contrast to existing works. It is also found that a constant dissipative coefficient (Γ = Γ 0 ) is usually not a suitable assumption for a warm inflationary model
On the Predictiveness of Single-Field Inflationary Models
Burgess, C.P.; Trott, Michael
2014-01-01
We re-examine the predictiveness of single-field inflationary models and discuss how an unknown UV completion can complicate determining inflationary model parameters from observations, even from precision measurements. Besides the usual naturalness issues associated with having a shallow inflationary potential, we describe another issue for inflation, namely, unknown UV physics modifies the running of Standard Model (SM) parameters and thereby introduces uncertainty into the potential inflationary predictions. We illustrate this point using the minimal Higgs Inflationary scenario, which is arguably the most predictive single-field model on the market, because its predictions for $A_s$, $r$ and $n_s$ are made using only one new free parameter beyond those measured in particle physics experiments, and run up to the inflationary regime. We find that this issue can already have observable effects. At the same time, this UV-parameter dependence in the Renormalization Group allows Higgs Inflation to occur (in prin...
Inflationary gravitational waves in collapse scheme models
Energy Technology Data Exchange (ETDEWEB)
Mariani, Mauro, E-mail: mariani@carina.fcaglp.unlp.edu.ar [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, 1900 La Plata (Argentina); Bengochea, Gabriel R., E-mail: gabriel@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (IAFE), UBA-CONICET, CC 67, Suc. 28, 1428 Buenos Aires (Argentina); León, Gabriel, E-mail: gleon@df.uba.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria – Pab. I, 1428 Buenos Aires (Argentina)
2016-01-10
The inflationary paradigm is an important cornerstone of the concordance cosmological model. However, standard inflation cannot fully address the transition from an early homogeneous and isotropic stage, to another one lacking such symmetries corresponding to our present universe. In previous works, a self-induced collapse of the wave function has been suggested as the missing ingredient of inflation. Most of the analysis regarding the collapse hypothesis has been solely focused on the characteristics of the spectrum associated to scalar perturbations, and within a semiclassical gravity framework. In this Letter, working in terms of a joint metric-matter quantization for inflation, we calculate, for the first time, the tensor power spectrum and the tensor-to-scalar ratio corresponding to the amplitude of primordial gravitational waves resulting from considering a generic self-induced collapse.
On the topology of the inflaton field in minimal supergravity models
Energy Technology Data Exchange (ETDEWEB)
Ferrara, Sergio [Physics Department, Theory Unit, CERN,CH 1211, Geneva 23 (Switzerland); INFN - Laboratori Nazionali di Frascati,Via Enrico Fermi 40, I-00044, Frascati (Italy); Department of Physics and Astronomy, University of California,Los Angeles, CA 90095-1547 (United States); Fré, Pietro [Dipartimento di Fisica, Università di Torino, INFN - Sezione di Torino,via P. Giuria 1, I-10125 Torino (Italy); Sorin, Alexander S. [Bogoliubov Laboratory of Theoretical Physics,and Veksler and Baldin Laboratory of High Energy Physics,Joint Institute for Nuclear Research,141980 Dubna, Moscow Region (Russian Federation)
2014-04-14
We consider global issues in minimal supergravity models where a single field inflaton potential emerges. In a particular case we reproduce the Starobinsky model and its description dual to a certain formulation of R+R{sup 2} supergravity. For definiteness we confine our analysis to spaces at constant curvature, either vanishing or negative. Five distinct models arise, two flat models with respectively a quadratic and a quartic potential and three based on the ((SU(1,1))/(U(1))) space where its distinct isometries, elliptic, hyperbolic and parabolic are gauged. Fayet-Iliopoulos terms are introduced in a geometric way and they turn out to be a crucial ingredient in order to describe the de Sitter inflationary phase of the Starobinsky model.
On the topology of the inflaton field in minimal supergravity models
Ferrara, Sergio; Fré, Pietro; Sorin, Alexander S.
2014-04-01
We consider global issues in minimal supergravity models where a single field inflaton potential emerges. In a particular case we reproduce the Starobinsky model and its description dual to a certain formulation of R + R 2 supergravity. For definiteness we confine our analysis to spaces at constant curvature, either vanishing or negative. Five distinct models arise, two flat models with respectively a quadratic and a quartic potential and three based on the space where its distinct isometries, elliptic, hyperbolic and parabolic are gauged. Fayet-Iliopoulos terms are introduced in a geometric way and they turn out to be a crucial ingredient in order to describe the de Sitter inflationary phase of the Starobinsky model.
On the Topology of the Inflaton Field in Minimal Supergravity Models
Ferrara, Sergio; Sorin, Alexander S
2014-01-01
We consider global issues in minimal supergravity models where a single field inflaton potential emerges. In a particular case we reproduce the Starobinsky model and its description dual to a certain formulation of R+R^2 supergravity. For definiteness we confine our analysis to spaces at constant curvature, either vanishing or negative. Five distinct models arise, two flat models with respectively a quadratic and a quartic potential and three based on the SU(1,1)/U(1) space where its distinct isometries, elliptic, hyperbolic and parabolic are gauged. Fayet-Iliopoulos terms are introduced in a geometric way and they turn out to be a crucial ingredient in order to describe the de Sitter inflationary phase of the Starobinsky model.
Properties of Nilpotent Supergravity
Dudas, E.; Kehagias, A.; Sagnotti, A.
2015-09-30
We construct Supergravity models where the goldstino multiplet has a gravitational origin, being dual to the chiral curvature superfield. Supersymmetry is nonlinearly realized due to a nilpotent constraint, while the goldstino arises from $\\gamma$-traces of the gauge-invariant gravitino field strength. After duality transformations one recovers, as expected, the standard Volkov-Akulov Lagrangian coupled to Supergravity, but the gravitational origin of the goldstino multiplet restricts the available types of matter couplings. We also construct explicitly some inflationary models of this type, which contain both the inflaton and the nilpotent superfield.
Properties of nilpotent supergravity
Energy Technology Data Exchange (ETDEWEB)
Dudas, E. [Centre de Physique Théorique, École Polytéchnique,F-91128 Palaiseau (France); Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany); Ferrara, S. [Th-Ph Department, CERN,CH-1211 Geneva 23 (Switzerland); INFN - Laboratori Nazionali di Frascati,Via Enrico Fermi 40, 00044 Frascati (Italy); Department of Physics and Astronomy, University of California,Los Angeles, CA 90095-1547 (United States); Kehagias, A. [Th-Ph Department, CERN,CH-1211 Geneva 23 (Switzerland); Physics Division, National Technical University of Athens,15780 Zografou, Athens (Greece); Sagnotti, A. [Th-Ph Department, CERN,CH-1211 Geneva 23 (Switzerland); Scuola Normale Superiore and INFN,Piazza dei Cavalieri 7, 56126 Pisa (Italy)
2015-09-30
We construct supergravity models where the goldstino multiplet has a gravitational origin, being dual to the chiral curvature superfield. Supersymmetry is nonlinearly realized due to a nilpotent constraint, while the goldstino arises from γ-traces of the gauge-invariant gravitino field strength. After duality transformations one recovers, as expected, the standard Volkov-Akulov Lagrangian coupled to Supergravity, but the gravitational origin of the goldstino multiplet restricts the available types of matter couplings. We also construct explicitly some inflationary models of this type, which contain both the inflaton and the nilpotent superfield.
Inflationary models with non-minimally derivative coupling
International Nuclear Information System (INIS)
Yang, Nan; Fei, Qin; Gong, Yungui; Gao, Qing
2016-01-01
We derive the general formulae for the scalar and tensor spectral tilts to the second order for the inflationary models with non-minimally derivative coupling without taking the high friction limit. The non-minimally kinetic coupling to Einstein tensor brings the energy scale in the inflationary models down to be sub-Planckian. In the high friction limit, the Lyth bound is modified with an extra suppression factor, so that the field excursion of the inflaton is sub-Planckian. The inflationary models with non-minimally derivative coupling are more consistent with observations in the high friction limit. In particular, with the help of the non-minimally derivative coupling, the quartic power law potential is consistent with the observational constraint at 95% CL. (paper)
Supersymmetry, supergravity and superstring models
International Nuclear Information System (INIS)
Ross, G.G.
1987-01-01
The authors discuss the structure of models with a low-energy N=1 supersymmetry. This is extended to locally supersymmetric theories and to the models resulting if physics at the Planck scale is described by the superstring. The possible new light gauge and chiral supermultiplet structures are analysed and a specific model leading to the standard SU(3) x SU(2) x U(1) model is presented. Phenomenological implications of such models are discussed
Scrutinizing supergravity models through neutrino telescopes
Gandhi, R; Nanopoulos, Dimitri V; Yuan, K; Zichichi, Antonino; Gandhi, Raj; Lopez, Jorge L.; Yuan, Kajia
1994-01-01
Galactic halo neutralinos ($\\chi$) captured by the Sun or Earth produce high-energy neutrinos as end-products of various annihilation modes. These neutrinos can travel from the Sun or Earth cores to the neighborhood of underground detectors (``neutrino telescopes") where they can interact and produce upwardly-moving muons. We compute these muon fluxes in the context of the minimal $SU(5)$ supergravity model, and the no-scale and dilaton $SU(5)\\times U(1)$ supergravity models. At present, with the Kamiokande 90\\% C.L. upper limits on the flux, only a small fraction of the parameter space of the $SU(5)\\times U(1)$ models is accessible for $m_\\chi\\sim m_{\\rm Fe}$, which in turn implies constraints for the lightest chargino mass around 100 GeV for a range of $\\tan\\beta$ values. We also delineate the regions of parameter space that would be accessible with the improvements of experimental sensitivity expected in the near future at Gran Sasso, Super-Kamiokande, and other facilities such as DUMAND and AMANDA, curren...
Designing and testing inflationary models with Bayesian networks
Energy Technology Data Exchange (ETDEWEB)
Price, Layne C. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Physics; Auckland Univ. (New Zealand). Dept. of Physics; Peiris, Hiranya V. [Univ. College London (United Kingdom). Dept. of Physics and Astronomy; Frazer, Jonathan [DESY Hamburg (Germany). Theory Group; Univ. of the Basque Country, Bilbao (Spain). Dept. of Theoretical Physics; Basque Foundation for Science, Bilbao (Spain). IKERBASQUE; Easther, Richard [Auckland Univ. (New Zealand). Dept. of Physics
2015-11-15
Even simple inflationary scenarios have many free parameters. Beyond the variables appearing in the inflationary action, these include dynamical initial conditions, the number of fields, and couplings to other sectors. These quantities are often ignored but cosmological observables can depend on the unknown parameters. We use Bayesian networks to account for a large set of inflationary parameters, deriving generative models for the primordial spectra that are conditioned on a hierarchical set of prior probabilities describing the initial conditions, reheating physics, and other free parameters. We use N{sub f}-quadratic inflation as an illustrative example, finding that the number of e-folds N{sub *} between horizon exit for the pivot scale and the end of inflation is typically the most important parameter, even when the number of fields, their masses and initial conditions are unknown, along with possible conditional dependencies between these parameters.
Designing and testing inflationary models with Bayesian networks
Energy Technology Data Exchange (ETDEWEB)
Price, Layne C. [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Peiris, Hiranya V. [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Frazer, Jonathan [Deutsches Elektronen-Synchrotron DESY, Theory Group, 22603 Hamburg (Germany); Easther, Richard, E-mail: laynep@andrew.cmu.edu, E-mail: h.peiris@ucl.ac.uk, E-mail: jonathan.frazer@desy.de, E-mail: r.easther@auckland.ac.nz [Department of Physics, University of Auckland, Private Bag 92019, Auckland (New Zealand)
2016-02-01
Even simple inflationary scenarios have many free parameters. Beyond the variables appearing in the inflationary action, these include dynamical initial conditions, the number of fields, and couplings to other sectors. These quantities are often ignored but cosmological observables can depend on the unknown parameters. We use Bayesian networks to account for a large set of inflationary parameters, deriving generative models for the primordial spectra that are conditioned on a hierarchical set of prior probabilities describing the initial conditions, reheating physics, and other free parameters. We use N{sub f}-quadratic inflation as an illustrative example, finding that the number of e-folds N{sub *} between horizon exit for the pivot scale and the end of inflation is typically the most important parameter, even when the number of fields, their masses and initial conditions are unknown, along with possible conditional dependencies between these parameters.
Designing and testing inflationary models with Bayesian networks
International Nuclear Information System (INIS)
Price, Layne C.; Auckland Univ.; Peiris, Hiranya V.; Frazer, Jonathan; Univ. of the Basque Country, Bilbao; Basque Foundation for Science, Bilbao; Easther, Richard
2015-11-01
Even simple inflationary scenarios have many free parameters. Beyond the variables appearing in the inflationary action, these include dynamical initial conditions, the number of fields, and couplings to other sectors. These quantities are often ignored but cosmological observables can depend on the unknown parameters. We use Bayesian networks to account for a large set of inflationary parameters, deriving generative models for the primordial spectra that are conditioned on a hierarchical set of prior probabilities describing the initial conditions, reheating physics, and other free parameters. We use N f -quadratic inflation as an illustrative example, finding that the number of e-folds N * between horizon exit for the pivot scale and the end of inflation is typically the most important parameter, even when the number of fields, their masses and initial conditions are unknown, along with possible conditional dependencies between these parameters.
Bianchi Type-II inflationary models with constant deceleration ...
Indian Academy of Sciences (India)
ginning of the 1980s, nowadays receives a great deal of attention. Guth [1] proposed inflationary model in the context of grand unified theory (GUT), which has been accepted soon as the ..... where m1(> 0) is a constant of integration and n = 3. .... interesting feature of the present solution is that it is possible to exit from expo-.
Inflationary universe models and the formation of structure
International Nuclear Information System (INIS)
Brandenberger, R.H.
1987-01-01
The main features of inflationary universe models are briefly reviewed. Inflation provides a mechanism which produces energy density fluctuations on cosmological scales. In the original models, it was not possible to obtain the correct magnitude of these fluctuations without fine tuning the particle physics models. Two mechanisms, chaotic inflation, and a dynamical relaxation process are discussed by which inflation may be realized in models which give the right magnitude of fluctuations. 22 references
Standard model fermions and N=8 supergravity
Energy Technology Data Exchange (ETDEWEB)
Nicolai, Hermann [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Muehlenberg 1, Potsdam-Golm (Germany)
2016-07-01
In a scheme originally proposed by Gell-Mann, and subsequently shown to be realized at the SU(3) x U(1) stationary point of maximal gauged SO(8) supergravity, the 48 spin-1/2 fermions of the theory remaining after the removal of eight Goldstinos can be identified with the 48 quarks and leptons (including right-chiral neutrinos) of the Standard model, provided one identifies the residual SU(3) with the diagonal subgroup of the color group SU(3){sub c} and a family symmetry SU(3){sub f}. However, there remained a systematic mismatch in the electric charges by a spurion charge of ± 1/6. We here identify the ''missing'' U(1) that rectifies this mismatch, and that takes a surprisingly simple, though unexpected form, and show how it is related to the conjectured R symmetry K(E10) of M Theory.
CMB constraints on β-exponential inflationary models
Santos, M. A.; Benetti, M.; Alcaniz, J. S.; Brito, F. A.; Silva, R.
2018-03-01
We analyze a class of generalized inflationary models proposed in ref. [1], known as β-exponential inflation. We show that this kind of potential can arise in the context of brane cosmology, where the field describing the size of the extra-dimension is interpreted as the inflaton. We discuss the observational viability of this class of model in light of the latest Cosmic Microwave Background (CMB) data from the Planck Collaboration through a Bayesian analysis, and impose tight constraints on the model parameters. We find that the CMB data alone prefer weakly the minimal standard model (ΛCDM) over the β-exponential inflation. However, when current local measurements of the Hubble parameter, H0, are considered, the β-inflation model is moderately preferred over the ΛCDM cosmology, making the study of this class of inflationary models interesting in the context of the current H0 tension.
The electroweak phase transition in minimal supergravity models
Nanopoulos, Dimitri V
1994-01-01
We have explored the electroweak phase transition in minimal supergravity models by extending previous analysis of the one-loop Higgs potential to include finite temperature effects. Minimal supergravity is characterized by two higgs doublets at the electroweak scale, gauge coupling unification, and universal soft-SUSY breaking at the unification scale. We have searched for the allowed parameter space that avoids washout of baryon number via unsuppressed anomalous Electroweak sphaleron processes after the phase transition. This requirement imposes strong constraints on the Higgs sector. With respect to weak scale baryogenesis, we find that the generic MSSM is {\\it not} phenomenologically acceptable, and show that the additional experimental and consistency constraints of minimal supergravity restricts the mass of the lightest CP-even Higgs even further to $m_h\\lsim 32\\GeV$ (at one loop), also in conflict with experiment. Thus, if supergravity is to allow for baryogenesis via any other mechanism above the weak...
Low reheating temperatures in monomial and binomial inflationary models
International Nuclear Information System (INIS)
Rehagen, Thomas; Gelmini, Graciela B.
2015-01-01
We investigate the allowed range of reheating temperature values in light of the Planck 2015 results and the recent joint analysis of Cosmic Microwave Background (CMB) data from the BICEP2/Keck Array and Planck experiments, using monomial and binomial inflationary potentials. While the well studied ϕ 2 inflationary potential is no longer favored by current CMB data, as well as ϕ p with p>2, a ϕ 1 potential and canonical reheating (w re =0) provide a good fit to the CMB measurements. In this last case, we find that the Planck 2015 68% confidence limit upper bound on the spectral index, n s , implies an upper bound on the reheating temperature of T re ≲6×10 10 GeV, and excludes instantaneous reheating. The low reheating temperatures allowed by this model open the possibility that dark matter could be produced during the reheating period instead of when the Universe is radiation dominated, which could lead to very different predictions for the relic density and momentum distribution of WIMPs, sterile neutrinos, and axions. We also study binomial inflationary potentials and show the effects of a small departure from a ϕ 1 potential. We find that as a subdominant ϕ 2 term in the potential increases, first instantaneous reheating becomes allowed, and then the lowest possible reheating temperature of T re =4 MeV is excluded by the Planck 2015 68% confidence limit
Topics in inflationary cosmologies
International Nuclear Information System (INIS)
Mahajan, S.
1986-04-01
Several aspects of inflationary cosmologies are discussed. An introduction to the standard hot big bang cosmological model is reviewed, and some of the problems associated with it are presented. A short review of the proposals for solving the cosmological conundrums of the big bang model is presented. Old and the new inflationary scenarios are discussed and shown to be unacceptable. Some alternative scenarios especially those using supersymmetry are reviewed briefly. A study is given of inflationary models where the same set of fields that breaks supersymmetry is also responsible for inflation. In these models, the scale of supersymmetry breaking is related to the slope of the potential near the origin and can thus be kept low. It is found that a supersymmetry breaking scale of the order of the weak breaking scale. The cosmology obtained from the simplest of such models is discussed in detail and it is shown that there are no particular problems except a low reheating temperature and a violation of the thermal constraint. A possible solution to the thermal constraint problem is given by introducing a second field, and the role played by this second field in the scenario is discussed. An alternative mechanism for the generation of baryon number within the framework of supergravity inflationary models is studied using the gravitational couplings of the heavy fields with the hidden sector (the sector which breaks supersymmetry). This mechanism is applied to two specific models - one with and one without supersymmetry breaking. The baryon to entropy ratio is found to be dependent on parameters which are model dependent. Finally, the effect of direct coupling between the two sectors on results is related, 88 refs., 6 figs
Simple inflationary quintessential model. II. Power law potentials
de Haro, Jaume; Amorós, Jaume; Pan, Supriya
2016-09-01
The present work is a sequel of our previous work [Phys. Rev. D 93, 084018 (2016)] which depicted a simple version of an inflationary quintessential model whose inflationary stage was described by a Higgs-type potential and the quintessential phase was responsible due to an exponential potential. Additionally, the model predicted a nonsingular universe in past which was geodesically past incomplete. Further, it was also found that the model is in agreement with the Planck 2013 data when running is allowed. But, this model provides a theoretical value of the running which is far smaller than the central value of the best fit in ns , r , αs≡d ns/d l n k parameter space where ns, r , αs respectively denote the spectral index, tensor-to-scalar ratio and the running of the spectral index associated with any inflationary model, and consequently to analyze the viability of the model one has to focus in the two-dimensional marginalized confidence level in the allowed domain of the plane (ns,r ) without taking into account the running. Unfortunately, such analysis shows that this model does not pass this test. However, in this sequel we propose a family of models runs by a single parameter α ∈[0 ,1 ] which proposes another "inflationary quintessential model" where the inflation and the quintessence regimes are respectively described by a power law potential and a cosmological constant. The model is also nonsingular although geodesically past incomplete as in the cited model. Moreover, the present one is found to be more simple compared to the previous model and it is in excellent agreement with the observational data. In fact, we note that, unlike the previous model, a large number of the models of this family with α ∈[0 ,1/2 ) match with both Planck 2013 and Planck 2015 data without allowing the running. Thus, the properties in the current family of models compared to its past companion justify its need for a better cosmological model with the successive
A No-Scale Inflationary Model to Fit Them All
Ellis, John; Nanopoulos, Dimitri; Olive, Keith
2014-01-01
The magnitude of B-mode polarization in the cosmic microwave background as measured by BICEP2 favours models of chaotic inflation with a quadratic $m^2 \\phi^2/2$ potential, whereas data from the Planck satellite favour a small value of the tensor-to-scalar perturbation ratio $r$ that is highly consistent with the Starobinsky $R + R^2$ model. Reality may lie somewhere between these two scenarios. In this paper we propose a minimal two-field no-scale supergravity model that interpolates between quadratic and Starobinsky-like inflation as limiting cases, while retaining the successful prediction $n_s \\simeq 0.96$.
Emergence of inflationary perturbations in the CSL model
Energy Technology Data Exchange (ETDEWEB)
Leon, Gabriel [Universidad de Buenos Aires, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Bengochea, Gabriel R. [Instituto de Astronomia y Fisica del Espacio (IAFE), UBA-CONICET, Buenos Aires (Argentina)
2016-01-15
The inflationary paradigm is the most successful model that explains the observed spectrum of primordial perturbations. However, the precise emergence of such inhomogeneities and the quantum-to-classical transition of the perturbations has not yet reached a consensus among the community. The continuous spontaneous localization model (CSL), in the cosmological context, might be used to provide a solution to the mentioned issues by considering a dynamical reduction of the wave function. The CSL model has been applied to the inflationary universe before and different conclusions have been obtained. In this letter, we use a different approach to implement the CSL model during inflation. In particular, in addition to accounting for the quantum-to-classical transition, we use the CSL model to generate the primordial perturbations, that is, the dynamical evolution provided by the CSL model is responsible for the transition from a homogeneous and isotropic initial state to a final one lacking such symmetries. Our approach leads to results that can be clearly distinguished from preceding works. Specifically, the scalar and tensor power spectra are not time-dependent, and one retains the amplification mechanism of the CSL model. Moreover, our framework depends only on one parameter (the CSL parameter) and its value is consistent with cosmological and laboratory observations. (orig.)
Consistent classical supergravity theories
International Nuclear Information System (INIS)
Muller, M.
1989-01-01
This book offers a presentation of both conformal and Poincare supergravity. The consistent four-dimensional supergravity theories are classified. The formulae needed for further modelling are included
Power-law and intermediate inflationary models in f(T)-gravity
Energy Technology Data Exchange (ETDEWEB)
Rezazadeh, K. [Department of Physics, University of Kurdistan,Pasdaran St., Sanandaj (Iran, Islamic Republic of); Abdolmaleki, A. [Research Institute for Astronomy Astrophysics of Maragha (RIAAM),P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Karami, K. [Department of Physics, University of Kurdistan,Pasdaran St., Sanandaj (Iran, Islamic Republic of)
2016-01-21
We study inflation in the framework of f(T)-gravity in the presence of a canonical scalar field. After reviewing the basic equations governing the background cosmology in f(T)-gravity, we turn to study the cosmological perturbations and obtain the evolutionary equations for the scalar and tensor perturbations. Solving those equations, we find the power spectra for the scalar and tensor perturbations. Then, we consider a power-law f(T) function and investigate the inflationary models with the power-law and intermediate scale factors. We see that in contrast with the standard inflationary scenario based on the Einstein gravity, the power-law and intermediate inflationary models in f(T)-gravity can be compatible with the observational results of Planck 2015 at 68% CL. We find that in our f(T) setting, the potentials responsible for the both power-law and intermediate inflationary models have the power-law form V(ϕ)∝ϕ{sup m} but the power m is different for them. Therefore, we can refine some of power-law inflationary potentials in the framework of f(T)-gravity while they are disfavored by the observational data in the standard inflationary scenario. Interestingly enough, is that the self-interacting quartic potential V(ϕ)∝ϕ{sup 4} which has special reheating properties, can be consistent with the Planck 2015 data in our f(T) scenario while it is ruled out in the standard inflationary scenario.
Power-law and intermediate inflationary models in f(T)-gravity
International Nuclear Information System (INIS)
Rezazadeh, K.; Abdolmaleki, A.; Karami, K.
2016-01-01
We study inflation in the framework of f(T)-gravity in the presence of a canonical scalar field. After reviewing the basic equations governing the background cosmology in f(T)-gravity, we turn to study the cosmological perturbations and obtain the evolutionary equations for the scalar and tensor perturbations. Solving those equations, we find the power spectra for the scalar and tensor perturbations. Then, we consider a power-law f(T) function and investigate the inflationary models with the power-law and intermediate scale factors. We see that in contrast with the standard inflationary scenario based on the Einstein gravity, the power-law and intermediate inflationary models in f(T)-gravity can be compatible with the observational results of Planck 2015 at 68% CL. We find that in our f(T) setting, the potentials responsible for the both power-law and intermediate inflationary models have the power-law form V(ϕ)∝ϕ m but the power m is different for them. Therefore, we can refine some of power-law inflationary potentials in the framework of f(T)-gravity while they are disfavored by the observational data in the standard inflationary scenario. Interestingly enough, is that the self-interacting quartic potential V(ϕ)∝ϕ 4 which has special reheating properties, can be consistent with the Planck 2015 data in our f(T) scenario while it is ruled out in the standard inflationary scenario.
Top-down approach to unified supergravity models
International Nuclear Information System (INIS)
Hempfling, R.
1994-03-01
We introduce a new approach for studying unified supergravity models. In this approach all the parameters of the grand unified theory (GUT) are fixed by imposing the corresponding number of low energy observables. This determines the remaining particle spectrum whose dependence on the low energy observables can now be investigated. We also include some SUSY threshold corrections that have previously been neglected. In particular the SUSY threshold corrections to the fermion masses can have a significant impact on the Yukawa coupling unification. (orig.)
'Semi-realistic'F-term inflation model building in supergravity
International Nuclear Information System (INIS)
Kain, Ben
2008-01-01
We describe methods for building 'semi-realistic' models of F-term inflation. By semi-realistic we mean that they are built in, and obey the requirements of, 'semi-realistic' particle physics models. The particle physics models are taken to be effective supergravity theories derived from orbifold compactifications of string theory, and their requirements are taken to be modular invariance, absence of mass terms and stabilization of moduli. We review the particle physics models, their requirements and tools and methods for building inflation models
Sneutrino driven GUT inflation in supergravity
International Nuclear Information System (INIS)
Gonzalo, Tomás E.; Heurtier, Lucien; Moursy, Ahmad
2017-01-01
In this paper, we embed the model of flipped GUT sneutrino inflation — in a flipped SU(5) or SO(10) set up — developed by Ellis et al. in a supergravity framework. The GUT symmetry is broken by a waterfall which could happen at early or late stage of the inflationary period. The full field dynamics is thus studied in detail and these two main inflationary configurations are exposed, whose cosmological predictions are both in agreement with recent astrophysical measurements. The model has an interesting feature where the inflaton has natural decay channels to the MSSM particles allowed by the GUT gauge symmetry. Hence it can account for the reheating after the inflationary epoch.
Sneutrino driven GUT inflation in supergravity
Gonzalo, Tomás E.; Heurtier, Lucien; Moursy, Ahmad
2017-06-01
In this paper, we embed the model of flipped GUT sneutrino inflation — in a flipped SU(5) or SO(10) set up — developed by Ellis et al. in a supergravity framework. The GUT symmetry is broken by a waterfall which could happen at early or late stage of the inflationary period. The full field dynamics is thus studied in detail and these two main inflationary configurations are exposed, whose cosmological predictions are both in agreement with recent astrophysical measurements. The model has an interesting feature where the inflaton has natural decay channels to the MSSM particles allowed by the GUT gauge symmetry. Hence it can account for the reheating after the inflationary epoch.
General f(R and conformal inflation from minimal supergravity plus matter
Directory of Open Access Journals (Sweden)
Horatiu Nastase
2016-02-01
Full Text Available We embed general f(R inflationary models in minimal supergravity plus matter, a single chiral superfield Φ, with or without another superfield S, via a Jordan frame Einstein+scalar description. In particular, inflationary models like a generalized Starobinsky one are analyzed and constraints on them are found. We also embed the related models of conformal inflation, also described as Jordan frame Einstein+scalar models, in particular the conformal inflation from the Higgs model, and analyze the inflationary constraints on them.
Chamseddine, A H; Nath, Pran; Chamseddine, Ali H.; Nath, Pran
2001-01-01
A review is given of the historical developments of 1982 that lead to the supergravity unified model (SUGRA)with gravity mediated breaking of supersymmetry. Further developments and applications of the model in the period 1982-85 are also discussed. The supergravity unified model and its minimal version (mSUGRA) are currently among the leading candidates for physics beyond the Standard Model. A brief note on the developments from the present vantage point is included.
Reconstruction of the Scalar Field Potential in Inflationary Models with a Gauss-Bonnet term
Koh, Seoktae; Lee, Bum-Hoon; Tumurtushaa, Gansukh
2017-06-01
We consider inflationary models with a Gauss-Bonnet term to reconstruct the scalar-field potentials and the Gauss-Bonnet coupling functions. Both expressions are derived from the observationally favored configurations of ns and r . Our result implies that, for the reconstructed potentials and coupling functions, the blue tilt of inflationary tensor fluctuations can be realized. To achieve a blue tilt for the inflationary tensor fluctuations, a scalar field must climb up its potential before rolling down. We further investigate the properties of propagation of the perturbation modes in Friedmann-Robertson-Walker spacetime. For the reconstructed configurations that give rise to the blue tilt for the inflationary tensor fluctuations, we show that the ghosts and instabilities are absent with the superluminal propagation speeds for the scalar perturbation modes, whereas the propagation speeds of the tensor perturbations are subluminal.
Simple inflationary models in Gauss–Bonnet brane-world cosmology
International Nuclear Information System (INIS)
Okada, Nobuchika; Okada, Satomi
2016-01-01
In light of the recent Planck 2015 results for the measurement of the cosmic microwave background (CMB) anisotropy, we study simple inflationary models in the context of the Gauss–Bonnet (GB) brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index ( n s ) and the tensor-to-scalar ratio ( r ) from those obtained in the standard cosmology. In particular, the predicted r values in the inflationary models favored by the Planck 2015 results are suppressed due to the GB brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall–Sundrum brane-world cosmology, where the r values are enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the GB brane-world cosmology can be tested by more precise measurements of n s and future observations of the CMB B -mode polarization. (paper)
Tribrid Inflation in Supergravity
International Nuclear Information System (INIS)
Antusch, Stefan; Dutta, Koushik; Kostka, Philipp M.
2010-01-01
We propose a novel class of F-term hybrid inflation models in supergravity (SUGRA) where the η-problem is resolved using either a Heisenberg symmetry or a shift symmetry of the Kaehler potential. In addition to the inflaton and the waterfall field, this class (referred to as tribrid inflation) contains a third 'driving' field which contributes the large vacuum energy during inflation by its F-term. In contrast to the 'standard' hybrid scenario, it has several attractive features due to the property of vanishing inflationary superpotential (W inf = 0) during inflation. While the symmetries of the Kaehler potential ensure a flat inflaton potential at tree-level, quantum corrections induced by symmetry breaking terms in the superpotential generate a slope of the potential and lead to a spectral tilt consistent with recent WMAP observations.
Tribrid Inflation in Supergravity
Antusch, Stefan; Dutta, Koushik; Kostka, Philipp M.
We propose a novel class of F-term hybrid inflation models in supergravity (SUGRA) where the η-problem is resolved using either a Heisenberg symmetry or a shift symmetry of the Kähler potential. In addition to the inflaton and the waterfall field, this class (referred to as tribrid inflation) contains a third "driving" field which contributes the large vacuum energy during inflation by its F-term. In contrast to the "standard" hybrid scenario, it has several attractive features due to the property of vanishing inflationary superpotential (Winf = 0) during inflation. Quantum corrections induced by symmetry breaking terms in the superpotential generate a slope of the potential and lead to a spectral tilt consistent with recent WMAP observations.
BOOK REVIEW: Supergravity Supergravity
Gregory, Ruth
2013-02-01
Supergravity is an essential ingredient in so many areas of ultra high energy physics, yet it is rarely taught systematically, even at the graduate level. Students most often have to learn along with applying, and must use the now classic older texts. For such core material, it is surprising that there are so few good texts on the subject. It is not necessarily that supergravity is so much more conceptually complex, rather that it is technical and therefore easy for a text to become dry, dense and rather indigestible. This book, written by two experts in the field, is therefore a breath of fresh air. It not only represents a comprehensive modern overview of the subject, but achieves this with clarity, accessibility, and even humour! To paraphrase the authors, if you are not impressed by this book, you should put it down and watch television instead. It starts by reviewing, or overviewing, aspects of field theory, basic supersymmetry and gravity that will be needed for the rest of the book. This first third or so of the book is very condensed, and will not be easy to follow for those who have not encountered the material before. However, the authors acknowledge this and give plenty of suggestions for more pedagogical texts in the relevant areas, thus it does not feel overly brief. The middle section deals with the construction of supergravity, starting with basic N = 1 supergravity in 4 and 11 dimensions and gradually extending the discussion to include matter multiplets. This part of the book systematically builds up understanding and construction of models, before moving on to superconformal methods. The purpose is not to cover all supergravity theories, but to focus on a few examples in detail, and to give sufficient expertise and information for the reader to be able to deal with any other models they might need. The final part of the book deals with applications, and includes two chapters on applications in adS/CFT, which will be of most interest to new
Warm intermediate inflationary Universe model in the presence of a generalized Chaplygin gas
Energy Technology Data Exchange (ETDEWEB)
Herrera, Ramon [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Videla, Nelson [Universidad de Chile, Departamento de Fisica, FCFM, Santiago (Chile); Olivares, Marco [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile)
2016-01-15
A warm intermediate inflationary model in the context of generalized Chaplygin gas is investigated. We study this model in the weak and strong dissipative regimes, considering a generalized form of the dissipative coefficient Γ = Γ(T,φ), and we describe the inflationary dynamics in the slow-roll approximation. We find constraints on the parameters in our model considering the Planck 2015 data, together with the condition for warm inflation T > H, and the conditions for the weak and strong dissipative regimes. (orig.)
Particle physics models of inflation in supergravity and grand unification
International Nuclear Information System (INIS)
Kostka, Philipp Manuel
2010-01-01
In the first part of this thesis, we study classes of hybrid and chaotic inflation models in four-dimensional N=1 supergravity. Therein, the η-problem can be resolved relying on fundamental symmetries in the Kaehler potential. Concretely, we investigate explicit realizations of superpotentials, in which the flatness of the inflaton potential is protected at tree level by a shift symmetry or a Heisenberg symmetry in the Kaehler potential. In the latter case, the associated modulus field can be stabilized during inflation by supergravity effects. In the context of hybrid inflation, a novel class of models, to which we refer as ''tribrid inflation,'' turns out to be particularly compatible with such symmetry solutions to the η-problem. Radiative corrections due to operators in the superpotential, which break the respective symmetry, generate the required small slope of the inflaton potential. Additional effective operators in the Kaehler potential can reduce the predicted spectral index so that it agrees with latest observational data. Within a model of chaotic inflation in supergravity with a quadratic potential, we apply the Heisenberg symmetry to allow for viable inflation with super-Planckian field values, while the associated modulus is stabilized. We show that radiative corrections are negligible in this context. In the second part, the tribrid inflation models are extended to realize gauge non-singlet inflation. This is applied to the matter sector of supersymmetric Grand Unified Theories based on the Pati-Salam gauge group. For the specific scenario in which the right-handed sneutrino is the inflaton, we study the scalar potential in a D-flat valley. We show that despite potentially dangerous two-loop corrections, the required flatness of the potential can be maintained. The reason for this is the strong suppression of gauge interactions of the inflaton field due to its symmetry breaking vacuum expectation value. In addition, the production of stable
Particle physics models of inflation in supergravity and grand unification
Energy Technology Data Exchange (ETDEWEB)
Kostka, Philipp Manuel
2010-12-03
In the first part of this thesis, we study classes of hybrid and chaotic inflation models in four-dimensional N=1 supergravity. Therein, the {eta}-problem can be resolved relying on fundamental symmetries in the Kaehler potential. Concretely, we investigate explicit realizations of superpotentials, in which the flatness of the inflaton potential is protected at tree level by a shift symmetry or a Heisenberg symmetry in the Kaehler potential. In the latter case, the associated modulus field can be stabilized during inflation by supergravity effects. In the context of hybrid inflation, a novel class of models, to which we refer as ''tribrid inflation,'' turns out to be particularly compatible with such symmetry solutions to the {eta}-problem. Radiative corrections due to operators in the superpotential, which break the respective symmetry, generate the required small slope of the inflaton potential. Additional effective operators in the Kaehler potential can reduce the predicted spectral index so that it agrees with latest observational data. Within a model of chaotic inflation in supergravity with a quadratic potential, we apply the Heisenberg symmetry to allow for viable inflation with super-Planckian field values, while the associated modulus is stabilized. We show that radiative corrections are negligible in this context. In the second part, the tribrid inflation models are extended to realize gauge non-singlet inflation. This is applied to the matter sector of supersymmetric Grand Unified Theories based on the Pati-Salam gauge group. For the specific scenario in which the right-handed sneutrino is the inflaton, we study the scalar potential in a D-flat valley. We show that despite potentially dangerous two-loop corrections, the required flatness of the potential can be maintained. The reason for this is the strong suppression of gauge interactions of the inflaton field due to its symmetry breaking vacuum expectation value. In addition, the
Effects of viscous pressure on warm inflationary generalized cosmic Chaplygin gas model
Energy Technology Data Exchange (ETDEWEB)
Sharif, M.; Saleem, Rabia, E-mail: msharif.math@pu.edu.pk, E-mail: rabiasaleem1988@yahoo.com [Department of Mathematics, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590 (Pakistan)
2014-12-01
This paper is devoted to study the effects of bulk viscous pressure on an inflationary generalized cosmic Chaplygin gas model using FRW background. The matter contents of the universe are assumed to be inflaton and imperfect fluid. We evaluate inflaton fields, potentials and entropy density for variable as well as constant dissipation and bulk viscous coefficients in weak as well as high dissipative regimes during intermediate era. In order to discuss inflationary perturbations, we evaluate entropy density, scalar (tensor) power spectra, their corresponding spectral indices, tensor-scalar ratio and running of spectral index in terms of inflaton which are constrained using recent Planck, WMAP7 and Bicep2 probes.
Effects of viscous pressure on warm inflationary generalized cosmic Chaplygin gas model
International Nuclear Information System (INIS)
Sharif, M.; Saleem, Rabia
2014-01-01
This paper is devoted to study the effects of bulk viscous pressure on an inflationary generalized cosmic Chaplygin gas model using FRW background. The matter contents of the universe are assumed to be inflaton and imperfect fluid. We evaluate inflaton fields, potentials and entropy density for variable as well as constant dissipation and bulk viscous coefficients in weak as well as high dissipative regimes during intermediate era. In order to discuss inflationary perturbations, we evaluate entropy density, scalar (tensor) power spectra, their corresponding spectral indices, tensor-scalar ratio and running of spectral index in terms of inflaton which are constrained using recent Planck, WMAP7 and Bicep2 probes
Two-Field Analysis of No-Scale Supergravity Inflation
Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A
2015-01-01
Since the building-blocks of supersymmetric models include chiral superfields containing pairs of effective scalar fields, a two-field approach is particularly appropriate for models of inflation based on supergravity. In this paper, we generalize the two-field analysis of the inflationary power spectrum to supergravity models with arbitrary K\\"ahler potential. We show how two-field effects in the context of no-scale supergravity can alter the model predictions for the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$, yielding results that interpolate between the Planck-friendly Starobinsky model and BICEP2-friendly predictions. In particular, we show that two-field effects in a chaotic no-scale inflation model with a quadratic potential are capable of reducing $r$ to very small values $\\ll 0.1$. We also calculate the non-Gaussianity measure $f_{\\rm NL}$, finding that is well below the current experimental sensitivity.
WMAP constraints on inflationary models with global defects
International Nuclear Information System (INIS)
Bevis, Neil; Hindmarsh, Mark; Kunz, Martin
2004-01-01
We use the cosmic microwave background angular power spectra to place upper limits on the degree to which global defects may have aided cosmic structure formation. We explore this under the inflationary paradigm, but with the addition of textures resulting from the breaking of a global O(4) symmetry during the early stages of the Universe. As a measure of their contribution, we use the fraction of the temperature power spectrum that is attributed to the defects at a multipole of 10. However, we find a parameter degeneracy enabling a fit to the first-year WMAP data to be made even with a significant defect fraction. This degeneracy involves the baryon fraction and the Hubble constant, plus the normalization and tilt of the primordial power spectrum. Hence, constraints on these cosmological parameters are weakened. Combining the WMAP data with a constraint on the physical baryon fraction from big bang nucleosynthesis calculations and high-redshift deuterium abundance limits the extent of the degeneracy and gives an upper bound on the defect fraction of 0.13 (95% confidence)
New phenomena in the standard no-scale supergravity model
Kelley, S; Nanopoulos, Dimitri V; Zichichi, Antonino; Kelley, S; Lopez, J L; Nanopoulos, D V; Zichichi, A
1994-01-01
We revisit the no-scale mechanism in the context of the simplest no-scale supergravity extension of the Standard Model. This model has the usual five-dimensional parameter space plus an additional parameter \\xi_{3/2}\\equiv m_{3/2}/m_{1/2}. We show how predictions of the model may be extracted over the whole parameter space. A necessary condition for the potential to be stable is {\\rm Str}{\\cal M}^4>0, which is satisfied if \\bf m_{3/2}\\lsim2 m_{\\tilde q}. Order of magnitude calculations reveal a no-lose theorem guaranteeing interesting and potentially observable new phenomena in the neutral scalar sector of the theory which would constitute a ``smoking gun'' of the no-scale mechanism. This new phenomenology is model-independent and divides into three scenarios, depending on the ratio of the weak scale to the vev at the minimum of the no-scale direction. We also calculate the residual vacuum energy at the unification scale (C_0\\, m^4_{3/2}), and find that in typical models one must require C_0>10. Such constrai...
Impacts of supersymmetric higher derivative terms on inflation models in supergravity
International Nuclear Information System (INIS)
Aoki, Shuntaro; Yamada, Yusuke
2015-01-01
We show the effects of supersymmetric higher derivative terms on inflation models in supergravity. The results show that such terms generically modify the effective kinetic coefficient of the inflaton during inflation if the cut off scale of the higher derivative operators is sufficiently small. In such a case, the η-problem in supergravity does not occur, and we find that the effective potential of the inflaton generically becomes a power type potential with a power smaller than two
Higher Curvature Supergravity, Supersymmetry Breaking and Inflation
Ferrara, Sergio
2017-01-01
In these lectures, after a short introduction to cosmology, we discuss the supergravity embedding of higher curvature models of inflation. The supergravity description of such models is presented for the two different formulations of minimal supergravity.
The present and future of the most favoured inflationary models after Planck 2015
Energy Technology Data Exchange (ETDEWEB)
Escudero, Miguel; Ramírez, Héctor; Boubekeur, Lotfi; Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de Valencia, Apartado de Correos 22085, E-46071 (Spain); Giusarma, Elena, E-mail: miguel.escudero@ific.uv.es, E-mail: hector.ramirez@ific.uv.es, E-mail: lboubekeur@usfq.edu.ec, E-mail: elena.giusarma@roma1.infn.it, E-mail: olga.mena@ific.uv.es [Physics Department and INFN, Università di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185, Rome (Italy)
2016-02-01
The value of the tensor-to-scalar ratio r in the region allowed by the latest Planck 2015 measurements can be associated to a large variety of inflationary models. We discuss here the potential of future Cosmic Microwave Background cosmological observations in disentangling among the possible theoretical scenarios allowed by our analyses of current Planck temperature and polarization data. Rather than focusing only on r, we focus as well on the running of the primordial power spectrum, α{sub s} and the running thereof, β{sub s}. If future cosmological measurements, as those from the COrE mission, confirm the current best-fit value for β{sub s} ∼> 10{sup −2} as the preferred one, it will be possible to rule-out the most favoured inflationary models.
Aspects of radiative electroweak breaking in supergravity models
International Nuclear Information System (INIS)
Kelley, S.; Lopez, J.L.; Nanopoulos, D.V.; Pois, H.; Yuan, K.
1993-01-01
We discuss several aspects of state-of-the-art calculations of radiative electroweak symmetry breaking in supergravity models. These models have a five-dimensional parameter space in contrast with the 21-dimensional one of the MSSM. We examine the Higgs one-loop effective potential V 1 =V 0 +ΔV, in particular how its renormalization-scale (Q) independence is affected by the approximation used to calculate ΔV and by the presence of a Higgs-field-independent term which makes V 1 (0)≠0. We show that the latter must be subtracted out to achieve Q-independence. We also discuss our own approach to the exploration of the five-dimensional parameter space and the fine-tuning constraints within this approach. We apply our methods to the determination of the allowed region in parameter space of two models which we argue to be the prototypes for conventional (SSM) and string (SISM) unified models. To this end we impose the electroweak breaking constraint by minimizing the one-loop effective potential and study the shifts in μ and B relative to the values obtained using the tree-level potential. These shifts are most significant for small values of μ and B, and induce corresponding shifts on the lightest μ- and/or B-dependent particle masses, i.e., those of the lightest stau, neutralino, chargino, and Higgs boson states. Finally, we discuss the predictions for the squark, slepton, and one-loop corrected Higgs boson masses. (orig.)
International Nuclear Information System (INIS)
Guth, A.; Steinhardt, P.
1993-01-01
According to the inflationary model, the universe had a brief period of extraordinary rapid expansion, or inflation, during which its diameter increased by a factor at least 10 25 times larger (and perhaps much larger still) than had been previously thought. All the matter and energy in the universe could have been created from virtually nothing. Features of this article are: comparison of standard and inflationary modes, the horizon problem, the geometry of the universe, spontaneous symmetry breaking and the Higgs mechanism (energy density of the Higgs fields), the flatness problem, the new inflationary universe (new Higgs fields and false vacuum), conserved quantities in the universe. 12 figs., 11 refs
Homogenization and isotropization of an inflationary cosmological model
International Nuclear Information System (INIS)
Barrow, J.D.; Groen, Oe.; Oslo Univ.
1986-01-01
A member of the class of anisotropic and inhomogeneous cosmological models constructed by Wainwright and Goode is investigated. It is shown to describe a universe containing a scalar field which is minimally coupled to gravitation and a positive cosmological constant. It is shown that this cosmological model evolves exponentially rapidly towards the homogeneous and isotropic de Sitter universe model. (orig.)
Study of some chaotic inflationary models in f(R) gravity
Sharif, M.; Nawazish, Iqra
2018-04-01
In this paper, we discuss an inflationary scenario via scalar field and fluid cosmology for an anisotropic homogeneous universe model in f(R) gravity. We consider an equation of state which corresponds to a quasi-de Sitter expansion and investigate the effect of the anisotropy parameter for different values of the deviation parameter. We evaluate potential models like linear, quadratic and quartic models which correspond to chaotic inflation. We construct the observational parameters for a power-law model of f(R) gravity and construct the graphical analysis of tensor-scalar ratio and spectral index which indicates the consistency of these parameters with Planck 2015 data.
From supergravity to antigravity
International Nuclear Information System (INIS)
Scherk, J.
1979-01-01
All known extended supergravity models are shown to lead to a short range cancellation of the gravitational attraction between pairs of particles, a phenomenon known by the name 'Antigravity'. A phenomenological model of antigravity based on supergravity models is proposed where the carrier of the antigravitational force is a spin 1 particle (graviphoton). (Auth.)
Constructing warm inflationary model in brane–antibrane system
Energy Technology Data Exchange (ETDEWEB)
Setare, M.R., E-mail: rezakord@ipm.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Sepehri, A., E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Kamali, V., E-mail: Vkamali@basu.ac.ir [Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, 65178 (Iran, Islamic Republic of)
2014-07-30
Recently, various observational data predicted a possibility that inflation may naturally occur in a warm region. In this scenario, radiation is produced during the inflation epoch and reheating is avoided. The main question arises as to what is the origin of warm inflation in 4D universe? We answer this question in brane–antibrane system. We propose a model that allows all cosmological parameters like the scale factor a, the Hubble parameter H and phantom energy density depend on the equation of state parameter in transverse dimension between two branes. Thus, an enhancement in these parameters can be a signature of some evolutions in extra dimension. In our model, the expansion of 4D universe is controlled by the separation distance between branes and evolves from non-phantom phase to phantom one. Consequently, phantom-dominated era of the universe accelerates and ends up in big-rip singularity. Also, we show that as the tachyon potential increases, the effect of interaction between branes on the 4D universe expansion becomes systematically more effective, because at higher energies there exist more channels for flowing energy from extra dimension to other four dimensions. Finally, we test our model against WMAP and Planck data and obtain the ripping time. According to experimental data, N≃50 case leads to n{sub s}≃0.96, where N and n{sub s} are the number e-folds and the spectral index respectively. This standard case may be found in 0.01
Formation of a ''child'' universe in an inflationary cosmological model
International Nuclear Information System (INIS)
Holcomb, K.A.; Park, S.J.; Vishniac, E.T.
1989-01-01
The evolution of a flat, spherically symmetric cosmological model, containing radiation and an inhomogeneous scalar field, is simulated numerically to determine whether the inhomogeneity could cause a ''child'' universe, connected by a wormhole to the external universe, to form. The gravitational and field quantities were computed self-consistently by means of the techniques of numerical relativity. Although we were unable to follow the process to its completion, preliminary indications are that the ''budding'' phenomenon could occur under very general initial conditions, as long as the scalar field is sufficiently inhomogeneous that the wormhole forms before the inflation is damped by the expansion of the background spacetime
Constraining quantum collapse inflationary models with CMB data
Energy Technology Data Exchange (ETDEWEB)
Benetti, Micol; Alcaniz, Jailson S. [Departamento de Astronomia, Observatório Nacional, 20921-400, Rio de Janeiro, RJ (Brazil); Landau, Susana J., E-mail: micolbenetti@on.br, E-mail: slandau@df.uba.ar, E-mail: alcaniz@on.br [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, PabI, Buenos Aires 1428 (Argentina)
2016-12-01
The hypothesis of the self-induced collapse of the inflaton wave function was proposed as responsible for the emergence of inhomogeneity and anisotropy at all scales. This proposal was studied within an almost de Sitter space-time approximation for the background, which led to a perfect scale-invariant power spectrum, and also for a quasi-de Sitter background, which allows to distinguish departures from the standard approach due to the inclusion of the collapse hypothesis. In this work we perform a Bayesian model comparison for two different choices of the self-induced collapse in a full quasi-de Sitter expansion scenario. In particular, we analyze the possibility of detecting the imprint of these collapse schemes at low multipoles of the anisotropy temperature power spectrum of the Cosmic Microwave Background (CMB) using the most recent data provided by the Planck Collaboration. Our results show that one of the two collapse schemes analyzed provides the same Bayesian evidence of the minimal standard cosmological model ΛCDM, while the other scenario is weakly disfavoured with respect to the standard cosmology.
SUSY signals at DESY HERA in the no-scale flipped SU(5) supergravity model
Energy Technology Data Exchange (ETDEWEB)
Lopez, J.L.; Nanopoulos, D.V.; Wang, X.; Zichichi, A. (Center for Theoretical Physics, Department of Physics, Texas A M University, College Station, Texas 77843-4242 (United States) Astroparticle Physics Group, Houston Advanced Research Center (HARC), The Woodlands, Texas 77381 (United States) CERN, Geneva (Switzerland))
1993-11-01
Sparticle production and detection at DESY HERA are studied within the recently proposed no-scale flipped SU(5) supergravity model. Among the various reaction channels that could lead to sparticle production at HERA, only the following are within its limit of sensitivity in this model: [ital e][sup [minus
Primordial non-Gaussianities in single field inflationary models with non-trivial initial states
Energy Technology Data Exchange (ETDEWEB)
Bahrami, Sina; Flanagan, Éanna É., E-mail: sb933@cornell.edu, E-mail: eef3@cornell.edu [Department of Physics, Cornell University, Ithaca, NY 14853 (United States)
2014-10-01
We compute the non-Gaussianities that arise in single field, slow roll inflationary models arising from arbitrary homogeneous initial states, as well as subleading contributions to the power spectrum. Non Bunch-Davies vacuum initial states can arise if the transition to the single field, slow roll inflation phase occurs only shortly before observable modes left the horizon. They can also arise from new physics at high energies that has been integrated out. Our general result for the bispectrum exhibits several features that were previously seen in special cases.
Quantum creation of the universe in N = 8 supergravity
International Nuclear Information System (INIS)
Goncharov, Yu.P.; Bytsenko, A.A.
1988-01-01
We discuss the possibility of quantum creation of an inflationary universe filled with the fields of maximal extended N = 8 supergravity. If the created universe has spatial topology (S 1 ) 3 and after the creation Starobinskii's inflationary scenario through the topological Casimir effect in N = 8 supergravity is realized, the probability of creation of such a universe can be estimated in the semiclassical approximation. The estimate shows that the creation of a universe with a more isotropic topology is more probable
A short review of supergravity
International Nuclear Information System (INIS)
Scherk, J.
1980-01-01
The perennial question: 'Why fermions' finally answered. A dictionnary of Superwords. The Superalgebras used by Supersymmetrists. The representations of the Super Poincare algebra. What is Super about Supergravity. Extra spatial dimensions and Supergravity. Physical content of the N=8 model. General features of a Supersymmetric World. Antigravity and Supergravity: a crazy idea. Conclusion left to a well-known physicist
Minimal constrained supergravity
Energy Technology Data Exchange (ETDEWEB)
Cribiori, N. [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Dall' Agata, G., E-mail: dallagat@pd.infn.it [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Farakos, F. [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Porrati, M. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States)
2017-01-10
We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.
Minimal constrained supergravity
Directory of Open Access Journals (Sweden)
N. Cribiori
2017-01-01
Full Text Available We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.
Minimal constrained supergravity
International Nuclear Information System (INIS)
Cribiori, N.; Dall'Agata, G.; Farakos, F.; Porrati, M.
2017-01-01
We describe minimal supergravity models where supersymmetry is non-linearly realized via constrained superfields. We show that the resulting actions differ from the so called “de Sitter” supergravities because we consider constraints eliminating directly the auxiliary fields of the gravity multiplet.
Supersymmetry and supergravity
International Nuclear Information System (INIS)
West, P.
1986-01-01
This book presents a pedagogical introduction of supersymmetry, supergravity and string theories and deals with advanced related topics. Contents: Introduction, The Supersymmetry Algebras; Alternative Approach to the Supersymmetry Algebra; Immediate Consequences of the Supersymmetry Algebra; The Wess-Zumino Model; N = 1 Super QED; N = 1 Super Yang-Mills Theory and the Noether Procedure; Irreducible Representations of Supersymmetry; Simple Supergravity; Invariance of Simple Supergravity; Tensor Calculus of Rigid Supersymmetry; Theories of Extended Rigid Supersymmetry; Local Tensor Calculus and the Coupling of Supergravity to Matter; Superspace; Superspace Formulations of Rigid Supersymmetric Theories; Superspace Formulation of N = 1 Supergravity; N = 1 Super-Feynman Rules; Ultraviolet Properties of the Extended Rigid Supersymmetry Theories; Spontaneous Breaking of Supersymmetry and Realistic Models; Currents in Supersymmetric Theories; Two-Dimensional Supersymmetry Models; Gauge Covariant Formulation of Strings; Appendix A: An Explanation of Our Choices of Conventions; Appendix B: A List of Reviews and Books
Physics of superheavy dark matter in supergravity
Addazi, Andrea; Marciano, Antonino; Ketov, Sergei V.; Khlopov, Maxim Yu.
New trends in inflationary model building and dark matter production in supergravity are considered. Starobinsky inflation is embedded into 𝒩 = 1 supergravity, avoiding instability problems, when the inflaton belongs to a vector superfield associated with a U(1) gauge symmetry, instead of a chiral superfield. This gauge symmetry can be spontaneously broken by the super-Higgs mechanism resulting in a massive vector supermultiplet including the (real scalar) inflaton field. Both supersymmetry (SUSY) and the R-symmetry can also be spontaneously broken by the Polonyi mechanism at high scales close to the inflationary scale. In this case, Polonyi particles and gravitinos become superheavy, and can be copiously produced during inflation by the Schwinger mechanism sourced by the universe expansion. The Polonyi mass slightly exceeds twice the gravitino mass, so that Polonyi particles are unstable and decay into gravitinos. Considering the mechanisms of superheavy gravitino production, we find that the right amount of cold dark matter composed of gravitinos can be achieved. In our scenario, the parameter space of the inflaton potential is directly related to the dark matter one, providing a new unifying framework of inflation and dark matter genesis. A multi-superfield extension of the supergravity framework with a single (inflaton) superfield can result in a formation of primordial nonlinear structures like mini- and stellar-mass black holes, primordial nongaussianity, and the running spectral index of density fluctuations. This framework can be embedded into the SUSY GUTs inspired by heterotic string compactifications on Calabi-Yau three-folds, thus unifying particle physics with quantum gravity.
Cosmological perturbations in warm-tachyon inflationary universe model with viscous pressure
International Nuclear Information System (INIS)
Setare, M.R.; Kamali, V.
2014-01-01
We study the warm-tachyon inflationary universe model with viscous pressure in high-dissipation regime. General conditions which are required for this model to be realizable are derived in the slow-roll approximation. We present analytic expressions for density perturbation and amplitude of tensor perturbation in longitudinal gauge. Expressions of tensor-to-scalar ratio, scalar spectral index and its running are obtained. We develop our model by using exponential potential, the characteristics of this model are calculated for two specific cases in great details: 1. Dissipative parameter Γ and bulk viscous parameter ζ are constant parameters. 2. Dissipative parameter is a function of tachyon field ϕ and bulk viscous parameter is a function of matter-radiation mixture energy density ρ. The parameters of the model are restricted by recent observational data from the nine-year Wilkinson microwave anisotropy probe (WMAP9), Planck and BICEP2 data.
Cosmological perturbations in warm-tachyon inflationary universe model with viscous pressure
Energy Technology Data Exchange (ETDEWEB)
Setare, M.R., E-mail: rezakord@ipm.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Kamali, V., E-mail: vkamali1362@gmail.com [Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, 65178 (Iran, Islamic Republic of)
2014-09-07
We study the warm-tachyon inflationary universe model with viscous pressure in high-dissipation regime. General conditions which are required for this model to be realizable are derived in the slow-roll approximation. We present analytic expressions for density perturbation and amplitude of tensor perturbation in longitudinal gauge. Expressions of tensor-to-scalar ratio, scalar spectral index and its running are obtained. We develop our model by using exponential potential, the characteristics of this model are calculated for two specific cases in great details: 1. Dissipative parameter Γ and bulk viscous parameter ζ are constant parameters. 2. Dissipative parameter is a function of tachyon field ϕ and bulk viscous parameter is a function of matter-radiation mixture energy density ρ. The parameters of the model are restricted by recent observational data from the nine-year Wilkinson microwave anisotropy probe (WMAP9), Planck and BICEP2 data.
Cosmological perturbations in warm-tachyon inflationary universe model with viscous pressure
Directory of Open Access Journals (Sweden)
M.R. Setare
2014-09-01
Full Text Available We study the warm-tachyon inflationary universe model with viscous pressure in high-dissipation regime. General conditions which are required for this model to be realizable are derived in the slow-roll approximation. We present analytic expressions for density perturbation and amplitude of tensor perturbation in longitudinal gauge. Expressions of tensor-to-scalar ratio, scalar spectral index and its running are obtained. We develop our model by using exponential potential, the characteristics of this model are calculated for two specific cases in great details: 1. Dissipative parameter Γ and bulk viscous parameter ζ are constant parameters. 2. Dissipative parameter is a function of tachyon field ϕ and bulk viscous parameter is a function of matter-radiation mixture energy density ρ. The parameters of the model are restricted by recent observational data from the nine-year Wilkinson microwave anisotropy probe (WMAP9, Planck and BICEP2 data.
Quantum-Gravitational Effects on Primordial Power Spectra in Slow-Roll Inflationary Models
Directory of Open Access Journals (Sweden)
David Brizuela
2018-01-01
Full Text Available We review the computation of the power spectra of inflationary gauge-invariant perturbations in the context of canonical quantum gravity for generic slow-roll models. A semiclassical approximation, based on an expansion in inverse powers of the Planck mass, is applied to the complete Wheeler–DeWitt equation describing a perturbed inflationary universe. This expansion leads to a hierarchy of equations at consecutive orders of the approximation and allows us to write down a corrected Schrödinger equation that encodes information about quantum-gravitational effects. The analytical dependence of the correction to the power spectrum on the wavenumber is obtained. Nonetheless, some numerical work is needed in order to obtain its precise value. Finally, it is shown that the correction turns out to be positive, which leads to an enhancement of the power spectrum especially prominent for large scales. We will also discuss whether this correction leads to a measurable effect in the cosmic microwave background anisotropies.
A Bayesian analysis of inflationary primordial spectrum models using Planck data
Santos da Costa, Simony; Benetti, Micol; Alcaniz, Jailson
2018-03-01
The current available Cosmic Microwave Background (CMB) data show an anomalously low value of the CMB temperature fluctuations at large angular scales (l power is not explained by the minimal ΛCDM model, and one of the possible mechanisms explored in the literature to address this problem is the presence of features in the primordial power spectrum (PPS) motivated by the early universe physics. In this paper, we analyse a set of cutoff inflationary PPS models using a Bayesian model comparison approach in light of the latest CMB data from the Planck Collaboration. Our results show that the standard power-law parameterisation is preferred over all models considered in the analysis, which motivates the search for alternative explanations for the observed lack of power in the CMB anisotropy spectrum.
2D supergravity and its connection to integrable models
International Nuclear Information System (INIS)
Arnaudov, L.N.; Prodanov, E.M.; Rashkov, R.C.
1993-05-01
In the recent work two different approaches for obtaining the covariant W 2 -action of 2-d quantum supergravity are considered. The first one is based on Hamiltonian reduction of flat Osp(2/1) connection in holomorphic polarization. Adding extra degrees of freedom with the help of gauging procedure the W 2 -action and the superconformal identities are obtained. It is shown that the super Virasoro transformations preserve the form of the Lax connection and therefore are symmetries of the sKdV equations. In the second approach starting with Chern-Simons theory and using non-canonical polarization the zero-curvature condition entails the same results. (author). 7 refs
Inflationary implications of supersymmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Borghese, Andrea; Roest, Diederik; Zavala, Ivonne [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)
2013-07-23
We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll parameters and the geometry of the Kähler manifold of the chiral scalars. We analyse the inflationary implications of this bound, and in particular discuss to what extent the requirements of single field and slow-roll can both be met in F-term inflation.
Comments on Nonlinear Sigma Models Coupled to Supergravity arXiv
Ferrara, Sergio
2017-12-10
N=1 , D=4 nonlinear sigma models, parametrized by chiral superfields, usually describe Kählerian geometries, provided that Einstein frame supergravity is used. The sigma model metric is no longer Kähler when local supersymmetry becomes nonlinearly realized through the nilpotency of the supergravity auxiliary fields. In some cases the nonlinear realization eliminates one scalar propagating degree of freedom. This happens when the sigma model conformal-frame metric has co-rank 2. In the geometry of the inflaton, this effect eliminates its scalar superpartner. We show that the sigma model metric remains semidefinite positive in all cases, due the to positivity properties of the conformal-frame sigma model metric.
Developments in inflationary cosmology
Indian Academy of Sciences (India)
. First a brief review is given of the inflation scenario and its basic models. After that, one of the main problems in developing inflationary models has been the requirement of a very flat inflation potential. In solving this problem, supersymmetry ...
Fermion mass hierarchies in low-energy supergravity and superstring models
International Nuclear Information System (INIS)
Binetruy, P.
1995-01-01
We investigate the problem of the fermion mass hierarchy in supergravity models with flat directions of the scalar potential associated with some gauge singlet moduli fields. The low-energy Yukawa couplings are non-trivial homogeneous functions of the moduli and a geometric constraint between them plays, in a large class of models, a crucial role in generating hierarchies. Explicit examples are given for no-scale type supergravity models. The Yukawa couplings are dynamical variables at low energy, to be determined by a minimization process which amounts to fixing ratios of the moduli fields. The Minimal Supersymmetric Standard Model is studied and the constraints needed on the parameters in order to have a top quark much heavier than the other fermions are worked out. The bottom mass is explicitly computed and shown to be compatible with the experimental data for a large region of the parameter space. ((orig.))
Stochastic dynamics of an inflationary model and initial distribution of universes
International Nuclear Information System (INIS)
Nambu, Yasusada.
1989-01-01
We investigate the stationary solution of the modified Fokker-Planck equation which governs the global dynamics of the inflation. Contrary to the original FP equation which is for a Hubble horizon size region, we found that the normalizable stationary solution can exist for modified Fokker-Planck equation which is for many Hubble horizon size regions. For a chaotic inflationary model with the potential λψ 2n , we get initial distribution of classical universes using this solution, and discussed the physical meaning of it. Especially for n = 2, this distribution obeys power-law and classical universes which created from the Planck energy region make the fractal structure. Other cases n ≠ 2, creation of large classical universes are strongly suppressed. (author)
Brane inflation: A field theory approach in background supergravity
International Nuclear Information System (INIS)
Choudhury, Sayantan; Pal, Supratik
2012-01-01
We propose a model of inflation in the framework of brane cosmology driven by background supergravity. Starting from bulk supergravity we construct the inflaton potential on the brane and employ it to investigate for the consequences to inflationary paradigm. To this end, we derive the expressions for the important parameters in brane inflation, which are somewhat different from their counterparts in standard cosmology, using the one loop radiative corrected potential. We further estimate the observable parameters and find them to fit well with recent observational data. We have studied extensively reheating phenomenology, which explains the thermal history of the universe and leptogenesis through the production of thermal gravitino pertaining to the particle physics phenomenology of the early universe.
International Nuclear Information System (INIS)
Uehara, S.
1985-01-01
Of all supergravity theories, the maximal, i.e., N = 8 in 4-dimension or N = 1 in 11-dimension, theory should perform the unification since it owns the highest degree of symmetry. As to the N = 1 in d = 11 theory, it has been investigated how to compactify to the d = 4 theories. From the phenomenological point of view, local SUSY GUTs, i.e., N = 1 SUSY GUTs with soft breaking terms, have been studied from various angles. The structures of extended supergravity theories are less understood than those of N = 1 supergravity theories, and matter couplings in N = 2 extended supergravity theories are under investigation. The harmonic superspace was recently proposed which may be useful to investigate the quantum effects of extended supersymmetry and supergravity theories. As to the so-called Kaluza-Klein supergravity, there is another possibility. (Mori, K.)
Indian Academy of Sciences (India)
The inflationary paradigm provides a robust description of the peculiar initial conditions which are required for the success of the hot Big Bang model of cosmology, as well as of the recent precision measurements of temperature fluctuations within the cosmic microwave background. Furthermore, the success of this ...
Precision electroweak tests of the minimal and flipped SU(5) supergravity models
Energy Technology Data Exchange (ETDEWEB)
Lopez, J.L.; Nanopoulos, D.V.; Park, G.T.; Pois, H.; Yuan, K. (Center for Theoretical Physics, Department of Physics, Texas A M University, College Station, Texas 77843-4242 (United States) Astroparticle Physics Group, Houston Advanced Research Center (HARC), The Woodlands, Texas 77381 (United States))
1993-10-01
We explore the one-loop electroweak radiative corrections in the minimal SU(5) and the no-scale flipped SU(5) supergravity models via explicit calculation of vacuum polarization contributions to the [epsilon][sub 1,2,3] parameters. Experimentally, [epsilon][sub 1,2,3] are obtained from a global fit to the CERN LEP observables, and [ital M][sub [ital W
Supersymmetric and supergravity theories
International Nuclear Information System (INIS)
Pernici, M.
1986-01-01
The author addressed problems in Kaluza-Klein supergravity, in supersymmetric theories and in string theories. They constructed the following supergravity theories in higher dimensions: the maximal gauged supergravities in five and seven dimensions, both related to the respective ungauged theory, though the latter cannot be obtained by putting the coupling constant of the gauged version to zero (gauge discontinuity); the ten-dimensional N = 2 non-chiral and the six-dimensional N = 4 supergravities, through trivial dimensional reduction of higher dimensional theories. They studied the Kaluza-Klein compactifications of the seven-dimensional supergravity theories and of the ten-dimensional, N = 2 non-chiral supergravity. They obtained the non-compact gaugings and the critical points of the potential of the maximal gauged supergravity in seven dimensions. They computed the non-abelian chiral anomaly in super Yang-Mills theories, using a variation of the Fujikawa method. The covariant action of the SU(2) spinning string is obtained together with its extension to non-linear sigma models. A covariant action for the free open spinning string field theory is constructed by analyzing the BRST transformations
Supersymmetry, supergravity, and unification
Nath, Pran
2017-01-01
This unique book gives a modern account of particle physics and gravity based on supersymmetry and supergravity, two of the most significant developments in theoretical physics since general relativity. The book begins with a brief overview of the history of unification and then goes into a detailed exposition of both fundamental and phenomenological topics. The topics in fundamental physics include Einstein gravity, Yang-Mills theory, anomalies, the standard model, supersymmetry and supergravity, and the construction of supergravity couplings with matter and gauge fields, as well as computational techniques for SO(10) couplings. The topics of phenomenological interest include implications of supergravity models at colliders, CP violation, and proton stability, as well as topics in cosmology such as inflation, leptogenesis, baryogenesis, and dark matter. The book is intended for graduate students and researchers seeking to master the techniques for building grand unified models.
Directory of Open Access Journals (Sweden)
Anna Ijjas
2014-09-01
Full Text Available Classic inflation, the theory described in textbooks, is based on the idea that, beginning from typical initial conditions and assuming a simple inflaton potential with a minimum of fine-tuning, inflation can create exponentially large volumes of space that are generically homogeneous, isotropic and flat, with nearly scale-invariant spectra of density and gravitational wave fluctuations that are adiabatic, Gaussian and have generic predictable properties. In a recent paper, we showed that, in addition to having certain conceptual problems known for decades, classic inflation is for the first time also disfavored by data, specifically the most recent data from WMAP, ACT and Planck2013. Guth, Kaiser and Nomura and Linde have each recently published critiques of our paper, but, as made clear here, we all agree about one thing: the problematic state of classic inflation. Instead, they describe an alternative inflationary paradigm that revises the assumptions and goals of inflation, and perhaps of science generally.
Bianchi type I inflationary universe in general relativity
Indian Academy of Sciences (India)
In this paper, we have investigated Bianchi type I inflationary universe in the presence of massless scalar field with a flat potential. To get an inflationary solution, we have considered a flat region in which potentialV is constant. The inflationary scenario of the model is discussed in detail. Keywords. Inflationary universe ...
Directory of Open Access Journals (Sweden)
Jaggi Chandra K.
2016-01-01
Full Text Available This study develops an inventory model to determine ordering policy for deteriorating items with constant demand rate under inflationary condition over a fixed planning horizon. Shortages are allowed and are partially backlogged. In today’s wobbling economy, especially for long term investment, the effects of inflation cannot be disregarded as uncertainty about future inflation may influence the ordering policy. Therefore, in this paper a fuzzy model is developed that fuzzify the inflation rate, discount rate, deterioration rate, and backlogging parameter by using triangular fuzzy numbers to represent the uncertainty. For Defuzzification, the well known signed distance method is employed to find the total profit over the planning horizon. The objective of the study is to derive the optimal number of cycles and their optimal length so to maximize the net present value of the total profit over a fixed planning horizon. The necessary and sufficient conditions for an optimal solution are characterized. An algorithm is proposed to find the optimal solution. Finally, the proposed model has been validated with numerical example. Sensitivity analysis has been performed to study the impact of various parameters on the optimal solution, and some important managerial implications are presented.
Likelihood analysis of the next-to-minimal supergravity motivated model
International Nuclear Information System (INIS)
Balazs, Csaba; Carter, Daniel
2009-01-01
In anticipation of data from the Large Hadron Collider (LHC) and the potential discovery of supersymmetry, we calculate the odds of the next-to-minimal version of the popular supergravity motivated model (NmSuGra) being discovered at the LHC to be 4:3 (57%). We also demonstrate that viable regions of the NmSuGra parameter space outside the LHC reach can be covered by upgraded versions of dark matter direct detection experiments, such as super-CDMS, at 99% confidence level. Due to the similarities of the models, we expect very similar results for the constrained minimal supersymmetric standard model (CMSSM).
Anomalies of hidden local chiral symmetries in sigma-models and extended supergravities
International Nuclear Information System (INIS)
Vecchia, P. di; Ferrara, S.; Girardello, L.
1985-01-01
Non-linear sigma-models with hidden gauge symmetries are anomalous, at the quantum level, when coupled to chiral fermions in not anomaly free representations of the hidden chiral symmetry. These considerations generally apply to supersymmetric kaehlerian sigma-models on coset spaces with hidden chiral symmetries as well as to extended supergravities in four dimensions with local SU(N) symmetry. The presence of the anomaly implies that the scenario of dynamical generation of gauge vector bosons has to be reconsidered in these theories. (orig.)
Topics in inflationary cosmology
International Nuclear Information System (INIS)
Kahn, R.N.
1985-01-01
This thesis examines several topics in the theory of inflationary cosmology. It first proves the existence of Hawking Radiation during the slow-rolling period of a new inflationary universe. It then derives and somewhat extends Bardeen's gauge invariant formalism for calculating the growth of linear gravitational perturbations in a Friedmann-Robertson-Walker cosmological background. This formalism is then applied, first to several new inflationary universe models all of which show a Zel'dovich spectrum of fluctuations, but with amplitude sigma(100 4 ) above observational limits. The general formalism is next applied to models that exhibit primordial inflation. Fluctuations in these models also exhibit a Zel'dovich spectrum here with an acceptable amplitude. Finally the thesis presents the results of new, numerical calculations. A classical, (2 + 1) dimensional computer model is developed that includes a Higgs field (which drives inflation) along with enough auxiliary fields to generate dynamically not only a thermal bath, but also the fluctuations that naturally accompany that bath. The thesis ends with a discussion of future prospects
de Wit, Bernard; Reys, Valentin
2017-12-01
Supergravity with eight supercharges in a four-dimensional Euclidean space is constructed at the full non-linear level by performing an off-shell time-like reduction of five-dimensional supergravity. The resulting four-dimensional theory is realized off-shell with the Weyl, vector and tensor supermultiplets and a corresponding multiplet calculus. Hypermultiplets are included as well, but they are themselves only realized with on-shell supersymmetry. We also briefly discuss the non-linear supermultiplet. The off-shell reduction leads to a full understanding of the Euclidean theory. A complete multiplet calculus is presented along the lines of the Minkowskian theory. Unlike in Minkowski space, chiral and anti-chiral multiplets are real and supersymmetric actions are generally unbounded from below. Precisely as in the Minkowski case, where one has different formulations of Poincaré supergravity upon introducing different compensating supermultiplets, one can also obtain different versions of Euclidean supergravity.
Introduction to supersymmetry and supergravity
International Nuclear Information System (INIS)
West, P.
1986-01-01
This book gives views of supersymmetry and supergravity. The contents include; alternative approach to supersymmetry algebra; immediate consequences of supersymmetry algebra; Wess-Zumino model. N=1 Super QED. N=1 super Yang Mills theory and the Noether procedure; irreducible representations of supersymmetry; invariance of simple supergravity and theories of extended rigid supersymmetry
Minimal $R+R^2$ Supergravity Models of Inflation Coupled to Matter
Ferrara, S
2014-01-01
The supersymmetric extension of "Starobinsky" $R+\\alpha R^2$ models of inflation is particularly simple in the "new minimal" formalism of supergravity, where the inflaton has no scalar superpartners. This paper is devoted to matter couplings in such supergravity models. We show how in the new minimal formalism matter coupling presents certain features absent in other formalisms. In particular, for the large class of matter couplings considered in this paper, matter must possess an R-symmetry, which is gauged by the vector field which becomes dynamical in the "new minimal" completion of the $R+\\alpha R^2$ theory. Thus, in the dual formulation of the theory, where the gauge vector is part of a massive vector multiplet, the inflaton is the superpartner of the massive vector of a nonlinearly realized R-symmetry. The F-term potential of this theory is of no-scale type, while the inflaton potential is given by the D-term of the gauged R-symmetry. The absolute minimum of the potential is always exactly supersymmetri...
Higher curvature supergravity and cosmology
Energy Technology Data Exchange (ETDEWEB)
Ferrara, Sergio [Th-Ph Department, CERN, Geneva (Switzerland); U.C.L.A., Los Angeles, CA (United States); INFN - LNF, Frascati (Italy); Sagnotti, Augusto [Scuola Normale Superiore, Pisa (Italy); INFN, Pisa (Italy)
2016-04-15
In this contribution we describe dual higher-derivative formulations of some cosmological models based on supergravity. Work in this direction started with the R + R{sup 2} Starobinsky model, whose supersymmetric extension was derived in the late 80's and was recently revived in view of new CMB data. Models dual to higher-derivative theories are subject to more restrictions than their bosonic counterparts or standard supergravity. The three sections are devoted to a brief description of R + R{sup 2} supergravity, to a scale invariant R{sup 2} supergravity and to theories with a nilpotent curvature, whose duals describe non-linear realizations (in the form of a Volkov-Akulov constrained superfield) coupled to supergravity. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Pre-Inflationary Relics in the CMB?
Gruppuso, A.; Mandolesi, N.; Natoli, P.; Sagnotti, A.
String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an imprint in the CMB anisotropy, if it occurred at accessible wavelengths. We model the effect extending $\\Lambda$CDM with a scale $\\Delta$ related to the infrared depression and explore the constraints allowed by {\\sc Planck} data, employing also more conservative, wider Galactic masks in the low resolution CMB likelihood. In an extended mask with $f_{sky}=39\\%$, we thus find $\\Delta = (0.351 \\pm 0.114) \\times 10^{-3} \\, \\mbox{Mpc}^{-1}$, at $99.4\\%$ confidence level, to be compared with a nearby value at $88.5\\%$ with the standard $f_{sky}=94\\%$ mask. With about 64 $e$--folds of inflation, these values for $\\Delta$ would translate into primordial energy scales ${\\cal O}(10^{14})$ GeV.
Supersymmetry and supergravity
International Nuclear Information System (INIS)
Wess, J.; Bagger, J.
1992-01-01
The first edition of this book appeared in 1983 and was based on a series of lectures given at Princeton in 1983 by Julius Wess. Since the appearance of the first edition much work has been done on the development of phenomenological models of particle behavior based on the supergravity multiplet. Some experimental searches have been carried out and others are planned for the future. For this reason the second edition of the book goes substantially beyond the first. Six new chapters have been added for a total of twenty-six and five new appendices for a total of seven. The new chapters and appendices are primarily aimed at deriving the most general supersymmetric gauge invariant theory of chiral fields interacting with supergravity and expressing it in component form. The book is divided into three sections. After a brief introduction, the first part of the book deals with a description of N=1 supersymmetric non-abelian rigid gauge theory of chiral fields. The second part of the book develops a local supersymmetric theory which is supergravity. The final part describes the coupling of supersymmetric chiral fields to supergravity in a gauge invariant way. The book may be recommended as a pedagogical introduction to the theory of N=1 supergravity. Together with the appendices is is completely self-contained, both in notation and in the concepts used, requiring only some knowledge of field theory as a background
International Nuclear Information System (INIS)
Aichelburg, P.C.; Embacher, F.
1987-01-01
In previous work solitons of N = 2 supergravity were described as test particles in an external supergravity field. In the present paper we derive the effective interaction of two solitons by inserting a classical soliton configuration for the background into the Lagrangian and apply a slow-motion and large-distance approximation. We obtain the interaction potential to lowest order that incorporates the effect of the supercharge. The resulting classical system is quantized and, as a final step, an effective quantum field theory is formulated. (Author)
DEFF Research Database (Denmark)
Mahmoudinezhad, Mahvash; Mirzazadeh, Abolfazl; Ghoreishi, Maryam
2017-01-01
of the manufacturer is not perfect and makes inspection errors of Type 1 and Type 2. The second-stage inspection of the manufacturer is at the end of production period without inspection errors. Also, the demand is linear function of time. Once the retailer receives the lot, a 100% screening process of the lot......In this article, an integrated production–distribution model is presented for a manufacturer and retailer supply chain under inflationary conditions, permissible delay in payments, deterioration, imperfect production process and inspection errors. We assume that the first-stage inspection...
Generalized IIB supergravity from exceptional field theory
Energy Technology Data Exchange (ETDEWEB)
Baguet, Arnaud; Magro, Marc; Samtleben, Henning [Laboratoire de Physique, Université Claude Bernard Lyon 1, Ens de Lyon, CNRS,F-69342 Lyon (France)
2017-03-20
The background underlying the η-deformed AdS{sub 5}×S{sup 5} sigma-model is known to satisfy a generalization of the IIB supergravity equations. Their solutions are related by T-duality to solutions of type IIA supergravity with non-isometric linear dilaton. We show how the generalized IIB supergravity equations can be naturally obtained from exceptional field theory. Within this manifestly duality covariant formulation of maximal supergravity, the generalized IIB supergravity equations emerge upon imposing on the fields a simple Scherk-Schwarz ansatz which respects the section constraint.
Inflationary cosmology: First 30+ years
Sato, Katsuhiko; Yokoyama, Jun'ichi
2015-08-01
Starting with an account of historical developments in Japan and Russia, we review inflationary cosmology and its basic predictions in a pedagogical manner. We also introduce the generalized G-inflation model, in terms of which all the known single-field inflation models may be described. This formalism allows us to analyze and compare the many inflationary models that have been proposed simultaneously and within a common framework. Finally, current observational constraints on inflation are reviewed, with particular emphasis on the sensitivity of the inferred constraints to the choice of datasets used.
International Nuclear Information System (INIS)
Aichelburg, P.C.; Embacher, F.
1987-01-01
The Langrangian for a single free soliton in N = 2 supergravity as proposed in an earlier paper, is studied. We analyze the algebra of constraints and discuss the local gauge symmetry due to the existence of first class constraints. The classical motion as well as a Gupta-Bleuler type quantization are given. (Author)
International Nuclear Information System (INIS)
Guth, A.; Steinhardt, P.
1989-01-01
The new inflationary cosmological model discussed here in terms of grand unified theories (GUTs) seems to offer solutions to all the problems associated with the big bang model, such as the existence of magnetic monopoles. Before the first 10 -30 s of the existence of the universe, a brief period of extraordinarily rapid expansion occurred according to the ''inflation'' model. Successes of the big bang model include the three standard testable predictions, but relate to time a second or two after the big bang, namely red-shifts of distant, receding galaxies, measured in the 1920s, the existence of a microwave background radiation, confirmed in 1964, and the abundance of light atomic nuclei such as Helium, Hydrogen and Lithium. Two problems posed by the big bang theory are the horizon problem which seeks an answer to the large-scale uniformity of the universe and the question of energy density which leads to questions about whether the universe is closed, open, or flat. In this new inflationary model the phase transition is driven by random fluctuations of the Higgs fields, thus overcoming the flaw in the original model. (U.K.)
Axions in inflationary cosmology
International Nuclear Information System (INIS)
Linde, A.
1991-01-01
The problem of the cosmological constraints on the axion mass is re-examined. It is argued that in the context of inflationary cosmology the constraint m a > or approx.10 -5 eV can be avoided even when the axion perturbations produced during inflation are taken into account. It is shown also that in most axion models the effective parameter f a rapidly changes during inflation. This modifies some earlier statements concerning isothermal perturbations in the axion cosmology. A hybrid inflation scenario is proposed which combines some advantages of chaotic inflation with specific features of new and/or extended inflation. Its implications for the axion cosmology are discussed. (orig.)
Strongest experimental constraints on SU(5)xU(1) supergravity models
International Nuclear Information System (INIS)
Lopez, J.L.; Nanopoulos, D.V.; Park, G.T.; Zichichi, A.
1994-01-01
We consider a class of well-motivated string-inspired flipped SU(5) supergravity models which include four supersymmetry-breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are needed to describe all new phenomena (m t ,tanβ,m g ). We show that the CERN LEP precise measurements of the electroweak parameters in the form of the ε 1 variable and the CLEO II allowed range for B(b→sγ) are at present the most important experimental constraints on this class of models. For m t approx-gt 155 (165) GeV, the ε 1 constraint [at 90 (95)% C.L.] requires the presence of light charginos (m χ1 ± approx-lt 50--100 GeV depending on m t ). Since all sparticle masses are proportional to m g , m χ1 ± approx-lt 100 GeV implies m χ1 0 approx-lt 55 GeV, m χ2 0 approx-lt 100 GeV, m g approx-lt 360 GeV, m q approx-lt 350 (365) GeV, m e R approx-lt 80 (125) GeV, m e L approx-lt 120 (155) GeV, and m n u approx-lt 100 (140) GeV in the no-scale (dilaton) flipped SU(5) supergravity model. The B(b→sγ) constraint excludes a significant fraction of the otherwise allowed region in the (m χ1 ± ,tanβ) plane (irrespective of the magnitude of the chargino mass), while future experimental improvements will result in decisive tests of these models
Starobinsky-like inflation and running vacuum in the context of Supergravity
Basilakos, Spyros; Solà, Joan
2016-01-01
We describe the primeval inflationary phase of the early Universe within a quantum field theoretical (QFT) framework that can be viewed as the effective action of vacuum decay in the early times. Interestingly enough, the model accounts for the "graceful exit" of the inflationary phase into the standard radiation regime. The underlying QFT framework considered here is Supergravity (SUGRA), more specifically an existing formulation in which the Starobinsky-type inflation (de-Sitter background) emerges from the quantum corrections to the effective action after integrating out the gravitino fields in their (dynamically induced) massive phase. We also demonstrate that the structure of the effective action in this model is consistent with the generic idea of renormalization group (RG) running of the cosmological parameters, specifically it follows from the corresponding RG equation for the vacuum energy density as a function of the Hubble rate, $\\rho_{\\Lambda}(H)$. Overall our combined approach amounts to a concre...
Supergravities and superstrings
International Nuclear Information System (INIS)
Ferrara, S.
1988-01-01
In this paper supergavity theories emerging as the point-field limit of various superstring compactifications are considered, and the higher-order corrections to the standard supergravity Lagrangians are discussed. The structure of the effective Lagrangian for the recently constructed four-dimensional superstring models is also reported
International Nuclear Information System (INIS)
Aichelburg, P.C.; Embacher, F.
1987-01-01
The motion of a soliton in a supergravity background configuration is studied. The dynamics of the soliton is desribed by a trajectory in curved N = 2 superspace. For the proposed Langrangian the moments, the constraints and the generators of local supertranslations are displayed. An additional local gauge symmetry is exhibited. Special emphasis is laid on the classical equations of motion. These turn out to be a supersymmetric generalization of Papapetrou's equation of motion for a spinning particle in a gravitational field. (Author)
Supersymmetry, supergravity and particle physics
International Nuclear Information System (INIS)
Nilles, H.P.
1984-01-01
We give a short introduction to N=1 supersymmetry and supergravity and review the attempts to construct models in which the breakdown scale of the weak interactions is related to supersymmetry breaking. (orig.)
International Nuclear Information System (INIS)
Sasaki, Misao
1983-01-01
We review the recent status of the inflationary cosmology. After exhibiting the essence of difficulties associated with the horizon, flatness and baryon number problems in the standard big-bang cosmology, we discuss that the inflationary universe scenario is one of the most plausible solutions to these fundamental cosmological problems. Since there are two qualitatively different versions of the inflationary universe scenario, we review each of them separately and discuss merits and demerits of each version. The Hawking radiation in de Sitter space is also reviewed since it may play an essential role in the inflationary cosmology. (author)
Energy Technology Data Exchange (ETDEWEB)
Ferrara, Sergio [Physics Department, Theory Unit, CERN,CH 1211, Geneva 23 (Switzerland); INFN - Laboratori Nazionali di Frascati,Via Enrico Fermi 40, I-00044 Frascati (Italy); Department of Physics and Astronomy, University of California,Los Angeles, CA 90095-1547 (United States); Kehagias, Alex [Physics Division, National Technical University of Athens,15780 Zografou, Athens (Greece); Porrati, Massimo [Physics Department, Theory Unit, CERN,CH 1211, Geneva 23 (Switzerland); CCPP, Department of Physics,NYU 4 Washington Pl. New York NY 10003 (United States)
2015-08-03
We formulate R{sup 2} pure supergravity as a scale invariant theory built only in terms of superfields describing the geometry of curved superspace. The standard supergravity duals are obtained in both “old' and “new' minimal formulations of auxiliary fields. These theories have massless fields in de Sitter space as they do in their non supersymmetric counterpart. Remarkably, the dual theory of R{sup 2} supergravity in the new minimal formulation is an extension of the Freedman model, describing a massless gauge field and a massless chiral multiplet in de Sitter space, with inverse radius proportional to the Fayet-Iliopoulos term. This model can be interpreted as the “de-Higgsed' phase of the dual companion theory of R+R{sup 2} supergravity.
Matter couplings in supergravity theories
International Nuclear Information System (INIS)
Bagger, J.A.
1983-01-01
The N = 1 supersymmetric nonlinear sigma model is coupled to supergravity. The results are expressed in the language of Kahler geometry. Topological considerations constrain the scalar fields to lie on a Kahler manifold of restricted type, or a Hodge manifold. For topologically nontrivial manifolds, this leads to the quantization of Newton's constant in terms of the scalar self-coupling. The isometries of the N = 1 model are gauged. This gives a geometrical picture of what might be called the gauge invariant supersymmetric nonlinear sigma model. It also provides a new interpretation of the Fayet-Iliopoulos D-term. The gauge invariant supersymmetric nonlinear sigma model is coupled to N = 1 supergravity. This leads to a deeper understanding of the connections between supergravity, R-invariance and the Fayet-Iliopoulos D-term. It also provides a foundation for phenomenological studies of supergravity theories. Finally, the N = 2 supersymmetric nonlinear sigma model is coupled to supergravity. The scalar fields are found to lie on a negatively curved quaternionic manifold. This implies that matter self-couplings that are allowed in N = 2 supersymmetry are forbidden in N = 2 supergravity, and vice versa
Constraints on modular inflation in supergravity and string theory
International Nuclear Information System (INIS)
Covi, L.; Palma, G.A.; Gomez-Reino, M.; Gross, C.; Louis, J.; Hamburg Univ.; Scrucca, C.A.
2008-05-01
We perform a general algebraic analysis on the possibility of realising slow-roll inflation in the moduli sector of string models. This problem turns out to be very closely related to the characterisation of models admitting metastable vacua with non-negative cosmological constant. In fact, we show that the condition for the existence of viable inflationary trajectories is a deformation of the condition for the existence of metastable de Sitter vacua. This condition depends on the ratio between the scale of inflation and the gravitino mass and becomes stronger as this parameter grows. After performing a general study within arbitrary supergravity models, we analyse the implications of our results in several examples. More concretely, in the case of heterotic and orientifold string compactifications on a Calabi-Yau in the large volume limit we show that there may exist fully viable models, allowing both for inflation and stabilisation. Additionally, we show that subleading corrections breaking the no-scale property shared by these models always allow for slow-roll inflation but with an inflationary scale suppressed with respect to the gravitino scale. A scale of inflation larger than the gravitino scale can also be achieved under more restrictive circumstances and only for certain types of compactifications. (orig.)
Inflation via Gravitino Condensation in Dynamically Broken Supergravity
Alexandre, Jean; Mavromatos, Nick E
2015-01-01
Gravitino-condensate-induced inflation via the super-Higgs effect is a UV-motivated scenario for both inflating the early universe and breaking local supersymmetry dynamically, entirely independent of any coupling to external matter. As an added benefit, this also removes the (as of yet unobserved) massless Goldstino associated to global supersymmetry breaking from the particle spectrum. In this review we detail the pertinent properties and outline previously hidden details of the various steps required in this context in order to make contact with current inflationary phenomenology. The class of models of SUGRA we use to exemplify our approach are minimal four-dimensional N=1 supergravity and conformal extensions thereof (with broken conformal symmetry). Therein, the gravitino condensate itself can play the role of the inflaton, however the requirement of slow-roll necessitates unnaturally large values of the wave-function renormalisation. Nevertheless, there is an alternative scenario that may provide Staro...
Inflation and leptogenesis from right handed sneutrinos in supergravity
International Nuclear Information System (INIS)
Peloso, Marco
2016-01-01
We describe a supergravity model of inflation where the inflaton is identified with one linerar combination of two right handed sneutrino fields. The potential along the inflationary trajectory is flatter than that of massive chaotic inflation, resulting in a detectable but not ruled out tensor-to-scalar ratio r. In general, the potential for the two sneutrinos has complex phases. As a result, the two neutrinos can develop a nonvanishing lepton charge through a simple modification of the Affleck-Dine mechanism. [This talk summarizes the work of Evans, Ghergetta, and Peloso, Phys. Rev. D 92, no. 2, 021303 (2015) (Ref. 1). Please refer to that work for details and for a more comprehensive list of references.
Strongest experimental constraints on SU(5)×U(1) supergravity models
Lopez, Jorge L.; Nanopoulos, D. V.; Park, Gye T.; Zichichi, A.
1994-01-01
We consider a class of well-motivated string-inspired flipped SU(5) supergravity models which include four supersymmetry-breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are needed to describe all new phenomena (mt,tanβ,mg~). We show that the CERN LEP precise measurements of the electroweak parameters in the form of the ɛ1 variable and the CLEO II allowed range for B(b-->sγ) are at present the most important experimental constraints on this class of models. For mt>~155 (165) GeV, the ɛ1 constraint [at 90 (95)% C.L.] requires the presence of light charginos (m+/-χ1360 GeV, mq~sγ) constraint excludes a significant fraction of the otherwise allowed region in the (m+/-χ1,tanβ) plane (irrespective of the magnitude of the chargino mass), while future experimental improvements will result in decisive tests of these models. In light of the ɛ1 constraint, we conclude that the outlook for chargino and selectron detection at LEP II and at DESY HERA is quite favorable in this class of models.
Supersymmetry and supergravity: Phenomenology and grand unification
International Nuclear Information System (INIS)
Arnowitt, R.; Nath, P.
1993-01-01
A survey is given of supersymmetry and supergravity and their phenomenology. Some of the topics discussed are the basic ideas of global supersymmetry, the minimal supersymmetric Standard Model (MSSM) and its phenomenology, the basic ideas of local supersymmetry (supergravity), grand unification, supersymmetry breaking in supergravity grand unified models, radiative breaking of SU(2) x U(1), proton decay, cosmological constraints, and predictions of supergravity grand unified models. While the number of detailed derivations are necessarily limited, a sufficient number of results are given so that a reader can get a working knowledge of this field
Asymptomatic freedom in renormalisable gravity and supergravity
International Nuclear Information System (INIS)
Fradkin, E.S.; Tseytlin, A.A.
1984-01-01
This chapter demonstrates that renormalizable supergravity, which is a superextension of renormalizable quantum gravity, can be the basis for a natural ''induced supergravity'' theory. A perturbatively operational unified theory is needed for a description of the early stages of the Universe, and renormalizable quantum gravity is well suited for unification with the renormalizable Grand Unified Models of matter. Topics considered include one-loop counter-terms and renormalization group (RG) equations for pure renormalizable gravity; the consequences of asymptotic freedom; the inclusion of matter; conformal supergravities; and renormalizable supergravity models. It is concluded that the presented lagrangian, which contains a locally superconformal extension of the Yang-Mills and massless spinor lagrangians and the conformal supergravity term, shows that conformal supergravity may play an important role in a fundamental theory
Simplifications of Einstein supergravity
International Nuclear Information System (INIS)
Ferrara, S.; van Nieuwenhuizen, P.
1979-01-01
Using a new symmetry of the Einstein supergravity action and defining a new spin connection, the axial-vector auxiliary field cancels in the gauge action and in the gauge algebra. This explains why in some models a first-order formalism with minimal coupling of the spin connection and tensor calculus agree, while in other models only the tensor calculus gives the correct result but torsion does not
Large (g-2)$_{\\mu}$ in SU(5) x U(1) supergravity models
López, J L; Wang, X
1994-01-01
We compute the supersymmetric contribution to the anomalous magnetic moment of the muon within the context of $SU(5)\\times U(1)$ supergravity models. The largest possible contributions to $a^{susy}_\\mu$ occur for the largest allowed values of $\\tan\\beta$ and can easily exceed the present experimentally allowed range, even after the LEP lower bounds on the sparticle masses are imposed. Such $\\tan\\beta$ enhancement implies that $a^{susy}_\\mu$ can greatly exceed both the electroweak contribution ($\\approx1.95\\times10^{-9}$) and the present hadronic uncertainty ($\\approx\\pm1.75\\times10^{-9}$). Therefore, the new E821 Brookhaven experiment (with an expected accuracy of $0.4\\times10^{-9}$) should explore a large fraction (if not all) of the parameter space of these models, corresponding to slepton, chargino, and squarks masses as high as 200, 300, and 1000 GeV respectively. Moreover, contrary to popular belief, the $a^{susy}_\\mu$ contribution can have either sign, depending on the sign of the Higgs mixing parameter...
On the gauged Kaehler isometry in minimal supergravity models of inflation
International Nuclear Information System (INIS)
Ferrara, S.; Fre, P.; Sorin, A.S.
2014-01-01
In this paper we address the question how to discriminate whether the gauged isometry group G Σ of the Kaehler manifold Σ that produces a D-type inflaton potential in a Minimal Supergravity Model is elliptic, hyperbolic or parabolic. We show that the classification of isometries of symmetric cosets can be extended to non symmetric Σ.s if these manifolds satisfy additional mathematical restrictions. The classification criteria established in the mathematical literature are coherent with simple criteria formulated in terms of the asymptotic behavior of the Kaehler potential K(C) = 2 J(C) where the real scalar field C encodes the inflaton field. As a by product of our analysis we show that phenomenologically admissible potentials for the description of inflation and in particular α-attractors are mostly obtained from the gauging of a parabolic isometry, this being, in particular the case of the Starobinsky model. Yet at least one exception exists of an elliptic α-attractor, so that neither type of isometry can be a priori excluded. The requirement of regularity of the manifold Σ poses instead strong constraints on the α-attractors and reduces their space considerably. Curiously there is a unique integrable α-attractor corresponding to a particular value of this parameter. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
On the Gauged Kahler Isometry in Minimal Supergravity Models of Inflation
Ferrara, Sergio; Sorin, Alexander S.
2014-01-01
In this paper we address the question how to discriminate whether the gauged isometry group G_Sigma of the Kahler manifold Sigma that produces a D-type inflaton potential in a Minimal Supergravity Model is elliptic, hyperbolic or parabolic. We show that the classification of isometries of symmetric cosets can be extended to non symmetric Sigma.s if these manifolds satisfy additional mathematical restrictions. The classification criteria established in the mathematical literature are coherent with simple criteria formulated in terms of the asymptotic behavior of the Kahler potential K(C) = 2 J(C) where the real scalar field C encodes the inflaton field. As a by product of our analysis we show that all phenomenologically admissible potentials for the description of inflation and in particular alpha-attractors are mostly obtained from the gauging of a parabolic isometry. The requirement of regularity of the manifold Sigma poses strong constraints on the alpha-attractors and reduces their space considerably. Curi...
Expectations for inflationary observables: simple or natural?
Musoke, Nathan; Easther, Richard
2017-12-01
We describe the general inflationary dynamics that can arise with a single, canonically coupled field where the inflaton potential is a 4-th order polynomial. This scenario yields a wide range of combinations of the empirical spectral observables, ns, r and αs. However, not all combinations are possible and next-generation cosmological experiments have the ability to rule out all inflationary scenarios based on this potential. Further, we construct inflationary priors for this potential based on physically motivated choices for its free parameters. These can be used to determine the degree of tuning associated with different combinations of ns, r and αs and will facilitate treatments of the inflationary model selection problem. Finally, we comment on the implications of these results for the naturalness of the overall inflationary paradigm. We argue that ruling out all simple, renormalizable potentials would not necessarily imply that the inflationary paradigm itself was unnatural, but that this eventuality would increase the importance of building inflationary scenarios in the context of broader paradigms of ultra-high energy physics.
Particle production in the new inflationary cosmology
International Nuclear Information System (INIS)
Abbott, L.F.; Farhi, E.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge; Wise, M.B.
1982-01-01
Techniques are developed for computing particle production due to the time dependence of a scalar field expectation value during a phase transition. We review the new version of the inflationary universe and discuss baryon production in this model. (orig.)
Toward the inflationary paradigm: Lectures on inflationary cosmology
International Nuclear Information System (INIS)
Turner, M.S.
1987-02-01
Guth's inflationary Universe scenario has revolutionized our thinking about the very early Universe. The inflationary scenario offers the possibility of explaining a handful of very fundamental cosmological facts - the homogeneity, isotropy, and flatness of the Universe, the origin of density inhomogeneities and the origin of the baryon asymmetry, while at the same time avoiding the monopole problem. It is based upon microphysical events which occurred early (t ≤ 10 -34 sec) in the history of the Universe, but well after the planck epoc (t ≥ 10 -43 sec). While Guth's original model was fundamentally flawed, the variant based on the slow-rollover transition proposed by Linde, and Albrecht and Steinhardt (dubbed 'new inflation') appears viable. Although old inflation and the earliest models of new inflation were based upon first order phase transitions associated with spontaneous-symmetry breaking (SSB), it now appears that the inflationary transition is a much more generic phenomenon, being associated with the evolution of a weakly-coupled scalar field which for some reason or other was initially displaced from the minimum of its potential. Models now exist which are based on a wide variety of microphysics: SSB, SUSY/SUGR, compactification of extra dimensions, R 2 gravity, induced gravity, and some random, weakly-coupled scalar field. While there are several models which successfully implement the inflation, none is particularly compelling and all seem somewhat ad hoc. The common distasteful feature of all the successful models is the necessity of a small dimensionless number in the model - usually in the form of a dimensionless coupling of order 10 -15 . All inflationary scenarios rely upon the assumption that vacuum energy was once dynamically very significant, whereas today there exists every evidence that it is not. 133 refs., 17 figs
Supergravity constraints on monojets
International Nuclear Information System (INIS)
Nandi, S.
1986-01-01
In the standard model, supplemented by N = 1 minimal supergravity, all the supersymmetric particle masses can be expressed in terms of a few unknown parameters. The resulting mass relations, and the laboratory and the cosmological bounds on these superpartner masses are used to put constraints on the supersymmetric origin of the CERN monojets. The latest MAC data at PEP excludes the scalar quarks, of masses up to 45 GeV, as the origin of these monojets. The cosmological bounds, for a stable photino, excludes the mass range necessary for the light gluino-heavy squark production interpretation. These difficulties can be avoided by going beyond the minimal supergravity theory. Irrespective of the monojets, the importance of the stable γ as the source of the cosmological dark matter is emphasized
Inflaton decay in supergravity
Energy Technology Data Exchange (ETDEWEB)
Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe
2007-06-15
We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)
Inflaton decay in supergravity
International Nuclear Information System (INIS)
Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.
2007-06-01
We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3) C gauge interactions. (orig.)
Sensitivity of inflationary predictions to pre-inflationary phases
Energy Technology Data Exchange (ETDEWEB)
Bahrami, Sina; Flanagan, Éanna É., E-mail: sb933@cornell.edu, E-mail: eef3@cornell.edu [Department of Physics, Cornell University, Ithaca, NY 14853 (United States)
2016-01-01
How sensitive are the predictions of inflation to pre-inflationary conditions when the number of efolds of inflation is not too large? In an attempt to address this question, we consider a simple model where the inflationary era is preceded by an era dominated by a radiation fluid, which is coupled to the inflaton only gravitationally and which extends back to the Planck era. We show that there is a natural generalized Bunch-Davies vacuum state for perturbations to the coupled inflaton-gravity-fluid system at early times. With this choice of initial state the model predicts interesting deviations from the standard power spectrum of single field slow-roll inflation at large scales. However, the deviations are too small to be observable in near future CMB observations.
Sensitivity of inflationary predictions to pre-inflationary phases
Energy Technology Data Exchange (ETDEWEB)
Bahrami, Sina; Flanagan, Éanna É. [Department of Physics, Cornell University,Ithaca, NY 14853 (United States)
2016-01-15
How sensitive are the predictions of inflation to pre-inflationary conditions when the number of efolds of inflation is not too large? In an attempt to address this question, we consider a simple model where the inflationary era is preceded by an era dominated by a radiation fluid, which is coupled to the inflaton only gravitationally and which extends back to the Planck era. We show that there is a natural generalized Bunch-Davies vacuum state for perturbations to the coupled inflaton-gravity-fluid system at early times. With this choice of initial state the model predicts interesting deviations from the standard power spectrum of single field slow-roll inflation at large scales. However, the deviations are too small to be observable in near future CMB observations.
Critical constraint on inflationary magnetogenesis
International Nuclear Information System (INIS)
Fujita, Tomohiro; Yokoyama, Shuichiro
2014-01-01
Recently, there are several reports that the cosmic magnetic fields on Mpc scale in void region is larger than ∼ 10 −15 G with an uncertainty of a few orders from the current blazar observations. On the other hand, in inflationary magnetogenesis models, additional primordial curvature perturbations are inevitably produced from iso-curvature perturbations due to generated electromagnetic fields. We explore such induced curvature perturbations in a model independent way and obtained a severe upper bound for the energy scale of inflation from the observed cosmic magnetic fields and the observed amplitude of the curvature perturbation , as ρ inf 1/4 < 300MeV × (B obs /10 −15 G) −1 where B obs is the strength of the magnetic field at present. Therefore, without a dedicated low energy inflation model or an additional amplification of magnetic fields after inflation, inflationary magnetogenesis on Mpc scale is generally incompatible with CMB observations
BPS black holes in a non-homogeneous deformation of the stu model of N=2, D=4 gauged supergravity
Energy Technology Data Exchange (ETDEWEB)
Klemm, Dietmar [Dipartimento di Fisica, Università di Milano, and INFN - Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy); Marrani, Alessio [Centro Studi e Ricerche ‘Enrico Fermi’, Via Panisperna 89A, I-00184 Roma (Italy); Dipartimento di Fisica e Astronomia ‘Galileo Galilei’, Università di Padova, and INFN - Sezione di Padova,Via Marzolo 8, I-35131 Padova (Italy); Petri, Nicolò; Santoli, Camilla [Dipartimento di Fisica, Università di Milano, and INFN - Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy)
2015-09-29
We consider a deformation of the well-known stu model of N=2, D=4 supergravity, characterized by a non-homogeneous special Kähler manifold, and by the smallest electric-magnetic duality Lie algebra consistent with its upliftability to five dimensions. We explicitly solve the BPS attractor equations and construct static supersymmetric black holes with radial symmetry, in the context of U(1) dyonic Fayet-Iliopoulos gauging, focussing on axion-free solutions. Due to non-homogeneity of the scalar manifold, the model evades the analysis recently given in the literature. The relevant physical properties of the resulting black hole solution are discussed.
Jaggi, Chandra K.; Khanna, Aditi; Verma, Priyanka
2011-07-01
In today's business transactions, there are various reasons, namely, bulk purchase discounts, re-ordering costs, seasonality of products, inflation induced demand, etc., which force the buyer to order more than the warehouse capacity. Such situations call for additional storage space to store the excess units purchased. This additional storage space is typically a rented warehouse. Inflation plays a very interesting and significant role here: It increases the cost of goods. To safeguard from the rising prices, during the inflation regime, the organisation prefers to keep a higher inventory, thereby increasing the aggregate demand. This additional inventory needs additional storage space, which is facilitated by a rented warehouse. Ignoring the effects of the time value of money and inflation might yield misleading results. In this study, a two-warehouse inventory model with linear trend in demand under inflationary conditions having different rates of deterioration has been developed. Shortages at the owned warehouse are also allowed subject to partial backlogging. The solution methodology provided in the model helps to decide on the feasibility of renting a warehouse. Finally, findings have been illustrated with the help of numerical examples. Comprehensive sensitivity analysis has also been provided.
International Nuclear Information System (INIS)
Hatanaka, Tomoya; Ketov, Sergei V
2006-01-01
A four-dimensional supergravity toy model in an arbitrary self-dual gravi-photon background is constructed in Euclidean space, by freezing out the gravi-photon field strength in the standard N = (1, 1) extended supergravity with two non-chiral gravitini. Our model has local N = (1/2, 0) supersymmetry. Consistency of the model requires the background gravi-photon field strength to be equal to the self-dual (bilinear) anti-chiral gravitino condensate. (letter to the editor)
Particle physics and inflationary cosmology
Linde, Andrei D
1990-01-01
This is the LaTeX version of my book "Particle Physics and Inflationary Cosmology'' (Harwood, Chur, Switzerland, 1990). I decided to put it to hep-th, to make it easily available. Many things happened during the 15 years since the time when it was written. In particular, we have learned a lot about the high temperature behavior in the electroweak theory and about baryogenesis. A discovery of the acceleration of the universe has changed the way we are thinking about the problem of the vacuum energy: Instead of trying to explain why it is zero, we are trying to understand why it is anomalously small. Recent cosmological observations have shown that the universe is flat, or almost exactly flat, and confirmed many other predictions of inflationary theory. Many new versions of this theory have been developed, including hybrid inflation and inflationary models based on string theory. There was a substantial progress in the theory of reheating of the universe after inflation, and in the theory of eternal inflation. ...
Fermilab Tevatron and CERN LEP II probes of minimal and string-motivated supergravity models
International Nuclear Information System (INIS)
Baer, H.; Gunion, J.F.; Kao, C.; Pois, H.
1995-01-01
We explore the ability of the Fermilab Tevatron to probe minimal supersymmetry with high-energy-scale boundary conditions motivated by supersymmetry breaking in the context of minimal and string-motivated supergravity theory. A number of boundary condition possibilities are considered: dilatonlike string boundary conditions applied at the standard GUT unification scale or alternatively at the string scale; and extreme (''no-scale'') minimal supergravity boundary conditions imposed at the GUT scale or string scale. For numerous specific cases within each scenario the sparticle spectra are computed and then fed into ISAGET 7.07 so that explicit signatures can be examined in detail. We find that, for some of the boundary condition choices, large regions of parameter space can be explored via same-sign dilepton and isolated trilepton signals. For other choices, the mass reach of Tevatron collider experiments is much more limited. We also compare the mass reach of Tevatron experiments with the corresponding reach at CERN LEP 200
Fermion loops in the effective potential of N = 1 supergravity, with application to no-scale models
International Nuclear Information System (INIS)
Burton, J.W.
1990-01-01
Powerful and quite general arguments suggest that N = 1 supergravity, and in particular the superstring-inspired no-scale models, may describe the physics of the four-dimensional vacuum at energy densities below the Planck scale. These models are not renormalizable, since they arise as effective theories after the large masses have been integrated out of the fundamental theory; thus, they have divergences in their loop amplitudes that must be regulated by imposing a cutoff. Before physics at experimental energies can be extracted from these models, the true vacuum state or states must be identified: at tree level, the ground states of the effective theories are highly degenerate. Radiative corrections at the one-loop level have been shown to break the degeneracy sufficiently to identify the states of vanishing vacuum energy. As the concluding step in a program to calculate these corrections within a self-consistent cutoff prescription, all fermionic one-loop divergent corrections to the scalar effective potential are evaluated. (The corresponding bosonic contributions have been found elsewhere.) The total effective scalar Lagrange density for N = 1 supergravity is written down, and comments are made about cancellations between the fermionic and bosonic loops. Finally, the result is specialized to a toy no-scale model with a single generation of matter fields, and prospects for eventual phenomenological constraints on theories of this type are briefly discussed. 48 refs
Einstein Inflationary Probe (EIP)
Hinshaw, Gary
2004-01-01
I will discuss plans to develop a concept for the Einstein Inflation Probe: a mission to detect gravity waves from inflation via the unique signature they impart to the cosmic microwave background (CMB) polarization. A sensitive CMB polarization satellite may be the only way to probe physics at the grand-unified theory (GUT) scale, exceeding by 12 orders of magnitude the energies studied at the Large Hadron Collider. A detection of gravity waves would represent a remarkable confirmation of the inflationary paradigm and set the energy scale at which inflation occurred when the universe was a fraction of a second old. Even a strong upper limit to the gravity wave amplitude would be significant, ruling out many common models of inflation, and pointing to inflation occurring at much lower energy, if at all. Measuring gravity waves via the CMB polarization will be challenging. We will undertake a comprehensive study to identify the critical scientific requirements for the mission and their derived instrumental performance requirements. At the core of the study will be an assessment of what is scientifically and experimentally optimal within the scope and purpose of the Einstein Inflation Probe.
Energy Technology Data Exchange (ETDEWEB)
Das, Kumar, E-mail: kumar.das@saha.ac.in; Dutta, Koushik, E-mail: koushik.dutta@saha.ac.in
2014-11-10
We have constructed a large field N-flation model in the supergravity framework. In this simple set-up, N fields collectively drive inflation where each field traverses sub-Planckian field values. This has been realised with a generalisation of the single-field chaotic inflation in supergravity. Interestingly, despite the presence of the field interactions, the dynamics can be described in terms of an effective single field. The observable predictions of our model, i.e., tensor-to-scalar ratio r and scalar spectral index n{sub s}, are akin to the chaotic inflation.
International Nuclear Information System (INIS)
Linde, A.D.
1984-01-01
According to the inflationary universe scenario the universe in the very early stages of its evolution was exponentially expanding in the unstable vacuum-like state. At the end of the exponential expansion the energy of the unstable vacuum transforms into the energy of hot dense matter. Recently it was realised that the exponential expansion of the universe naturally occurs in a wide class of realistic theories of elementary particles. The inflationary universe scenario makes it possible to obtain a simple solution to many longstanding cosmological problems and leads to a crucial modification of the standard point of view of the large-scale structure of the universe. (author)
International Nuclear Information System (INIS)
Binetruy, P.
1985-08-01
The reasons that led to study supersymmetric models in the context of inflation are reviewed by setting up the constraints that candidates to an inflationary scenario must satisfy. The question is raised whether the groundstate of the new scalar field introduced, the inflaton, breaks supersymmetry. This is discussed in connection with the so-called thermal constraint. Some problems about the study of thermal fluctuations are discussed. The different models available are reviewed and the way they address those issues. A discussion of baryon number generation and of the gravitino problem follows. 67 refs., 4 figs
Directory of Open Access Journals (Sweden)
Chandra K. Jaggi
2015-01-01
Full Text Available In today’s competition inherited business world, managing inventory of goods is a major challenge in all the sectors of economy. The demand of an item plays a significant role while managing the stock of goods, as it may depend on several factors viz., inflation, selling price, advertisement, etc. Among these, selling price of an item is a decisive factor for the organization; because in this competitive world of business one is constantly on the lookout for the ways to beat the competition. It is a well-known accepted fact that keeping a reasonable price helps in attracting more customers, which in turn increases the aggregate demand. Thus in order to improve efficiency of business performance organization needs to stock a higher inventory, which needs an additional storage space. Moreover, in today’s unstable global economy there is consequent decline in the real value of money, because the general level of prices of goods and services is rising (i.e., inflation. And since inventories represent a considerable investment for every organization, it is inevitable to consider the effects of inflation and time value of money while determining the optimal inventory policy. With this motivation, this paper is aimed at developing a two-warehouse inventory model for deteriorating items where the demand rate is a decreasing function of the selling price under inflationary conditions. In addition, shortages are allowed and partially backlogged, and the backlogging rate has been considered as an exponentially decreasing function of the waiting time. The model jointly optimizes the initial inventory and the price for the product, so as to maximize the total average profit. Finally, the model is analysed and validated with the help of numerical examples, and a comprehensive sensitivity analysis has been performed which provides some important managerial implications.
International Nuclear Information System (INIS)
Wit, B. de.
1984-06-01
These lectures aim at introducing supergravity in its most simple and direct form. After explaining the main features of graviton and gravitino fields the invariance of simple supergravity in d=4 dimension are proved. The complications for higher-dimensional supergravity are explained and d=11 supergravity is presented. The author discusses supersymmetry in anti-de Sitter space, which allows him to introduce the concept of isometries and Killing spinors and vectors. The breaking of supersymmetry (super-Brout-Englert-Higgs effect), off-shell aspects of supergravity and the superconformal multiplet calculus are dealt with. This is first done for gravity, but also for the structure of simple d=4 conformal supergravity. Finally, the coupling of scalar fields to N=1 and N=2 supergravity as an application of this formalism is discussed. (Auth.)
Non-Gaussianity and statistical anisotropy from vector field populated inflationary models
Dimastrogiovanni, Emanuela; Matarrese, Sabino; Riotto, Antonio
2010-01-01
We present a review of vector field models of inflation and, in particular, of the statistical anisotropy and non-Gaussianity predictions of models with SU(2) vector multiplets. Non-Abelian gauge groups introduce a richer amount of predictions compared to the Abelian ones, mostly because of the presence of vector fields self-interactions. Primordial vector fields can violate isotropy leaving their imprint in the comoving curvature fluctuations zeta at late times. We provide the analytic expressions of the correlation functions of zeta up to fourth order and an analysis of their amplitudes and shapes. The statistical anisotropy signatures expected in these models are important and, potentially, the anisotropic contributions to the bispectrum and the trispectrum can overcome the isotropic parts.
Geometrical interpretation of extended supergravity
International Nuclear Information System (INIS)
Townsend, P.K.; Nieuwenhuizen, P.van
1977-01-01
SO 2 extended supergravity is shown to be a geometrical theory, whose underlying gauge group is OSp(4,2). The couplings which gauge the SO 2 symmetry as well as the accompanying cosmological and masslike terms are directly obtained, and the usual SO 2 model is obtained after a Wigner-Inoenue group contraction. (Auth.)
On reserve money for an EOQ model in an inflationary environment under supplier credits
Singh, S.R.; Jain, R.
2009-01-01
We propose to derive a deterministic inventory model for a stock with time-varying deterioration rate with a linear trend in demand over a finite planning horizon in this study. We assume that the supplier offers a credit limit to the retailer during which there is no interest charged. However, the
The scalar-scalar-tensor inflationary three-point function in the axion monodromy model
Chowdhury, Debika; Sreenath, V.; Sriramkumar, L.
2016-11-01
The axion monodromy model involves a canonical scalar field that is governed by a linear potential with superimposed modulations. The modulations in the potential are responsible for a resonant behavior which gives rise to persisting oscillations in the scalar and, to a smaller extent, in the tensor power spectra. Interestingly, such spectra have been shown to lead to an improved fit to the cosmological data than the more conventional, nearly scale invariant, primordial power spectra. The scalar bi-spectrum in the model too exhibits continued modulations and the resonance is known to boost the amplitude of the scalar non-Gaussianity parameter to rather large values. An analytical expression for the scalar bi-spectrum had been arrived at earlier which, in fact, has been used to compare the model with the cosmic microwave background anisotropies at the level of three-point functions involving scalars. In this work, with future applications in mind, we arrive at a similar analytical template for the scalar-scalar-tensor cross-correlation. We also analytically establish the consistency relation (in the squeezed limit) for this three-point function. We conclude with a summary of the main results obtained.
The scalar-scalar-tensor inflationary three-point function in the axion monodromy model
International Nuclear Information System (INIS)
Chowdhury, Debika; Sriramkumar, L.; Sreenath, V.
2016-01-01
The axion monodromy model involves a canonical scalar field that is governed by a linear potential with superimposed modulations. The modulations in the potential are responsible for a resonant behavior which gives rise to persisting oscillations in the scalar and, to a smaller extent, in the tensor power spectra. Interestingly, such spectra have been shown to lead to an improved fit to the cosmological data than the more conventional, nearly scale invariant, primordial power spectra. The scalar bi-spectrum in the model too exhibits continued modulations and the resonance is known to boost the amplitude of the scalar non-Gaussianity parameter to rather large values. An analytical expression for the scalar bi-spectrum had been arrived at earlier which, in fact, has been used to compare the model with the cosmic microwave background anisotropies at the level of three-point functions involving scalars. In this work, with future applications in mind, we arrive at a similar analytical template for the scalar-scalar-tensor cross-correlation. We also analytically establish the consistency relation (in the squeezed limit) for this three-point function. We conclude with a summary of the main results obtained.
Inflationary universe in deformed phase space scenario
Rasouli, S. M. M.; Saba, Nasim; Farhoudi, Mehrdad; Marto, João; Moniz, P. V.
2018-06-01
We consider a noncommutative (NC) inflationary model with a homogeneous scalar field minimally coupled to gravity. The particular NC inflationary setting herein proposed, produces entirely new consequences as summarized in what follows. We first analyze the free field case and subsequently examine the situation where the scalar field is subjected to a polynomial and exponential potentials. We propose to use a canonical deformation between momenta, in a spatially flat Friedmann-Lemaî tre-Robertson-Walker (FLRW) universe, and while the Friedmann equation (Hamiltonian constraint) remains unaffected the Friedmann acceleration equation (and thus the Klein-Gordon equation) is modified by an extra term linear in the NC parameter. This concrete noncommutativity on the momenta allows interesting dynamics that other NC models seem not to allow. Let us be more precise. This extra term behaves as the sole explicit pressure that under the right circumstances implies a period of accelerated expansion of the universe. We find that in the absence of the scalar field potential, and in contrast with the commutative case, in which the scale factor always decelerates, we obtain an inflationary phase for small negative values of the NC parameter. Subsequently, the period of accelerated expansion is smoothly replaced by an appropriate deceleration phase providing an interesting model regarding the graceful exit problem in inflationary models. This last property is present either in the free field case or under the influence of the scalar field potentials considered here. Moreover, in the case of the free scalar field, we show that not only the horizon problem is solved but also there is some resemblance between the evolution equation of the scale factor associated to our model and that for the R2 (Starobinsky) inflationary model. Therefore, our herein NC model not only can be taken as an appropriate scenario to get a successful kinetic inflation, but also is a convenient setting to
The three-point correlation function of the cosmic microwave background in inflationary models
Gangui, Alejandro; Matarrese, Sabino; Mollerach, Silvia
1994-01-01
We analyze the temperature three-point correlation function and the skewness of the Cosmic Microwave Background (CMB), providing general relations in terms of multipole coefficients. We then focus on applications to large angular scale anisotropies, such as those measured by the {\\em COBE} DMR, calculating the contribution to these quantities from primordial, inflation generated, scalar perturbations, via the Sachs--Wolfe effect. Using the techniques of stochastic inflation we are able to provide a {\\it universal} expression for the ensemble averaged three-point function and for the corresponding skewness, which accounts for all primordial second-order effects. These general expressions would moreover apply to any situation where the bispectrum of the primordial gravitational potential has a {\\em hierarchical} form. Our results are then specialized to a number of relevant models: power-law inflation driven by an exponential potential, chaotic inflation with a quartic and quadratic potential and a particular c...
Supersymmetric inflationary cosmology
International Nuclear Information System (INIS)
Ruiz-Altaba, M.
1986-06-01
An action is presented, within the framework of supergravity unification, which satisfies all experimental and cosmological constraints. In intermediate scale, around 10 10 - 10 11 GeV, arises from a critical examination of inflation, supersymmetry breaking, fermion masses, proton decay, baryogenesis, and electroweak breaking - including neutrino oscillations and CP violation. Careful consideration is given to some relevant calculations. 86 refs., 10 figs., 5 tabs
The evolution of Ω in inflationary universes
International Nuclear Information System (INIS)
Madsen, M.S.; Ellis, G.F.R.
1988-01-01
Phase-plane diagrams are presented showing the evolution of the cosmological density parameter Ω in terms of the Robertson-Walker scale factor S. These diagrams are given for both simple fluids and for mixtures of fluids; this enables construction of such diagrams for inflationary universes, whether the inflation is exponential or power-law inflation. The diagrams enable simple consideration of the evolution of the density parameter in inflationary universe models, and clearly demonstrate that there exist such models leading to any value whatever for Ω at the present day. (author)
Holographic cutoff on inflationary universes
International Nuclear Information System (INIS)
Santos, Fabio M. de N.; Cunha, Bruno Carneiro da
2011-01-01
Full text: Cosmological Inflation has been widely accepted as the standard explanation of the onset of Big-Bang Cosmology. However, many critiques have been made about the lack of an account of quantum gravity degrees of freedom in cosmology. There is no definite consensus in the literature if we should consider the influence of pre-Plackian modes, for example, in inflationary models. We propose here a general approach to take quantum gravity into account by imposing a holographic cutoff on the number of states of cosmological theories. We apply the method to inflationary scalar field models coupled to a generic potential V (φ). This thermodynamic cutoff allow us to assess the relative volume of phase space which inflates for the particular model where V (φ) = m 2 φ 2 /2. The density of states of the model is defined by taking the coincidence limit of the Hadamard Green function G (1) and we use the point-splitting method to regulate the expression. Our conclusion is that inflation has probability very close to one. (author)
Inflationary imprints on dark matter
Energy Technology Data Exchange (ETDEWEB)
Nurmi, Sami; Tenkanen, Tommi; Tuominen, Kimmo, E-mail: sami.nurmi@helsinki.fi, E-mail: tommi.tenkanen@helsinki.fi, E-mail: kimmo.i.tuominen@helsinki.fi [University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FI-00014, University of Helsinki (Finland)
2015-11-01
We show that dark matter abundance and the inflationary scale H could be intimately related. Standard Model extensions with Higgs mediated couplings to new physics typically contain extra scalars displaced from vacuum during inflation. If their coupling to Standard Model is weak, they will not thermalize and may easily constitute too much dark matter reminiscent to the moduli problem. As an example we consider Standard Model extended by a Z{sub 2} symmetric singlet s coupled to the Standard Model Higgs Φ via λ Φ{sup †}Φ s{sup 2}. Dark matter relic density is generated non-thermally for λ ∼< 10{sup −7}. We show that the dark matter yield crucially depends on the inflationary scale. For H∼ 10{sup 10} GeV we find that the singlet self-coupling and mass should lie in the regime λ{sub s}∼> 10{sup −9} and m{sub s}∼< 50 GeV to avoid dark matter overproduction.
Inflationary universe without GUTs
International Nuclear Information System (INIS)
Gunzig, E.; Nardone, P.
1988-01-01
The existence of a primordial inflationary era is unavoidable due to the puzzling nature of semiclassical gravitation, regulated by Einstein's equations and the laws of quantum mechanics. This interaction appears to be controlled by a mass-dependent effective gravitational coupling constant. The latter undergoes an unexpected transition from a classical gravitational attractive to an antigravitational repulsive regime when the corresponding mass of a quantum matter field passes through a definite threshold. This induces in turn a gravitational, spontaneously broken symmetry phenomenon responsible for the presence of an unusual non-Minkowskian ground state: the inflationary de Sitter space-time. This then acquires the status of the primordial cosmological vacuum, the generic configuration of our cosmological history
The power spectrum of inflationary attractors
International Nuclear Information System (INIS)
Broy, Benedict J.; Westphal, Alexander; Roest, Diederik
2014-08-01
Inflationary attractors predict the spectral index and tensor-to-scalar ratio to take specific values that are consistent with Planck. An example is the universal attractor for models with a generalised non-minimal coupling, leading to Starobinsky inflation. In this letter we demonstrate that it also predicts a specific relation between the amplitude of the power spectrum and the number of e-folds. The length and height of the inflationary plateau are related via the non-minimal coupling: in a wide variety of examples, the observed power normalisation leads to at least 55 flat e-foldings. Prior to this phase, the inflationary predictions vary and can account for the observational indications of power loss at large angular scales.
Classical solutions in supergravity
International Nuclear Information System (INIS)
Baaklini, N.S.; Ferrara, S.; Nieuwenhuizen Van, P.
1977-06-01
Classical solutions of supergravity are obtained by making finite global supersymmetry rotation on known solutions of the field equations of the bosonic sector. The Schwarzschild and the Reissner-Nordstoem solutions of general relativity are extended to various supergravity systems and the modification to the perihelion precession of planets is discussed
Applied supersymmetry and supergravity
International Nuclear Information System (INIS)
Nanopoulos, D.V.
1986-01-01
The structure and physical consequences of global and local supersymmetric (SUSY) gauge theories are reviewed. Motivation for SUSY theories, supersymmetry and its physical properties, the observable consequences of SUSY at low energies and super-high energies, physical structure of simple (N=1) supergravity, physics with simple (N=1) supergravity, and the experimental evidence for supersymmetry, are all discussed. (UK)
International Nuclear Information System (INIS)
Salam, A.; Sezgin, E.
1984-10-01
SU(2) gauged N=2 supergravity in d=8 is constructed by generalized dimensional reduction of d=11 supergravity on SU(2) group manifold. The relation between the field equations of the d=8 and those of d=11 supergravities is established. As a byproduct of this, it is shown that certain compactifications of d=11 supergravity give rise to anti-de Sitter space-time (AdS)xS 4 or AdSxCP 2 (with or without SU(2) instanton) or AdSxS 2 xS 2 compactifications of d=8 supergravity. The latter two solutions have no supersymmetry, while AdSxS 4 has N=0 or N=1 supersymmetry. (author)
Tanii, Yoshiaki
2014-01-01
This book is a pedagogical introduction to supergravity, a gravitational field theory that includes supersymmetry (symmetry between bosons and fermions) and is a generalization of Einstein's general relativity. Supergravity provides a low-energy effective theory of superstring theory, which has attracted much attention as a candidate for the unified theory of fundamental particles, and it is a useful tool for studying non-perturbative properties of superstring theory such as D-branes and string duality. This work considers classical supergravities in four and higher spacetime dimensions with their applications to superstring theory in mind. More concretely, it discusses classical Lagrangians (or field equations) and symmetry properties of supergravities. Besides local symmetries, supergravities often have global non-compact symmetries, which play a crucial role in their applications to superstring theory. One of the main features of this book is its detailed discussion of these non-compact symmetries. The aim...
Inflationary paradigm in trouble after Planck2013
Energy Technology Data Exchange (ETDEWEB)
Ijjas, Anna, E-mail: aijjas@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); University Observatory Munich, 81679 Munich (Germany); Steinhardt, Paul J., E-mail: steinh@princeton.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Department of Physics, Princeton University, Princeton, NJ 08544 (United States); Princeton Center for Theoretical Science, Princeton University, Princeton, NJ 08544 (United States); Loeb, Abraham, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
2013-06-25
Recent results from the Planck satellite combined with earlier observations from WMAP, ACT, SPT and other experiments eliminate a wide spectrum of more complex inflationary models and favor models with a single scalar field, as reported by the Planck Collaboration. More important, though, is that all the simplest inflaton models are disfavored statistically relative to those with plateau-like potentials. We discuss how a restriction to plateau-like models has three independent serious drawbacks: it exacerbates both the initial conditions problem and the multiverse-unpredictability problem and it creates a new difficulty that we call the inflationary “unlikeliness problem.” Finally, we comment on problems reconciling inflation with a standard model Higgs, as suggested by recent LHC results. In sum, we find that recent experimental data disfavors all the best-motivated inflationary scenarios and introduces new, serious difficulties that cut to the core of the inflationary paradigm. Forthcoming searches for B-modes, non-Gaussianity and new particles should be decisive.
Conformal invariance in supergravity
International Nuclear Information System (INIS)
Bergshoeff, E.A.
1983-01-01
In this thesis the author explains the role of conformal invariance in supergravity. He presents the complete structure of extended conformal supergravity for N <= 4. The outline of this work is as follows. In chapter 2 he briefly summarizes the essential properties of supersymmetry and supergravity and indicates the use of conformal invariance in supergravity. The idea that the introduction of additional symmetry transformations can make clear the structure of a field theory is not reserved to supergravity only. By means of some simple examples it is shown in chapter 3 how one can always introduce additional gauge transformations in a theory of massive vector fields. Moreover it is shown how the gauge invariant formulation sometimes explains the quantum mechanical properties of the theory. In chapter 4 the author defines the conformal transformations and summarizes their main properties. He explains how these conformal transformations can be used to analyse the structure of gravity. The supersymmetric extension of these results is discussed in chapter 5. Here he describes as an example how N=1 supergravity can be reformulated in a conformally-invariant way. He also shows that beyond N=1 the gauge fields of the superconformal symmetries do not constitute an off-shell field representation of extended conformal supergravity. Therefore, in chapter 6, a systematic method to construct the off-shell formulation of all extended conformal supergravity theories with N <= 4 is developed. As an example he uses this method to construct N=1 conformal supergravity. Finally, in chapter 7 N=4 conformal supergravity is discussed. (Auth.)
Bulk-viscosity-driven asymmetric inflationary universe
International Nuclear Information System (INIS)
Waga, I.; Lima, J.A.S.; Portugal, R.
1987-01-01
A primordial net bosinic charge is introduced in the context of the bulk-viscosity-driven inflationary models. The analysis is carried through a macroscopic point of view in the framework of the causal thermodynamic theory. The conditions for having exponetial and generalized inflation are obtained. A phenomenological expression for the bulk viscosity coefficient is also derived. (author) [pt
Tsamis, N. C.; Woodard, R. P.
2004-05-01
We argue that Lambda-driven inflation must overshoot into an era of deflation. The deflationary period ends quickly with the creation of a hot dense thermal barrier to the forward propagation of quantum correlations from the period of inflationary particle production. Subsequent evolution is controlled by the balance between the persistence of this barrier and the growth in the 4-volume from which such correlations can be seen. This balance can lead to power law expansion. Based on an invited talk given at the 8th International Atomic Energy Agency Technical Meeting on Energetic Particles in Magnetic Confinement Systems San Diego, USA, 6 8 October 2003.
Difficulties with inflationary cosmology
International Nuclear Information System (INIS)
Penrose, R.
1989-01-01
According to the author, the idea of inflationary cosmology is an ingenious attempt to solve some of the major puzzles of cosmology, most notably the flatness problem, the homogeneity (horizon) problem, and the monopole problem. The homogeneity problem, in particular, is intimately connected with a largely unappreciated, but profound puzzle presented by the second law of thermodynamics. The author argues that the mechanism of inflation does not, by itself, come to terms with this and consequently, comes nowhere close to providing an understanding of the large-scale homogeneity of the universe
Minimalism in Inflation Model Building
Dvali, Gia; Dvali, Gia; Riotto, Antonio
1998-01-01
In this paper we demand that a successfull inflationary scenario should follow from a model entirely motivated by particle physics considerations. We show that such a connection is indeed possible within the framework of concrete supersymmetric Grand Unified Theories where the doublet-triplet splitting problem is naturally solved. The Fayet-Iliopoulos D-term of a gauge $U(1)_{\\xi}$ symmetry, which plays a crucial role in the solution of the doublet-triplet splitting problem, simultaneously provides a built-in inflationary slope protected from dangerous supergravity corrections.
Minimalism in inflation model building
Dvali, Gia; Riotto, Antonio
1998-01-01
In this paper we demand that a successful inflationary scenario should follow from a model entirely motivated by particle physics considerations. We show that such a connection is indeed possible within the framework of concrete supersymmetric Grand Unified Theories where the doublet-triplet splitting problem is naturally solved. The Fayet-Iliopoulos D-term of a gauge U(1)ξ symmetry, which plays a crucial role in the solution of the doublet-triplet splitting problem, simultaneously provides a built-in inflationary slope protected from dangerous supergravity corrections.
Starobinsky-Like Inflation and Running Vacuum in the Context of Supergravity
Directory of Open Access Journals (Sweden)
Spyros Basilakos
2016-07-01
Full Text Available We describe the primeval inflationary phase of the early Universe within a quantum field theoretical (QFT framework that can be viewed as the effective action of vacuum decay in the early times. Interestingly enough, the model accounts for the “graceful exit” of the inflationary phase into the standard radiation regime. The underlying QFT framework considered here is supergravity (SUGRA, more specifically an existing formulation in which the Starobinsky-type inflation (de Sitter background emerges from the quantum corrections to the effective action after integrating out the gravitino fields in their (dynamically induced massive phase. We also demonstrate that the structure of the effective action in this model is consistent with the generic idea of re-normalization group (RG running of the cosmological parameters; specifically, it follows from the corresponding RG equation for the vacuum energy density as a function of the Hubble rate, ρ Λ ( H . Overall, our combined approach amounts to a concrete-model realization of inflation triggered by vacuum decay in a fundamental physics context, which, as it turns out, can also be extended for the remaining epochs of the cosmological evolution until the current dark energy era.
Generalized pole inflation: Hilltop, natural, and chaotic inflationary attractors
Energy Technology Data Exchange (ETDEWEB)
Terada, Takahiro, E-mail: takahiro.terada@apctp.org [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Asia Pacific Center for Theoretical Physics, Pohang 37673 (Korea, Republic of)
2016-09-10
A reformulation of inflationary model analyses appeared recently, in which inflationary observables are determined by the structure of a pole in the inflaton kinetic term rather than the shape of the inflaton potential. We comprehensively study this framework with an arbitrary order of the pole taking into account possible additional poles in the kinetic term or in the potential. Depending on the setup, the canonical potential becomes the form of hilltop or plateau models, variants of natural inflation, power-law inflation, or monomial/polynomial chaotic inflation. We demonstrate attractor behaviors of these models and compute corrections from the additional poles to the inflationary observables.
Composite gravity and composite supergravity
International Nuclear Information System (INIS)
Lukierski, J.
1982-09-01
It is known that the composite YM H-gauge theory can be constructed from σ-fields taking values in a symmetric Riemannian space G/H. We extend such a framework to graded σ-fields taking values in supercosets. We show that from supercoset σ-fields one can construct composite gravity, and from supercoset σ-superfields the composite supergravity models. (author)
Potentials in N=2 supergravity
International Nuclear Information System (INIS)
Zinov'ev, Yu.M.
1985-01-01
The potentials and Yukava interactions, that arise while introducing a gauge interaction of vector and scalar multiplets in N=2 supergravity are presented, in this the gauge group may be either compact or noncompact. The scalar multiplets geometry corresponds to nonlinear σ, models of the form Sp(2,2n)/Sp(2)xSp(2n), SU(2,n)/SU(2)SU(n)xU(1) and O(4,n)/O(4)xO(n)
Fluctuations in the inflationary universe
Hawking, S. W.; Moss, I. G.
1983-08-01
In the usual treatment of the inflationary universe, it is assumed that the expectation value of some component of the Higgs field develops a non-zero symmetry breaking value Φ0. However, in the models normally considered, the expectation value of Φ will be zero at all times because Φ and -Φ are equally probable. To overcome this difficulty, we calculate the effective action as a function of rather than . This also solves the infra-red problem associated with a Coleman-Weinberg condition in de Sitter space. The expectation value of Φ2 grows linearly with time at first and then as (t2 - t-1). The irregularities in the resulting universe are smaller than those predicted by previous authors, though in the case of the standard SU(5) GUT they are still bigger than the limit set by the microwave background.
Higher derivative couplings and massive supergravity in three dimensions
Energy Technology Data Exchange (ETDEWEB)
Kuzenko, Sergei M.; Novak, Joseph [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Tartaglino-Mazzucchelli, Gabriele [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Instituut voor Theoretische Fysica, KU Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2015-09-14
We develop geometric superspace settings to construct arbitrary higher derivative couplings (including R{sup n} terms) in three-dimensional supergravity theories with N≤3 by realising them as conformal supergravity coupled to certain compensators. For all known off-shell supergravity formulations, we construct supersymmetric invariants with up to and including four derivatives. As a warming-up exercise, we first give a new and completely geometric derivation of such invariants in N=1 supergravity. Upon reduction to components, they agree with those given in http://arxiv.org/abs/0907.4658 and http://arxiv.org/abs/1005.3952. We then carry out a similar construction in the case of N=2 supergravity for which there exist two minimal formulations that differ by the choice of compensating multiplet: (i) a chiral scalar multipet; (ii) a vector multiplet. For these formulations all four derivative invariants are constructed in completely general and gauge independent form. For a general supergravity model (in the N=1 and minimal N=2 cases) with curvature-squared and lower order terms, we derive the superfield equations of motion, linearise them about maximally supersymmetric backgrounds and obtain restrictions on the parameters that lead to models for massive supergravity. We use the non-minimal formulation for N=2 supergravity (which corresponds to a complex linear compensator) to construct a novel consistent theory of massive supergravity. In the case of N=3 supergravity, we employ the off-shell formulation with a vector multiplet as compensator to construct for the first time various higher derivative invariants. These invariants may be used to derive models for N=3 massive supergravity. As a bi-product of our analysis, we also present superfield equations for massive higher spin multiplets in (1,0), (1,1) and (2,0) anti-de Sitter superspaces.
International Nuclear Information System (INIS)
Gell-Mann, M.
1985-01-01
The ''standard'' SU/sub 3/ x SU/sub 2/ x U/sub 1/ theory has three independent coupling constants and numerous dimensionless parameters determining mass ratios, the weak coupling matrix, etc. While N=1 supergravity, generalizing Einstein's gravity theory, is not necessarily very divergent itself, it is terribly divergent when coupled to external N=1 supermatter, such as N=1 super-Yang-Mills theory with N=1 supermultiplets of spin one-half and spin zero. Three paths are being explored in the search for the ultimate unified theory of physics. The first path involves N > 1 supergravity in four dimensions, without external supermatter, particularly the largest such theory, N=8 supergravity, where there is no room for external supermatter. The N=8 supergravity supermultiplet itself contains all the haplons (fundamental fields of the theory). During the last couple of years Michael Green and John Schwarz have found that there are two more 10-dimensional superstring theories IIA and IIB, with only closed strings. They reduce, on truncation to the initially massless actor, to N=2A and N=2B supergravity, respectively, in ten dimensions. But the superstring theories are finite to one loop instead of divergent like the corresponding supergravities. The author discusses that IIA and IIB superstrings, when truncated to the initially massless sector and trivially reduced to four dimensions, yield N=8 supergravity. All three superstring theories, although they have the traditional description as ''S-matrix'' theories on the mass shell, can also be written as field theories (with fields as functionals of strings instead of functions of points) with local couplings. So far, the field description is not covariant. This paper discusses various superstrings theories
International Nuclear Information System (INIS)
Grab, Sebastian
2009-08-01
The most widely studied supersymmetric scenario is the minimal supersymmetric standard model (MSSM) with more than a hundred free parameters. However for detailed phenomenological studies, the minimal supergravity (mSUGRA) model, a restricted and well-motivated framework for the MSSM, is more convenient. In this model, lepton- and baryon-number violating interactions are suppressed by a discrete symmetry, R-parity or proton-hexality, to keep the proton stable. However, it is sufficient to forbid only lepton- or baryon-number violation. We thus extend mSUGRA models by adding a proton-hexality violating operator at the grand unification scale. This can change the supersymmetric spectrum leading on the one hand to a sneutrino, smuon or squark as the lightest supersymmetric particle (LSP). On the other hand, a wide parameter region is reopened, where the scalar tau (stau) is the LSP. We investigate in detail the conditions leading to non-neutralino LSP scenarios. We take into account the restrictions from neutrino masses, the muon anomalous magnetic moment, b→sγ, and other precision measurements. We furthermore investigate existing restrictions from direct searches at LEP, the Tevatron, and the CERN p anti p collider. It is vital to know the nature of the LSP, since supersymmetric particles normally cascade decay down to the LSP at collider experiments. We present typical LHC signatures for sneutrino LSP scenarios. Promising signatures are high-p T muons and jets, like-sign muon events and detached vertices from long lived taus. We also classify the stau LSP decays and describe their dependence on the mSUGRA parameters. We then exploit our results for resonant single slepton production at the LHC. We find novel signatures with like-sign muon and three- and four-muon final states. Finally, we perform a detailed analysis for single slepton production in association with a single top quark. We show that the signal can be distinguished from the background at the LHC
Inflation after COBE: Lectures on inflationary cosmology
International Nuclear Information System (INIS)
Turner, M.S.
1992-01-01
In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge-a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for and the fundamentals of inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses the shortcomings of the standard cosmology and provides the ''initial data'' for structure formation. I conclude by addressing the implications of inflation for structure formation, evaluating the various cold dark matter models in the light of the recent detection of temperature anisotropies in the cosmic background radiation by COBE. In the near term, the study of structure formation offers a powerful probe of inflation, as well as specific inflationary models
Inflation after COBE: Lectures on inflationary cosmology
Energy Technology Data Exchange (ETDEWEB)
Turner, M.S. [Chicago Univ., IL (United States). Enrico Fermi Inst.]|[Fermi National Accelerator Lab., Batavia, IL (United States)
1992-12-31
In these lectures I review the standard hot big-bang cosmology, emphasizing its successes, its shortcomings, and its major challenge-a detailed understanding of the formation of structure in the Universe. I then discuss the motivations for and the fundamentals of inflationary cosmology, particularly emphasizing the quantum origin of metric (density and gravity-wave) perturbations. Inflation addresses the shortcomings of the standard cosmology and provides the ``initial data`` for structure formation. I conclude by addressing the implications of inflation for structure formation, evaluating the various cold dark matter models in the light of the recent detection of temperature anisotropies in the cosmic background radiation by COBE. In the near term, the study of structure formation offers a powerful probe of inflation, as well as specific inflationary models.
Yang-Mills-Chern-Simons supergravity
International Nuclear Information System (INIS)
Lue, H; Pope, C N; Sezgin, E
2004-01-01
N = (1, 0) supergravity in six dimensions admits AdS 3 x S 3 as a vacuum solution. We extend our recent results presented in Lue et al (2002 Preprint hep-th/0212323), by obtaining the complete N = 4 Yang-Mills-Chern-Simons supergravity in D = 3, up to quartic fermion terms, by S 3 group manifold reduction of the six-dimensional theory. The SU(2) gauge fields have Yang-Mills kinetic terms as well as topological Chern-Simons mass terms. There is in addition a triplet of matter vectors. After diagonalization, these fields describe two triplets of topologically-massive vector fields of opposite helicities. The model also contains six scalars, described by a GL(3, R)/SO(3) sigma model. It provides the first example of a three-dimensional gauged supergravity that can be obtained by a consistent reduction of string theory or M-theory and that admits AdS 3 as a vacuum solution. There are unusual features in the reduction from six-dimensional supergravity, owing to the self-duality condition on the 3-form field. The structure of the full equations of motion in N = (1, 0) supergravity in D = 6 is also elucidated, and the role of the self-dual field strength as torsion is exhibited
Hidden symmetries in five-dimensional supergravity
International Nuclear Information System (INIS)
Poessel, M.
2003-05-01
This thesis is concerned with the study of hidden symmetries in supergravity, which play an important role in the present picture of supergravity and string theory. Concretely, the appearance of a hidden G 2(+2) /SO(4) symmetry is studied in the dimensional reduction of d=5, N=2 supergravity to three dimensions - a parallel model to the more famous E 8(+8) /SO(16) case in eleven-dimensional supergravity. Extending previous partial results for the bosonic part, I give a derivation that includes fermionic terms. This sheds new light on the appearance of the local hidden symmetry SO(4) in the reduction, and shows up an unusual feature which follows from an analysis of the R-symmetry associated with N=4 supergravity and of the supersymmetry variations, and which has no parallel in the eleven-dimensional case: The emergence of an additional SO(3) as part of the enhanced local symmetry, invisible in the dimensional reduction of the gravitino, and corresponding to the fact that, of the SO(4) used in the coset model, only the diagonal SO(3) is visible immediately upon dimensional reduction. The uncovering of the hidden symmetries proceeds via the construction of the proper coset gravity in three dimensions, and matching it with the Lagrangian obtained from the reduction. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Itoyama, H.; McLerran, L.; Taylor, T.R.; Van der Bij, J.J.
1987-01-12
N=2 extended supergravity is discussed and an assessment is made of the problems encountered in applying it to the construction of phenomenological models of particle physics. A specific class of so-called no-scale models is discussed, in which the two supersymmetries are spontaneously broken in flat space-time, with naturally vanishing cosmological constant and the symmetry breaking undetermined at the classical level. Supergravity-induced supersymmetry breaking generates effective mass terms for spin-1/2 components of the vector gauge multiplets and spin-0 components of the scalar matter multiplets. For finite globally supersymmetric models, this supersymmetry breaking preserves the finiteness. Possible connections of N=2 no-scale supergravity with superstrings and finite range antigravity are mentioned.
International Nuclear Information System (INIS)
Itoyama, H.; McLerran, L.; Taylor, T.R.; Van der Bij, J.J.
1987-01-01
N=2 extended supergravity is discussed and an assessment is made of the problems encountered in applying it to the construction of phenomenological models of particle physics. A specific class of so-called no-scale models is discussed, in which the two supersymmetries are spontaneously broken in flat space-time, with naturally vanishing cosmological constant and the symmetry breaking undetermined at the classical level. Supergravity-induced supersymmetry breaking generates effective mass terms for spin-1/2 components of the vector gauge multiplets and spin-0 components of the scalar matter multiplets. For finite globally supersymmetric models, this supersymmetry breaking preserves the finiteness. Possible connections of N=2 no-scale supergravity with superstrings and finite range antigravity are mentioned. (orig.)
The antigravitation phenomenon in supergravity theories
International Nuclear Information System (INIS)
Kotrla, M.
1984-01-01
The supergravity theories describe the interaction of particles by means of the local field theory, contain the gravitational field and are invariant relative to local supersymmetry. In supergravity models gravitational interaction is mediated not only by the usual tensor field with spin two but also by a vector field and possibly by a scalar field. This results in the fact that in supergravity theories the gravitational force between a particle and an antiparticle may increase over small distances, and the gravitational force between two particles or two antiparticles may disappear. The properties of the model may be summed up by saying that the model is generally covariant but leads to the disturbance of the weak principle of equivalence, the gravitational law differs from Newton's law at small distances, and particles and antiparticles do not have the same mass. (B.S.)
Fluctuations of inflationary magnetogenesis
Giovannini, Massimo
2013-01-01
This analysis aims at exploring what can be said about the growth rate of magnetized inhomogeneities under two concurrent hypotheses: a phase of quasi-de Sitter dynamics driven by a single inflaton field and the simultaneous presence of a spectator field coupled to gravity and to the gauge sector. Instead of invoking ad hoc correlations between the various components, the system of scalar inhomogeneities is diagonalized in terms of two gauge-invariant quasi-normal modes whose weighted sum gives the curvature perturbations on comoving orthogonal hypersurfaces. The predominance of the conventional adiabatic scalar mode implies that the growth rate of magnetized inhomogeneities must not exceed 2.2 in Hubble units if the conventional inflationary phase is to last about 70 efolds and for a range of slow roll parameters between 0.1 and 0.001. Longer and shorter durations of the quasi-de Sitter stage lead, respectively, either to tighter or to looser bounds which are anyway more constraining than the standard backre...
Effective Lagrangian for s-barbg and s-barbγ vertices in the minimal supergravity model
International Nuclear Information System (INIS)
Feng Taifu; Li Xueqian; Wang Guoli
2002-01-01
Complete expressions of the s-barbg and s-barbγ vertices are derived in the framework of supersymmetry with minimal flavor violation. As examples, the branching ratios of charmless B decays [B→K+X (no charm)] and exclusive processes B s →γγ are calculated with the minimal supergravity assumptions
Are inflationary predictions sensitive to very high energy physics?
International Nuclear Information System (INIS)
Burgess, C.P.; Lemieux, F.; Holman, R.; Cline, J.M.
2003-01-01
It has been proposed that the successful inflationary description of density perturbations on cosmological scales is sensitive to the details of physics at extremely high (trans-Planckian) energies. We test this proposal by examining how inflationary predictions depend on higher-energy scales within a simple model where the higher-energy physics is well understood. We find the best of all possible worlds: inflationary predictions are robust against the vast majority of high-energy effects, but can be sensitive to some effects in certain circumstances, in a way which does not violate ordinary notions of decoupling. This implies both that the comparison of inflationary predictions with CMB data is meaningful, and that it is also worth searching for small deviations from the standard results in the hopes of learning about very high energies. (author)
Massive type IIA supergravity and E10
International Nuclear Information System (INIS)
Henneaux, M.; Kleinschmidt, A.; Persson, D.; Jamsin, E.
2009-01-01
In this talk we investigate the symmetry under E 10 of Romans' massive type IIA supergravity. We show that the dynamics of a spinning particle in a non-linear sigma model on the coset space E 10 /K(E 10 ) reproduces the bosonic and fermionic dynamics of massive IIA supergravity, in the standard truncation. In particular, we identify Romans' mass with a generator of E 10 that is beyond the realm of the generators of E 10 considered in the eleven-dimensional analysis, but using the same, underformed sigma model. As a consequence, this work provides a dynamical unification of the massless and massive versions of type IIA supergravity inside E 10 . (Abstract Copyright [2009], Wiley Periodicals, Inc.)
Inflaton decay through supergravity effects
International Nuclear Information System (INIS)
Endo, M.; Takahashi, F.; Kawasaki, M.; Yanagida, T.T.; Tokyo Univ.
2006-07-01
We point out that supergravity effects enable the inflaton to decay into all matter fields, including the visible and the supersymmetry breaking sectors, once the inflaton acquires a non-vanishing vacuum expectation value. The new decay processes have great impacts on cosmology; the reheating temperature is bounded below; the gravitinos are produced by the inflaton decay in a broad class of the dynamical supersymmetry breaking models. We derive the bounds on the inflaton mass and the vacuum expectation value, which severely constrain high-scale inflations such as the hybrid and chaotic inflation models. (orig.)
Classical solutions and extended supergravity
International Nuclear Information System (INIS)
de Alfaro, V.; Fubini, S.; Furlan, G.
1980-03-01
The existence and properties of classical solutions for gravity coupled to matter fields have been investigated previously with the limitation to conformally flat solutions. In the search for a guiding criterion to determine the form of the coupling among the fields, one is led to consider supersymmetric theories, and the question arises whether classical solutions persist in these models. It is found that a discrepancy persists between supergravity and standard meron solutions. Owing to the appearance of the scalar field, a new set of meron solutions exists for particular Lagrangian models. In conclusion, the form of solutions in Minkowski space is discussed
Bagchi, Arjun; Basu, Rudranil; Detournary, Stéphane; Parekh, Pulastya
2018-05-01
We propose a holographic duality between a 2 dimensional (2d) chiral superconformal field theory and a certain theory of supergravity in 3d with flatspace boundary conditions that is obtained as a double scaling limit of a parity breaking theory of supergravity. We show how the asymptotic symmetries of the bulk theory reduce from the "despotic" super Bondi-Metzner-Sachs algebra (or equivalently the inhomogeneous super Galilean conformal algebra) to a single copy of the super-Virasoro algebra in this limit and also reproduce the same reduction from a study of null vectors in the putative 2d dual field theory.
Null cone superspace supergravity
International Nuclear Information System (INIS)
Downes-Martin, S.G.
1980-03-01
The null cone formalism is used to derive a 2(N-1) parameter family of constraints for O(N) extended superspace supergravity. The invariance groups of these constraints is analysed and is found to be [subgroup U submanifold] contains GL(4,R) for N = 1, the submanifold being eliminated for N > 1. The invariance group defines non-Weyl rotations on the superbein which combine to form Weyl transformations on the supertangent space metric. The invariance of the supergravity Lagrangian under these transformations is discussed. (Auth.)
Quantum supergravity, supergravity anomalies and string phenomenology
Energy Technology Data Exchange (ETDEWEB)
Gaillard, Mary K., E-mail: mkgaillard@lbl.gov
2016-11-15
I discuss the role of quantum effects in the phenomenology of effective supergravity theories from compactification of the weakly coupled heterotic string. An accurate incorporation of these effects requires a regularization procedure that respects local supersymmetry and BRST invariance and that retains information associated with the cut-off scale, which has physical meaning in an effective theory. I briefly outline the Pauli–Villars regularization procedure, describe some applications, and comment on what remains to be done to fully define the effective quantum field theory.
Eternally existing self-reproducing inflationary universe
International Nuclear Information System (INIS)
Linde, A.D.
1986-05-01
It is shown that the large-scale quantum fluctuations of the scalar field φ generated in the chaotic inflation scenario lead to an infinite process of self-reproduction of inflationary mini-universes. A model of eternally existing chaotic inflationary universe is suggested. It is pointed out that whereas the universe locally is very homogeneous as a result of inflation, which occurs at the classical level, the global structure of the universe is determined by quantum effects and is highly non-trivial. The universe consists of exponentially large number of different mini-universes, inside which all possible (metastable) vacuum states and all possible types of compactification are realized. The picture differs crucially from the standard picture of a one-domain universe in a ''true'' vacuum state. Our results may serve as a justification of the anthropic principle in the inflationary cosmology. These results may have important implications for the elementary particle theory as well. Namely, since all possible types of mini-universes, in which inflation may occur, should exist in our universe, there is no need to insist (as it is usually done) that in realistic theories the vacuum state of our type should be the only possible one or the best one. (author)
Spontaneous symmetry breaking in N = 2 supergravity
International Nuclear Information System (INIS)
Zinov'ev, Y.M.
1987-01-01
A model describing the interaction of N = 2 supergravity with a vector and a linear multiplet is constructed. The model admits the introduction of spontaneous supersymmetry breaking with two arbitrary scales, one of which can be equal to zero, corresponding to the partial super-Higgs effect (N = 2→N = 1). The cosmological term is automatically equal to zero
No-scale supergravity and cosmology
International Nuclear Information System (INIS)
Deruelle, N.
1988-01-01
The confrontation of current unified theories with cosmoly may prove to be very fruteful. Indeed the demand that the cosmological models they induce match the standard scenario and be free of manifest pathologies imposes severe constraints on them. We thus show that no-scale supergravity (at least its simplest incarnation) may not provide acceptable models of the early universe [fr
The Wasteland of Random Supergravities
Marsh, David; McAllister, Liam; Wrase, Timm
2011-01-01
We show that in a general \\cal{N} = 1 supergravity with N \\gg 1 scalar fields, an exponentially small fraction of the de Sitter critical points are metastable vacua. Taking the superpotential and Kahler potential to be random functions, we construct a random matrix model for the Hessian matrix, which is well-approximated by the sum of a Wigner matrix and two Wishart matrices. We compute the eigenvalue spectrum analytically from the free convolution of the constituent spectra and find that in ...
Topics in supergravity and string theory
International Nuclear Information System (INIS)
Eastaugh, A.G.
1987-01-01
The first topic covered in this dissertation concerns the harmonic expansion technique and its application to the dimensional compactification of higher dimensional supergravity. A simple example is given to explain the method and then the method is applied to the problem of obtaining the mass spectrum of the squashed seven-sphere compactification of eleven dimensional supergravity. The second topic concerns the application of Fujikawa's method of anomaly calculation to the calculation of the critical dimension of various string models. The third topic is a study and explicit calculation of the Fock space representation of the vertex in Witten's formulation of the interacting open bosonic string field theory
Off-shell Poincaré supergravity
Energy Technology Data Exchange (ETDEWEB)
Freedman, Daniel Z. [SITP and Department of Physics, Stanford University,Stanford, California 94305 (United States); Center for Theoretical Physics and Department of Mathematics,Massachusetts Institute of Technology,Cambridge, Massachusetts 02139 (United States); Roest, Diederik [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Proeyen, Antoine Van [KU Leuven, Institute for Theoretical Physics,Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2017-02-21
We present the action and transformation rules of Poincaré supergravity coupled to chiral multiplets (z{sup α},χ{sup α},h{sup α}) with off-shell auxiliary fields. Starting from the geometric formulation of the superconformal theory with auxiliary fields, we derive the Poincaré counterpart by gauge-fixing the Weyl and chiral symmetry and S-supersymmetry. We show how this transition is facilitated by retaining explicit target-space covariance. Our results form a convenient starting point to study models with constrained superfields, including general matter-coupled de Sitter supergravity.
D=3 unification of curious supergravities
Energy Technology Data Exchange (ETDEWEB)
Duff, M.J. [Theoretical Physics, Blackett Laboratory, Imperial College London,London SW7 2AZ (United Kingdom); Mathematical Institute University of Oxford, Andrew Wiles Building,Woodstock Road, Radcliffe Observatory Quarter, Oxford, OX2 6GG (United Kingdom); Ferrara, S. [Theoretical Physics Department, CERN,CH-1211 Geneva (Switzerland); INFN - Laboratori Nazionali di Frascati,Via Enrico Fermi 40, I-00044 Frascati (Italy); Department of Physics and Astronomy andMani L. Bhaumik Institute for Theoretical Physics, UCLA,Los Angeles CA 90095-1547 (United States); Marrani, A. [Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”,Via Panisperna 89A, I-00184, Roma (Italy); Dipartimento di Fisica e Astronomia “Galileo Galilei”,Università di Padova and INFN, Sez. di Padova,Via Marzolo 8, I-35131 Padova (Italy); Theoretical Physics Department, CERN,CH-1211 Geneva (Switzerland)
2017-01-09
We consider the dimensional reduction to D=3 of four maximal-rank supergravities which preserve minimal supersymmetry in D=11, 7, 5 and 4. Such “curious” theories were investigated some time ago, and the four-dimensional one corresponds to an N=1 supergravity with 7 chiral multiplets spanning the seven-disk manifold. Recently, this latter theory provided cosmological models for α-attractors, which are based on the disk geometry with possible restrictions on the parameter α. A unified picture emerges in D=3, where the Ehlers group of General Relativity merges with the S-, T- and U- dualities of the D=4 parent theories.
D = 3 Unification of Curious Supergravities
Duff, M.J.; Marrani, A.
2017-01-09
We consider the dimensional reduction to D = 3 of four maximal-rank supergravities which preserve minimal supersymmetry in D = 11, 7, 5 and 4. Such "curious" theories were investigated some time ago, and the four-dimensional one corresponds to an N = 1 supergravity with 7 chiral multiplets spanning the seven-disk manifold. Recently, this latter theory was considered to provide cosmological models for alpha-attractors, which are based on the disk geometry with possible restrictions on the parameter alpha. A unified picture emerges in D = 3, where the Ehlers group of General Relativity merges with the S-, T- and U- dualities of the D = 4 parent theories.
Energy Technology Data Exchange (ETDEWEB)
Grab, Sebastian
2009-08-15
The most widely studied supersymmetric scenario is the minimal supersymmetric standard model (MSSM) with more than a hundred free parameters. However for detailed phenomenological studies, the minimal supergravity (mSUGRA) model, a restricted and well-motivated framework for the MSSM, is more convenient. In this model, lepton- and baryon-number violating interactions are suppressed by a discrete symmetry, R-parity or proton-hexality, to keep the proton stable. However, it is sufficient to forbid only lepton- or baryon-number violation. We thus extend mSUGRA models by adding a proton-hexality violating operator at the grand unification scale. This can change the supersymmetric spectrum leading on the one hand to a sneutrino, smuon or squark as the lightest supersymmetric particle (LSP). On the other hand, a wide parameter region is reopened, where the scalar tau (stau) is the LSP. We investigate in detail the conditions leading to non-neutralino LSP scenarios. We take into account the restrictions from neutrino masses, the muon anomalous magnetic moment, b{yields}s{gamma}, and other precision measurements. We furthermore investigate existing restrictions from direct searches at LEP, the Tevatron, and the CERN p anti p collider. It is vital to know the nature of the LSP, since supersymmetric particles normally cascade decay down to the LSP at collider experiments. We present typical LHC signatures for sneutrino LSP scenarios. Promising signatures are high-p{sub T} muons and jets, like-sign muon events and detached vertices from long lived taus. We also classify the stau LSP decays and describe their dependence on the mSUGRA parameters. We then exploit our results for resonant single slepton production at the LHC. We find novel signatures with like-sign muon and three- and four-muon final states. Finally, we perform a detailed analysis for single slepton production in association with a single top quark. We show that the signal can be distinguished from the background
Moduli backreaction on inflationary attractors
International Nuclear Information System (INIS)
Roest, Diederik; Werkman, Pelle
2016-07-01
We investigate the interplay between moduli dynamics and inflation, focusing on the KKLT- scenario and cosmological α-attractors. General couplings between these sectors can induce a significant backreaction and potentially destroy the inflationary regime; however, we demonstrate that this generically does not happen for α-attractors. Depending on the details of the superpotential, the volume modulus can either be stable during the entire inflationary trajectory, or become tachyonic at some point and act as a waterfall field, resulting in a sudden end of inflation. In the latter case there is a universal supersymmetric minimum where the scalars end up, preventing the decompactification scenario. The gravitino mass is independent from the inflationary scale with no fine-tuning of the parameters. The observational predictions conform to the universal value of attractors, fully compatible with the Planck data, with possibly a capped number of e-folds due to the interplay with moduli.
Post-inflationary brane cosmology
International Nuclear Information System (INIS)
Mazumdar, Anupam
2001-01-01
The brane cosmology has invoked new challenges to the usual Big Bang cosmology. In this paper we present a brief account on thermal history of the post-inflationary brane cosmology. We have realized that it is not obvious that the post-inflationary brane cosmology would always deviate from the standard Big Bang cosmology. However, if it deviates some stringent conditions on the brane tension are to be satisfied. In this regard we study various implications on gravitino production and its abundance. We discuss Affleck-Dine mechanism for baryogenesis and make some comments on moduli and dilaton problems in this context
Inflationary implications of supersymmetry breaking
Borghese, Andrea; Roest, Diederik; Zavala, Ivonne
2013-01-01
We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll
De Sitter vacua in no-scale supergravities and Calabi-Yau string models
Covi, Laura; Gross, Christian; Louis, Jan; Palma, Gonzalo A; Scrucca, Claudio A
2008-01-01
We perform a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N=1 supersymmetry and non-negative cosmological constant in the moduli sector of string models. More specifically, we study the condition under which the scalar partners of the Goldstino are non-tachyonic, which depends only on the Kahler potential. This condition is not only necessary but also sufficient, in the sense that all of the other scalar fields can be given arbitrarily large positive square masses if the superpotential is suitably tuned. We consider both heterotic and orientifold string compactifications in the large-volume limit and show that the no-scale property shared by these models severely restricts the allowed values for the `sGoldstino' masses in the superpotential parameter space. We find that a positive mass term may be achieved only for certain types of compactifications and specific Goldstino directions. Additionally, we show how subleading corrections to the Kahler potential which b...
Baryogenesis in an inflationary universe
International Nuclear Information System (INIS)
Dodelson, S.
1988-01-01
The existence of matter in our universe today is a result of fundamental processes in the early universe. This matter is the remnant of an asymmetry between matter and anti-matter. How that asymmetry developed is the focus of this thesis. A statistical mechanical analysis is given of baryogenesis after an inflationary era
Reconstructing inflationary paradigm within Effective Field Theory framework
Choudhury, Sayantan
2016-03-01
In this paper my prime objective is to analyse the constraints on a sub-Planckian excursion of a single inflaton field within Effective Field Theory framework in a model independent fashion. For a generic single field inflationary potential, using the various parameterization of the primordial power spectrum I have derived the most general expression for the field excursion in terms of various inflationary observables, applying the observational constraints obtained from recent Planck 2015 and Planck 2015 + BICEP2/Keck Array data. By explicit computation I have reconstructed the structural form of the inflationary potential by constraining the Taylor expansion co-efficients appearing in the generic expansion of the potential within the Effective Field Theory. Next I have explicitly derived, a set of higher order inflationary consistency relationships, which would help us to break the degeneracy between various class of inflationary models by differentiating them. I also provided two simple examples of Effective Theory of inflation- inflection-point model and saddle-point model to check the compatibility of the prescribed methodology in the light of Planck 2015 and Planck 2015 + BICEP2/Keck Array data. Finally, I have also checked the validity of the prescription by estimating the cosmological parameters and fitting the theoretical CMB TT, TE and EE angular power spectra with the observed data within the multipole range 2 < l < 2500.
de Sitter vacua in no-scale supergravities and Calabi-Yau string models
International Nuclear Information System (INIS)
Covi, L.; Gross, C.; Scrucca, C.A.
2008-04-01
We perform a general analysis on the possibility of obtaining metastable vacua with spontaneously broken N = 1 supersymmetry and non-negative cosmological constant in the moduli sector of string models. More specifically, we study the condition under which the scalar partners of the Goldstino are non-tachyonic, which depends only on the Kaehler potential. This condition is not only necessary but also sufficient, in the sense that all of the other scalar fields can be given arbitrarily large positive square masses if the superpotential is suitably tuned. We consider both heterotic and orientifold string compactifications in the large-volume limit and show that the no-scale property shared by these models severely restricts the allowed values for the 'sGoldstino' masses in the superpotential parameter space. We find that a positive mass term may be achieved only for certain types of compactifications and specific Goldstino directions. Additionally, we show how subleading corrections to the Kaehler potential which break the no-scale property may allow to lift these masses. (orig.)
International Nuclear Information System (INIS)
Isenberg, J.; Bao, D.; Yasskin, P.B.
1983-01-01
One rather fundamental question concerning supergravity remains unresolved: Is supergravity a well-posed field theory? That is, does a set of certain (Cauchy) data specified on some initial spacelike surface determine a unique, causally propagating spacetime solution of the supergravity field equations (at least in some finite neighborhood of the initial surface)? In this paper, the authors give a very brief report on work directed towards answering this question. (Auth.)
Grand unification and supergravity
International Nuclear Information System (INIS)
Nanopoulos, D.V.
Grand Unified Theories (GUTs) are very successful, but they suffer from fine-tuning or hierarchy problems. It seems that more symmetry beyond the gauge symmetry is needed and indeed supersymmetric GUTs may provide the correct framework in solving the hierarchy problems. These are reviewed. From the results discussed, it is seen that for the first time in particle physics, gravity seems to play a dominant role. It may be responsible for GUT breaking, SU(2) x U(1) breaking, fermion masses, proton decay and a consistent cosmological picture. Supergravity seems to offer a consistent, effective theory for energies below the Planck scale to N=1 local SUSY but also, in the context of N=8 extended supergravity with a dynamically realized SU(8), there may be a consistent fundamental unified theory of all interactions. (U.K.)
Direct detection of the inflationary gravitational-wave background
International Nuclear Information System (INIS)
Smith, Tristan L.; Kamionkowski, Marc; Cooray, Asantha
2006-01-01
Inflation generically predicts a stochastic background of gravitational waves over a broad range of frequencies, from those accessible with cosmic microwave background (CMB) measurements, to those accessible directly with gravitational-wave detectors, like NASA's Big-Bang Observer (BBO) or Japan's Deci-Hertz Interferometer Gravitational-wave Observer (DECIGO), both currently under study. Here we investigate the detectability of the inflationary gravitational-wave background at BBO/DECIGO frequencies. To do so, we survey a range of slow-roll inflationary models consistent with constraints from the CMB and large-scale structure (LSS). We go beyond the usual assumption of power-law power spectra, which may break down given the 16 orders of magnitude in frequency between the CMB and direct detection, and solve instead the inflationary dynamics for four classes of inflaton potentials. Direct detection is possible in a variety of inflationary models, although probably not in any in which the gravitational-wave signal does not appear in the CMB polarization. However, direct detection by BBO/DECIGO can help discriminate between inflationary models that have the same slow-roll parameters at CMB/LSS scales
Covariant field equations in supergravity
Energy Technology Data Exchange (ETDEWEB)
Vanhecke, Bram [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium); Ghent University, Faculty of Physics, Gent (Belgium); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)
2017-12-15
Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Covariant field equations in supergravity
International Nuclear Information System (INIS)
Vanhecke, Bram; Proeyen, Antoine van
2017-01-01
Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
International Nuclear Information System (INIS)
Wit, B. de; Lauwers, P.G.; Philippe, R.; Van Proeyen, A.
1983-10-01
A massive spin-1 multiplet with central charge is coupled to N=2 supergravity. Compared to conventional gauge fields the anomalous magnetic moment of the spin-1 particles is of opposite sign. The construction of this theory is based on an N=2 supersymmetric gauge theory associated with the noncompact group SO(2,1). As a byproduct we present a convenient expression for the N=2 Einstein-Yang-Mills lagrangian. (Auth.)
Two exercises in supersymmetry: a low-energy supergravity model and free string field theory
International Nuclear Information System (INIS)
Preitschopf, C.R.
1986-09-01
The new features of a supersymmetric standard model in the presence of heavy families are studied. The minimal set of Higgs fields, the desert between the electroweak and the grand unification scale and perturbative values of the dimensionless parameters throughout this region are assumed. Using the numerical as well as the approximate analytic solution of the renormalization group equations, the evolution of all the parameters of the theory are studied in the case of large Yukawa couplings for the fourth family. The desired spontaneous symmetry breaking of the electroweak symmetry takes place only for a rather unnatural choice of the initial values of certain mass parameters at the grand unification scale. If it is gravitino mass smaller than 200 GeV the vacuum expectation values of the Higgs fields emerge necessarily in an interplay of the tree level Higgs potential and its quantum corrections and are approximately equal. The qurak masses of the fourth family are roughly 135 GeV, while the mass of the fourth charged lepton has an upper bound of 90 GeV. Further characteristic features of this scenario are one light neutral Higgs field of mass 50 GeV and gluino masses below 75 GeV. If the gravitino mass is higher than 200 GeV one obtains a scaled up version of the well-known three family, heavy top scenario with quark masses between 40 and 205 GeV and all superparticle masses heavier than 150 GeV except the photino, gluino, one chargino and one neutralino. The gauge-invariant theory of the free bosonic open string is generalized to treat closed strings and superstrings. All of these theories can be written as theories of string differential forms defined on suitable spaces. All of the bosonic theories have exactly the same structure; the Ramond theory takes an analogous first-order form. We show explicitly, how to gauge-fix each action to the light-cone gauge and to the Feynman-Siegel gauge
Massive Supergravity and Deconstruction
Gregoire, T; Shadmi, Y; Gregoire, Thomas; Schwartz, Matthew D; Shadmi, Yael
2004-01-01
We present a simple superfield Lagrangian for massive supergravity. It comprises the minimal supergravity Lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli Lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show that the on-shell bosonic and fermionic fields are degenerate and have the appropriate spins: 2, 3/2, 3/2 and 1. We then study this interacting Lagrangian using goldstone superfields. We find that a chiral multiplet of goldstones gets a kinetic term through mixing, just as the scalar goldstone does in the non-supersymmetric case. This produces Planck scale (Mpl) interactions with matter and all the discontinuities and unitarity bounds associated with massive gravity. In particular, the scale of strong coupling is (Mpl m^4)^1/5, where m is the multiplet's mass. Next, we consider applications of massive supergravity to deconstruction. We estimate various qu...
Newton-Cartan supergravity with torsion and Schrodinger supergravity
Bergshoeff, Eric; Rosseel, Jan; Zojer, Thomas
2015-01-01
We derive a torsionfull version of three-dimensional N - 2 Newton-Cartan supergravity using a non-relativistic notion of the superconformal tensor calculus. The "superconformal" theory that we start with is Schrodinger supergravity which we obtain by gauging the Schrodinger superalgebra. We present
Reconstructing a general inflationary action
International Nuclear Information System (INIS)
Bean, Rachel; Chung, Daniel J. H.; Geshnizjani, Ghazal
2008-01-01
If inflation is to be considered in an unbiased way, as possibly originating from one of a wide range of underlying theories, then observations need not be simply applied to reconstructing the inflaton potential V(φ) or a specific kinetic term, as in Dirac-Born-Infeld inflation, but rather to reconstruct the inflationary action in its entirety. We discuss the constraints that can be placed on a general single field action from measurements of the primordial scalar and tensor fluctuation power spectra and non-Gaussianities. The analytic form of the action that is consistent with data turns out to be surprisingly simple and easy to categorize. We also present the flow equation formalism for reconstructing a general inflationary Lagrangian L(X,φ), with X=(1/2)∂ μ φ∂ μ φ, in a general gauge, that reduces to canonical and DBI inflation in the specific gauge L X =c s -1 .
Moduli Backreaction on Inflationary Attractors
Roest, Diederik; Werkman, Pelle
2016-01-01
We investigate the interplay between moduli dynamics and inflation, focusing on the KKLT-scenario and cosmological $\\alpha$-attractors. General couplings between these sectors can induce a significant backreaction and potentially destroy the inflationary regime; however, we demonstrate that this generically does not happen for $\\alpha$-attractors. Depending on the details of the superpotential, the volume modulus can either be stable during the entire inflationary trajectory, or become tachyonic at some point and act as a waterfall field, resulting in a sudden end of inflation. In the latter case there is a universal supersymmetric minimum where the scalars end up, preventing the decompactification scenario. The observational predictions conform to the universal value of attractors, fully compatible with the Planck data, with possibly a capped number of e-folds due to the interplay with moduli.
Pole inflation in Jordan frame supergravity
Energy Technology Data Exchange (ETDEWEB)
Saikawa, Ken' ichi [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yamaguchi, Masahide [Tokyo Institute of Technology, Ookayama (Japan). Dept. of Physics; Yamashita, Yasuho [Kyoto Univ. (Japan). Yukawa Inst. for Theoretical Physics; Yoshida, Daisuke [Montreal Univ., QC (Canada). Dept. of Physics
2017-09-15
We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we construct inflation models with asymptotically flat potential through pole inflation technique and discuss their relation to the models based on Einstein frame supergravity. We also show that the model proposed by Ferrara et al. has special position and the relation between the Kaehler potential and the frame function is uniquely determined by requiring that scalars take the canonical kinetic terms in the Jordan frame and that a frame function consists only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry breaking terms. Our case corresponds to relaxing the latter condition.
Pole inflation in Jordan frame supergravity
International Nuclear Information System (INIS)
Saikawa, Ken'ichi; Yamaguchi, Masahide; Yamashita, Yasuho; Yoshida, Daisuke
2017-09-01
We investigate inflation models in Jordan frame supergravity, in which an inflaton non-minimally couples to the scalar curvature. By imposing the condition that an inflaton would have the canonical kinetic term in the Jordan frame, we construct inflation models with asymptotically flat potential through pole inflation technique and discuss their relation to the models based on Einstein frame supergravity. We also show that the model proposed by Ferrara et al. has special position and the relation between the Kaehler potential and the frame function is uniquely determined by requiring that scalars take the canonical kinetic terms in the Jordan frame and that a frame function consists only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry breaking terms. Our case corresponds to relaxing the latter condition.
New compactifications in seven and eleven dimensional supergravity theories
International Nuclear Information System (INIS)
Pernici, M.; Sezgin, E.
1984-08-01
It is found that the N=4 gauged supergravity in d=7 spontaneously compactifies on direct product of anti-deSitter space (AdS) with a 3-sphere (non-supersymmetric: N=0), or with 3-hyperboloid (N=2). Similarly the N=2 gauged supergravity in d=7 compactifies on AdSxH 3 (N=1). The possibility of σ-model induced compactification of ungauged d=7 N=2 supergravity coupled to one vector multiplet on (Minkowski) 4 x Tear Drop x S 1 is discussed. The case of d=11 supergravity is also studied, and two new compactifications are found: AdS x non-Einstein squashed S 7 (n=0) and AdS x non-Einstein SU(2) bundle over CP 2 (N=0). (author)
Topologically massive supergravity
Directory of Open Access Journals (Sweden)
S. Deser
1983-01-01
Full Text Available The locally supersymmetric extension of three-dimensional topologically massive gravity is constructed. Its fermionic part is the sum of the (dynamically trivial Rarita-Schwinger action and a gauge-invariant topological term, of second derivative order, analogous to the gravitational one. It is ghost free and represents a single massive spin 3/2 excitation. The fermion-gravity coupling is minimal and the invariance is under the usual supergravity transformations. The system's energy, as well as that of the original topological gravity, is therefore positive.
Constructive approach to supergravity
International Nuclear Information System (INIS)
Milton, K.A.; Urrutia, L.F.; Finkelstein, R.J.
1980-01-01
Starting from a first-order formulation of the Lagrangian of noninteracting massless helicity-2 and helicity-3/2 particles, global supersymmetry transformations are deduced. Then, allowing the supersymmetry transformations to become local requires, if supersymmetry is to be maintained, the introduction of a unique primitive interaction through the 'gravitino' stress tensor and torsion. Finally, the imposition of exact supersymmetry invariance leads by a short, constructive process to full supergravity and the complete form of the super-symmetry transformations. In particular, no explicit use is made of general coordinate invariance, and the self-consistency of the gravitational coupling emerges from the local supersymmetry requirement alone. (author)
Post-inflationary gravitino production revisited
Energy Technology Data Exchange (ETDEWEB)
Ellis, John [Theoretical Particle Physics and Cosmology Group, Department of Physics, King' s College London, London WC2R 2LS (United Kingdom); Garcia, Marcos A.G.; Olive, Keith A. [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States); Nanopoulos, Dimitri V. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Peloso, Marco, E-mail: john.ellis@cern.ch, E-mail: garciagarcia@physics.umn.edu, E-mail: dimitri@physics.tamu.edu, E-mail: olive@physics.umn.edu, E-mail: peloso@physics.umn.edu [School of Physics and Astronomy and Minnesota Institute for Astrophysics, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)
2016-03-01
We revisit gravitino production following inflation. As a first step, we review the standard calculation of gravitino production in the thermal plasma formed at the end of post-inflationary reheating when the inflaton has completely decayed. Next we consider gravitino production prior to the completion of reheating, assuming that the inflaton decay products thermalize instantaneously while they are still dilute. We then argue that instantaneous thermalization is in general a good approximation, and also show that the contribution of non-thermal gravitino production via the collisions of inflaton decay products prior to thermalization is relatively small. Our final estimate of the gravitino-to-entropy ratio is approximated well by a standard calculation of gravitino production in the post-inflationary thermal plasma assuming total instantaneous decay and thermalization at a time t ≅ 1.2/Γ{sub φ}. Finally, in light of our calculations, we consider potential implications of upper limits on the gravitino abundance for models of inflation, with particular attention to scenarios for inflaton decays in supersymmetric Starobinsky-like models.
Inflationary perturbations in no-scale theories
Energy Technology Data Exchange (ETDEWEB)
Salvio, Alberto [CERN, Theoretical Physics Department, Geneva (Switzerland)
2017-04-15
We study the inflationary perturbations in general (classically) scale-invariant theories. Such scenario is motivated by the hierarchy problem and provides natural inflationary potentials and dark matter candidates. We analyse in detail all sectors (the scalar, vector and tensor perturbations) giving general formulae for the potentially observable power spectra, as well as for the curvature spectral index n{sub s} and the tensor-to-scalar ratio r. We show that the conserved Hamiltonian for all perturbations does not feature negative energies even in the presence of the Weyl-squared term if the appropriate quantisation is performed and argue that this term does not lead to phenomenological problems at least in some relevant setups. The general formulae are then applied to a concrete no-scale model, which includes the Higgs and a scalar, ''the planckion'', whose vacuum expectation value generates the Planck mass. Inflation can be triggered by a combination of the planckion and the Starobinsky scalar and we show that no tension with observations is present even in the case of pure planckion inflation, if the coefficient of the Weyl-squared term is large enough. In general, even quadratic inflation is allowed in this case. Moreover, the Weyl-squared term leads to an isocurvature mode, which currently satisfies the observational bounds, but it may be detectable with future experiments. (orig.)
Gauged Supergravities and Spontaneous Supersymmetry Breaking from the Double Copy Construction
Chiodaroli, M.; Günaydin, M.; Johansson, H.; Roiban, R.
2018-04-01
Supergravities with gauged R symmetry and Minkowski vacua allow for spontaneous supersymmetry breaking and, as such, provide a framework for building supergravity models of phenomenological relevance. In this Letter, we initiate the study of double copy constructions for these supergravities. We argue that, on general grounds, we expect their scattering amplitudes to be described by a double copy of the type (spontaneously broken gauge theory)⊗ (gauge theory with broken supersymmetry). We present a simple realization in which the resulting supergravity has U (1 )R gauge symmetry, spontaneously broken N =2 supersymmetry, and massive gravitini. This is the first instance of a double copy construction of a gauged supergravity and of a theory with spontaneously broken supersymmetry. The construction extends in a straightforward manner to a large family of gauged Yang-Mills-Einstein supergravity theories with or without spontaneous gauge-symmetry breaking.
Structure of a supergravity group
International Nuclear Information System (INIS)
Ogievetsky, V.; Sokatchev, E.
1978-01-01
The supergravity group is found to be the direct product of general covariance groups in complex conjugated left and right handed superspaces. The ordinary space-time coordinate and the axial gravitational superfield are the real and imaginary parts of the complex coordinate, respectively. It is pointed out that a number of questions concerning the formalism remains open. For instance how to define superfields with external indices, supercovariant derivatives and invariants of the group, etc. However, the extremely simple and clear geometrical picture of the supergravity group given here will provide an adequate basis for the supergravity theory
Supergravity and field space democracy
International Nuclear Information System (INIS)
Gayduk, A.V.; Romanov, V.N.; Schwarz, A.S.
1980-01-01
Supergravity is presented in which field and space variables are on an equal footing. The action functional of supergravity is characterized as the functional, defined on the space of (4,4)-dimensional submanifolds of complex (4,2)-dimensional superspace, which is invariant with respect to supervolume preserving analytic transformations. It is shown how the Lagrangian of the supergravity in the Ogievetsky-Sokatchev form can be obtained by means of this characterization and describe natural multi-dimensional generalizations of this Lagrangian. These generalizations are based on the notion of perfect action functional
Background metric in supergravity theories
International Nuclear Information System (INIS)
Yoneya, T.
1978-01-01
In supergravity theories, we investigate the conformal anomaly of the path-integral determinant and the problem of fermion zero modes in the presence of a nontrivial background metric. Except in SO(3) -invariant supergravity, there are nonvanishing conformal anomalies. As a consequence, amplitudes around the nontrivial background metric contain unpredictable arbitrariness. The fermion zero modes which are explicitly constructed for the Euclidean Schwarzschild metric are interpreted as an indication of the supersymmetric multiplet structure of a black hole. The degree of degeneracy of a black hole is 2/sup 4n/ in SO(n) supergravity
Gravitino problem in minimal supergravity inflation
Directory of Open Access Journals (Sweden)
Fuminori Hasegawa
2017-04-01
Full Text Available We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory after inflation or a serious gravitino problem.
Gravitino problem in minimal supergravity inflation
Energy Technology Data Exchange (ETDEWEB)
Hasegawa, Fuminori [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Mukaida, Kyohei [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Nakayama, Kazunori [Department of Physics, Faculty of Science, The University of Tokyo, Bunkyo-ku, Tokyo 133-0033 (Japan); Terada, Takahiro, E-mail: terada@kias.re.kr [School of Physics, Korea Institute for Advanced Study (KIAS), Seoul 02455 (Korea, Republic of); Yamada, Yusuke [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94305 (United States)
2017-04-10
We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory after inflation or a serious gravitino problem.
Exploring extra dimensions through inflationary tensor modes
Im, Sang Hui; Nilles, Hans Peter; Trautner, Andreas
2018-03-01
Predictions of inflationary schemes can be influenced by the presence of extra dimensions. This could be of particular relevance for the spectrum of gravitational waves in models where the extra dimensions provide a brane-world solution to the hierarchy problem. Apart from models of large as well as exponentially warped extra dimensions, we analyze the size of tensor modes in the Linear Dilaton scheme recently revived in the discussion of the "clockwork mechanism". The results are model dependent, significantly enhanced tensor modes on one side and a suppression on the other. In some cases we are led to a scheme of "remote inflation", where the expansion is driven by energies at a hidden brane. In all cases where tensor modes are enhanced, the requirement of perturbativity of gravity leads to a stringent upper limit on the allowed Hubble rate during inflation.
Supergravity field theories and the art of constructing them
International Nuclear Information System (INIS)
Freedman, D.Z.
1977-01-01
The review of supergravity field theories includes global supersymmetry, supergravity, extended supergravity, minimal gauge coupling for spin-3/2 fields, and the general strategy of supergravity constructions. 39 references
International Nuclear Information System (INIS)
Adamietz, P.; Binetruy, P.; Girardi, G.; Grimm, R.
1992-07-01
The properties of a linear multiplet in interaction with supergravity and matter are presented, with a special emphasis on the coupling of Chern-Simons forms, relevant for the problem of the chiral and conformal anomalies in relation with Kaehler transformations and the corresponding anomaly cancellations. The linear supermultiplet describes an antisymmetric tensor gauge field together with a dilaton and a Majorana spinor. In particular, these fields are found among the massless modes of superstring theories. The general properties of this supermultiplet is reviewed in the Kaehler superspace formalism and the complete supersymmetric action is constructed. This includes the classically Kaehler invariant component field action for all the kinetic terms as well as a Green-Schwarz type action which exhibits a non-holomorphic gauge coupling function. (author) 32 refs
A scenario for inflationary magnetogenesis without strong coupling problem
Energy Technology Data Exchange (ETDEWEB)
Tasinato, Gianmassimo [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom); Institute of Cosmology and Gravitation, University of Portsmouth,Portsmouth, PO1 3FX (United Kingdom)
2015-03-23
Cosmological magnetic fields pervade the entire universe, from small to large scales. Since they apparently extend into the intergalactic medium, it is tantalizing to believe that they have a primordial origin, possibly being produced during inflation. However, finding consistent scenarios for inflationary magnetogenesis is a challenging theoretical problem. The requirements to avoid an excessive production of electromagnetic energy, and to avoid entering a strong coupling regime characterized by large values for the electromagnetic coupling constant, typically allow one to generate only a tiny amplitude of magnetic field during inflation. We propose a scenario for building gauge-invariant models of inflationary magnetogenesis potentially free from these issues. The idea is to derivatively couple a dynamical scalar, not necessarily the inflaton, to fermionic and electromagnetic fields during the inflationary era. Such couplings give additional freedom to control the time-dependence of the electromagnetic coupling constant during inflation. This fact allows us to find conditions to avoid the strong coupling problems that affect many of the existing models of magnetogenesis. We do not need to rely on a particular inflationary set-up for developing our scenario, that might be applied to different realizations of inflation. On the other hand, specific requirements have to be imposed on the dynamics of the scalar derivatively coupled to fermions and electromagnetism, that we are able to satisfy in an explicit realization of our proposal.
A scenario for inflationary magnetogenesis without strong coupling problem
Energy Technology Data Exchange (ETDEWEB)
Tasinato, Gianmassimo, E-mail: gianmassimo.tasinato@port.ac.uk [Department of Physics, Swansea University, Swansea, SA2 8PP U.K. (United Kingdom)
2015-03-01
Cosmological magnetic fields pervade the entire universe, from small to large scales. Since they apparently extend into the intergalactic medium, it is tantalizing to believe that they have a primordial origin, possibly being produced during inflation. However, finding consistent scenarios for inflationary magnetogenesis is a challenging theoretical problem. The requirements to avoid an excessive production of electromagnetic energy, and to avoid entering a strong coupling regime characterized by large values for the electromagnetic coupling constant, typically allow one to generate only a tiny amplitude of magnetic field during inflation. We propose a scenario for building gauge-invariant models of inflationary magnetogenesis potentially free from these issues. The idea is to derivatively couple a dynamical scalar, not necessarily the inflaton, to fermionic and electromagnetic fields during the inflationary era. Such couplings give additional freedom to control the time-dependence of the electromagnetic coupling constant during inflation. This fact allows us to find conditions to avoid the strong coupling problems that affect many of the existing models of magnetogenesis. We do not need to rely on a particular inflationary set-up for developing our scenario, that might be applied to different realizations of inflation. On the other hand, specific requirements have to be imposed on the dynamics of the scalar derivatively coupled to fermions and electromagnetism, that we are able to satisfy in an explicit realization of our proposal.
Stochastic dark energy from inflationary quantum fluctuations
Glavan, Dražen; Prokopec, Tomislav; Starobinsky, Alexei A.
2018-05-01
We study the quantum backreaction from inflationary fluctuations of a very light, non-minimally coupled spectator scalar and show that it is a viable candidate for dark energy. The problem is solved by suitably adapting the formalism of stochastic inflation. This allows us to self-consistently account for the backreaction on the background expansion rate of the Universe where its effects are large. This framework is equivalent to that of semiclassical gravity in which matter vacuum fluctuations are included at the one loop level, but purely quantum gravitational fluctuations are neglected. Our results show that dark energy in our model can be characterized by a distinct effective equation of state parameter (as a function of redshift) which allows for testing of the model at the level of the background.
The integral form of supergravity
Energy Technology Data Exchange (ETDEWEB)
Castellani, L. [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); Catenacci, R. [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale,Viale T. Michel, 11, 15121 Alessandria (Italy); Gruppo Nazionale di Fisica Matematica, INdAM,P.le Aldo Moro 5, 00185 Roma (Italy); 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)
2016-10-11
By using integral forms we derive the superspace action of D=3,N=1 supergravity as an integral on a supermanifold. The construction is based on target space picture changing operators, here playing the rôle of Poincaré duals to the lower-dimensional spacetime surfaces embedded into the supermanifold. We show how the group geometrical action based on the group manifold approach interpolates between the superspace and the component supergravity actions, thus providing another proof of their equivalence.
A higher-dimensional Bianchi type-I inflationary Universe in general ...
Indian Academy of Sciences (India)
Inflation, the stage of accelerated expansion of the Universe, first proposed ... ary model in the context of grand unified theory (GUT), which has been ... The role of self-interacting scalar fields in inflationary cosmology in four-dimensional.
Energy Technology Data Exchange (ETDEWEB)
Araujo, T.; O Colgain, E. [Asia Pacific Center for Theoretical Physics, Pohang (Korea, Republic of); Sakamoto, J.; Yoshida, K. [Kyoto University, Department of Physics, Kyoto (Japan); Sheikh-Jabbari, M.M. [Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of)
2017-11-15
We showed in previous work that for homogeneous Yang-Baxter (YB) deformations of AdS{sub 5} x S{sup 5} the open string metric and coupling and as a result the closed string density e{sup -2Φ}√(g) remain undeformed. In this work, in addition to extending these results to the deformation associated with the modified CYBE or η-deformation, we identify the Page forms as the open string counterpart for RR fields and demonstrate case by case that the non-zero Page forms remain invariant under YB deformations. We give a physical meaning to the Killing vector I of generalized supergravity and show for all YB deformations: (1) I appears as a current for the center of mass motion on the worldvolume of a D-brane probing the background, (2) I is equal to the divergence of the noncommutativity parameter, (3) I exhibits ''holographic'' behavior where the radial component of I vanishes at the AdS boundary and (4) in pure spinor formalism I is related to a certain state in the BRST cohomology. (orig.)
Scale invariant Volkov–Akulov supergravity
Directory of Open Access Journals (Sweden)
S. Ferrara
2015-10-01
Full Text Available A scale invariant goldstino theory coupled to supergravity is obtained as a standard supergravity dual of a rigidly scale-invariant higher-curvature supergravity with a nilpotent chiral scalar curvature. The bosonic part of this theory describes a massless scalaron and a massive axion in a de Sitter Universe.
Scale invariant Volkov–Akulov supergravity
Energy Technology Data Exchange (ETDEWEB)
Ferrara, S., E-mail: sergio.ferrara@cern.ch [Th-Ph Department, CERN, CH-1211 Geneva 23 (Switzerland); INFN – Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044 Frascati (Italy); Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Porrati, M., E-mail: mp9@nyu.edu [Th-Ph Department, CERN, CH-1211 Geneva 23 (Switzerland); CCPP, Department of Physics, NYU, 4 Washington Pl., New York, NY 10003 (United States); Sagnotti, A., E-mail: sagnotti@sns.it [Th-Ph Department, CERN, CH-1211 Geneva 23 (Switzerland); Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, 56126 Pisa (Italy)
2015-10-07
A scale invariant goldstino theory coupled to supergravity is obtained as a standard supergravity dual of a rigidly scale-invariant higher-curvature supergravity with a nilpotent chiral scalar curvature. The bosonic part of this theory describes a massless scalaron and a massive axion in a de Sitter Universe.
Starobinsky-type Inflation in Dynamical Supergravity Breaking Scenarios
Alexandre, Jean; Mavromatos, Nick E.
2014-01-27
In the context of dynamical breaking of local supersymmetry (supergravity), including the Deser-Zumino super-Higgs effect, for the simple but quite representative cases of N=1, D=4 supergravity, we discuss the emergence of Starobinsky-type inflation, due to quantum corrections in the effective action arising from integrating out gravitino fields in their massive phase. This type of inflation may occur after a first-stage small-field inflation that characterises models near the origin of the one-loop effective potential, and it may occur at the non-trivial minima of the latter. Phenomenologically realistic scenarios, compatible with the Planck data, may be expected for the conformal supergravity variants of the basic model.
Absence of U(1) anomalous superamplitudes in N≥5 supergravities
Energy Technology Data Exchange (ETDEWEB)
Freedman, Daniel Z. [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University,Stanford, CA 94305 (United States); Center for Theoretical Physics and Department of Mathematics,Massachusetts Institute of Technology,Cambridge, MA 02139 (United States); Kallosh, Renata; Murli, Divyanshu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University,Stanford, CA 94305 (United States); Proeyen, Antoine Van [KU Leuven, Institute for Theoretical Physics,Celestijnenlaan 200D, B-3001, Leuven (Belgium); Yamada, Yusuke [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University,Stanford, CA 94305 (United States)
2017-05-12
We list all potential candidates for U(1) anomalous non-local 1-loop 4-point amplitudes and higher loop UV divergences in N≥5 supergravities. The relevant chiral superinvariants are constructed from linearized chiral superfields and define the corresponding superamplitudes. The anomalous amplitudes, of the kind present in N=4, are shown to be absent in N≥5. In N=6 supergravity the result is deduced from the double-copy (N=4){sub YM}×(N=2){sub YM} model, whereas in N=5,8 the result on absence of anomalous amplitudes is derived in supergravities as well as in the (N=4){sub YM}×(N−4){sub YM} double-copy models.
Symmetries of supergravity black holes
International Nuclear Information System (INIS)
Chow, David D K
2010-01-01
We investigate Killing tensors for various black hole solutions of supergravity theories. Rotating black holes of an ungauged theory, toroidally compactified heterotic supergravity, with NUT parameters and two U(1) gauge fields are constructed. If both charges are set equal, then the solutions simplify, and then there are concise expressions for rank-2 conformal Killing-Staeckel tensors. These are induced by rank-2 Killing-Staeckel tensors of a conformally related metric that possesses a separability structure. We directly verify the separation of the Hamilton-Jacobi equation on this conformally related metric and of the null Hamilton-Jacobi and massless Klein-Gordon equations on the 'physical' metric. Similar results are found for more general solutions; we mainly focus on those with certain charge combinations equal in gauged supergravity but also consider some other solutions.
Studies in gravity and supergravity
International Nuclear Information System (INIS)
Castellani, L.
1981-01-01
The canonical treatment for theories with local gauge invariances is reviewed and an algorithm for the construction of all the gauge generators is found. This algorithm is then applied to Yang-Mills theories and to (metric) gravity. The first part of the work is concluded with a complete treatment of hamiltonian first order tetrad gravity. In the second part, the geometrical aspects of (super)gravity theories are concentrated on. After an interlude with path integrals in curved space (equivalence is shown with canonical quantization), N = 2 supergravity in superspace, and conformal supergravity in the group manifold scenario are studied. A progress report is added, regarding a study on higher divergences in quantum field theory
International Nuclear Information System (INIS)
Pernici, M.; Pilch, K.; Van Nieuwenhuizen, P.
1985-01-01
The complete gauged nonlinear N=8 d=5 supergravity action and supersymmetry transformation laws (without four- and three-fermion terms) are presented. They are obtained from the ungauged model by reinterpreting part of the field strengths of the abelian vector fields as real self-dual second-rank antisymmetric tensors. The complete set of T-tensor indentities are given and their validity is checked numerically. The model has a local Yang-Mills SO(6) and a local composite USp(8) symmetry. The self-duality is essential for the consistent coupling of the antisymmetric tensors to the nonabelian gauge fields. (orig.)
Cosmological imprints of pre-inflationary particles
Energy Technology Data Exchange (ETDEWEB)
Fialkov, Anastasia; Itzhaki, Nissan; Kovetz, Ely D., E-mail: anastasia.fialkov@gmail.com, E-mail: nitzhaki@post.tau.ac.il, E-mail: elykovetz@gmail.com [Tel-Aviv University, Ramat-Aviv, 69978 (Israel)
2010-02-01
We study some of the cosmological imprints of pre-inflationary particles. We show that each such particle provides a seed for a spherically symmetric cosmic defect. The profile of this cosmic defect is fixed and its magnitude is linear in a single parameter that is determined by the mass of the pre-inflationary particle. We study the CMB and peculiar velocity imprints of this cosmic defect and suggest that it could explain some of the large scale cosmological anomalies.
Cosmological imprints of pre-inflationary particles
International Nuclear Information System (INIS)
Fialkov, Anastasia; Itzhaki, Nissan; Kovetz, Ely D.
2010-01-01
We study some of the cosmological imprints of pre-inflationary particles. We show that each such particle provides a seed for a spherically symmetric cosmic defect. The profile of this cosmic defect is fixed and its magnitude is linear in a single parameter that is determined by the mass of the pre-inflationary particle. We study the CMB and peculiar velocity imprints of this cosmic defect and suggest that it could explain some of the large scale cosmological anomalies
New constraints on oscillations in the primordial spectrum of inflationary perturbations
Energy Technology Data Exchange (ETDEWEB)
Hamann, J.; Covi, L. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Melchiorri, A. [Univ. di Roma La Sapienza (Italy). Dipt. di Fisica and Sezione INFN; Slosar, A. [Oxford Univ. (United Kingdom). Dept. of Astrophysics]|[Ljubljana Univ. (Slovenia). Faculty of Mathematics and Physics
2007-01-15
We revisit the problem of constraining steps in the inflationary potential with cosmological data. We argue that a step in the inflationary potential produces qualitatively similar oscillations in the primordial power spectrum, independently of the details of the inflationary model. We propose a phenomenological description of these oscillations and constrain these features using a selection of cosmological data including the baryonic peak data from the correlation function of luminous red galaxies in the Sloan Digital Sky Survey. Our results show that degeneracies of the oscillation with standard cosmological parameters are virtually non-existent. The inclusion of new data severely tightens the constraints on the parameter space of oscillation parameters with respect to older work. This confirms that extensions to the simplest inflationary models can be successfully constrained using cosmological data. (orig.)
New constraints on oscillations in the primordial spectrum of inflationary perturbations
International Nuclear Information System (INIS)
Hamann, J.; Covi, L.; Melchiorri, A.; Slosar, A.; Ljubljana Univ.
2007-01-01
We revisit the problem of constraining steps in the inflationary potential with cosmological data. We argue that a step in the inflationary potential produces qualitatively similar oscillations in the primordial power spectrum, independently of the details of the inflationary model. We propose a phenomenological description of these oscillations and constrain these features using a selection of cosmological data including the baryonic peak data from the correlation function of luminous red galaxies in the Sloan Digital Sky Survey. Our results show that degeneracies of the oscillation with standard cosmological parameters are virtually non-existent. The inclusion of new data severely tightens the constraints on the parameter space of oscillation parameters with respect to older work. This confirms that extensions to the simplest inflationary models can be successfully constrained using cosmological data. (orig.)
A worldsheet theory for supergravity
Energy Technology Data Exchange (ETDEWEB)
Adamo, Tim; Casali, Eduardo; Skinner, David [Department of Applied Mathematics & Theoretical Physics, University of Cambridge,Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2015-02-18
We present a worldsheet theory that describes maps into a curved target space equipped with a B-field and dilaton. The conditions for the theory to be consistent at the quantum level can be computed exactly, and are that the target space fields obey the nonlinear d=10 supergravity equations of motion, with no higher curvature terms. The path integral is constrained to obey a generalization of the scattering equations to curved space. Remarkably, the supergravity field equations emerge as quantum corrections to these curved space scattering equations.
Inflationary α -attractor cosmology: A global dynamical systems perspective
Alho, Artur; Uggla, Claes
2017-04-01
We study flat Friedmann-Lemaître-Robertson-Walker α -attractor E- and T-models by introducing a dynamical systems framework that yields regularized unconstrained field equations on two-dimensional compact state spaces. This results in both illustrative figures and a complete description of the entire solution spaces of these models, including asymptotics. In particular, it is shown that observational viability, which requires a sufficient number of e -folds, is associated with a particular solution given by a one-dimensional center manifold of a past asymptotic de Sitter state, where the center manifold structure also explains why nearby solutions are attracted to this "inflationary attractor solution." A center manifold expansion yields a description of the inflationary regime with arbitrary analytic accuracy, where the slow-roll approximation asymptotically describes the tangency condition of the center manifold at the asymptotic de Sitter state.
Supersymmetric AdS6 solutions of type IIB supergravity
International Nuclear Information System (INIS)
Kim, Hyojoong; Kim, Nakwoo; Suh, Minwoo
2015-01-01
We study the general requirement for supersymmetric AdS 6 solutions in type IIB supergravity. We employ the Killing spinor technique and study the differential and algebraic relations among various Killing spinor bilinears to find the canonical form of the solutions. Our result agrees precisely with the work of Apruzzi et al. (JHEP 1411:099, 2014), which used the pure spinor technique. Hoping to identify the geometry of the problem, we also computed four-dimensional theory through the dimensional reduction of type IIB supergravity on AdS 6 . This effective action is essentially a non-linear sigma model with five scalar fields parametrizing SL(3,ℝ)/SO(2,1), modified by a scalar potential and coupled to Einstein gravity in Euclidean signature. We argue that the scalar potential can be explained by a subgroup CSO(1,1,1) ⊂SL(3,ℝ) in a way analogous to gauged supergravity
Inflaton decay in supergravity and gravitino problem
International Nuclear Information System (INIS)
Takahashi, F.
2007-09-01
We have recently shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. Taking account of these processes, we derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. (orig.)
The axion mass in modular invariant supergravity
International Nuclear Information System (INIS)
Butter, Daniel; Gaillard, Mary K.
2005-01-01
When supersymmetry is broken by condensates with a single condensing gauge group, there is a nonanomalous R-symmetry that prevents the universal axion from acquiring a mass. It has been argued that, in the context of supergravity, higher dimension operators will break this symmetry and may generate an axion mass too large to allow the identification of the universal axion with the QCD axion. We show that such contributions to the axion mass are highly suppressed in a class of models where the effective Lagrangian for gaugino and matter condensation respects modular invariance (T-duality)
General dimensional reduction of ten-dimensional supergravity and superstring
International Nuclear Information System (INIS)
Ferrara, S.; Porrati, M.
1986-01-01
Dimensional reductions of supergravity theories are shown to yield to specific glasses of four-dimensional no-scale models with N=4, 2 or 1 residual supersymmetry. N=1 ''maximal'' supergravity lagrangian, corresponding to the ''untwisted'' sector of orbifold compactification of superstrings, contains nine families and has a no-scale structure based on the Kaehler manifold [SU(3, 3+3n)/SU(3)xSU(3+3n)]x[SU(1, 1)/U(1)]. The quantum consistency of the resulting theories give information on the non Kaluza-Klein (string) ''twisted'' sector. (orig.)
Representations of algebras of extended supersymmetry and linearised supergravity theories
International Nuclear Information System (INIS)
Tejlor, Dzh.
1985-01-01
In the lecture an attempt is made to acquaint the reader with the theory of extended supersymmetry, to characterize the corresponding particle spectrum and to explain how it can be used in supersymmetry with the least difficulties. Superalgebras are classified, their irreducible representations are given. Superfields and superspace are introduced, their role in the superalgebra realization is analyzed. Examples of linearized Lagrangians and auxiliary fields for the theories of supergravity with N=1 and N=2 are presented. Methods of spin reduction with the central charges are considered. The possibility to construct supergravity model with N>=3 off mass shell is considered
Introduction to supersymmetry and supergravity
International Nuclear Information System (INIS)
West, P.
1990-01-01
This book discusses two-dimensional supersymmetry algebras, and their irreducible representations as well as rigid and local (supergravity) theories of supersymmetry both in x-space and superspace. These theories include the actions for the superstring and the heterotic string. A discussion on superconformal algebras in two dimensions and an account of super operator product expansion are included
Problems in unification and supergravity
Energy Technology Data Exchange (ETDEWEB)
Farrar, G.; Henyey, F. (eds.)
1984-01-01
Problems in unification of the various gauge groups, quantum gravity, supersymmetry and supergravity, compact dimensions of space-time, and conditions at the beginning of the universe are discussed. Separate entries were prepared for the data base for the 15 papers presented. (WHK)
Problems in unification and supergravity
International Nuclear Information System (INIS)
Farrar, G.; Henyey, F.
1984-01-01
Problems in unification of the various gauge groups, quantum gravity, supersymmetry and supergravity, compact dimensions of space-time, and conditions at the beginning of the universe are discussed. Separate entries were prepared for the data base for the 15 papers presented
Geometric construction of extended supergravity
International Nuclear Information System (INIS)
Kostelecky, V.A.
1982-01-01
This work describes the explict construction of the locally SO(4)-invariant, on-shell de Sitter supergravity. First, aspects of classical differential geometry used in the construction of local gauge theories are reviewed. Emphasis is placed on fiber bundles and their uses in Yang-Mills and Einstein theories. Next, the extension of the formalism to differential supergeometry is outlined. Applications to extended supergravities are discussed. Finally, the O(4) deSitter supergravity is obtained by considering a bundle of frames constructed using the orthosymplectic superalgebra osp(4/4). The structure group of this bundle is Sl(2C) x SO(4) and the tangent space to the base supermanifold is homeomorphic to the coset osp(4/4)/sl(2C) x so(4). Constraints taken into the Bianchi identifies yield a realization of the superalgebra in the function space of connections, vielbeins, curvatures and torsions of the bundle. Auxiliary fields, transformation laws and equations of motion are determined. Consistency of the realization is verified, proving closure of the algebra. The associated Poincare supergravity is obtained by a contraction
Cartan's geometrical structure of supergravity
International Nuclear Information System (INIS)
Baaklini, N.S.
1977-06-01
The geometrical partnership of the vierbein and the spin-3/2 field in the structure of the supergravity Lagrangian is emphasized. Both fields are introduced as component of the same matrix differential form. The only local symmetry of the theory is SL(2,C)
Nonlinear self-duality and supergravity
International Nuclear Information System (INIS)
Kuzenko, Sergei M.; McCarthy, Shane A.
2003-01-01
The concept of self-dual supersymmetric nonlinear electrodynamics is generalized to a curved superspace of N=1 supergravity, for both the old minimal and the new minimal versions of N=1 supergravity. We derive the self-duality equation, which has to be satisfied by the action functional of any U(1) duality invariant model of a massless vector multiplet, and construct a family of self-dual nonlinear models. This family includes a curved superspace extension of the N=1 super Born-Infeld action. The supercurrent and supertrace in such models are proved to be duality invariant. The most interesting and unexpected result is that the requirement of nonlinear self-duality yields nontrivial couplings of the vector multiplet to Kaehler sigma models. We explicitly derive the couplings to general Kaehler sigma models in the case when the matter chiral multiplets are inert under the duality rotations, and more specifically to the dilaton-axion chiral multiplet when the group of duality rotations is enhanced to SL(2,R). (author)
Spontaneous breaking of supersymmetry and gauge invariance in supergravity
Energy Technology Data Exchange (ETDEWEB)
Sohnius, M. (European Organization for Nuclear Research, Geneva (Switzerland)); West, P. (King' s Coll., London (UK). Dept. of Mathematics)
1982-08-09
Using the new minimal auxillary fields of N = 1 supergravity it is found possible to construct a model of local supersymmetry which spontaneously breaks both supersymmetry and gauge invariance. The status of the cosmological constant resulting from this breaking is discussed.
Spontaneous breaking of supersymmetry and gauge invariance in supergravity
International Nuclear Information System (INIS)
Sohnius, M.; West, P.
1982-01-01
Using the new minimal auxillary fields of N = 1 supergravity it is found possible to construct a model of local supersymmetry which spontaneously breaks both supersymmetry and gauge invariance. The status of the cosmological constant resulting from this breaking is discussed. (orig.)
On what scale should inflationary observables be constrained?
International Nuclear Information System (INIS)
Cortes, Marina; Liddle, Andrew R.; Mukherjee, Pia
2007-01-01
We examine the choice of scale at which constraints on inflationary observables are presented. We describe an implementation of the hierarchy of inflationary consistency equations which ensures that they remain enforced on different scales, and then seek to optimize the scale for presentation of constraints on marginalized inflationary parameters from WMAP3 data. For models with spectral index running, we find a strong variation of the constraints through the range of observational scales available, and optimize by finding the scale which decorrelates constraints on the spectral index n S and the running. This scale is k=0.017 Mpc -1 , and gives a reduction by a factor of more than four in the allowed parameter area in the n S -r plane (r being the tensor-to-scalar ratio) relative to k=0.002 Mpc -1 . These optimized constraints are similar to those obtained in the no-running case. We also extend the analysis to a larger compilation of data, finding essentially the same conclusions
Inflationary scenario from higher curvature warped spacetime
International Nuclear Information System (INIS)
Banerjee, Narayan; Paul, Tanmoy
2017-01-01
We consider a five dimensional warped spacetime, in presence of the higher curvature term like F(R) = R + αR 2 in the bulk, in the context of the two-brane model. Our universe is identified with the TeV scale brane and emerges as a four dimensional effective theory. From the perspective of this effective theory, we examine the possibility of ''inflationary scenario'' by considering the on-brane metric ansatz as an FRW one. Our results reveal that the higher curvature term in the five dimensional bulk spacetime generates a potential term for the radion field. Due to the presence of radion potential, the very early universe undergoes a stage of accelerated expansion and, moreover, the accelerating period of the universe terminates in a finite time. We also find the spectral index of curvature perturbation (n s ) and the tensor to scalar ratio (r) in the present context, which match with the observational results based on the observations of Planck (Astron. Astrophys. 594, A20, 2016). (orig.)
Inflationary scenario from higher curvature warped spacetime
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Narayan [Indian Institute of Science Education and Research Kolkata, Department of Physical Sciences, Nadia, West Bengal (India); Paul, Tanmoy [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)
2017-10-15
We consider a five dimensional warped spacetime, in presence of the higher curvature term like F(R) = R + αR{sup 2} in the bulk, in the context of the two-brane model. Our universe is identified with the TeV scale brane and emerges as a four dimensional effective theory. From the perspective of this effective theory, we examine the possibility of ''inflationary scenario'' by considering the on-brane metric ansatz as an FRW one. Our results reveal that the higher curvature term in the five dimensional bulk spacetime generates a potential term for the radion field. Due to the presence of radion potential, the very early universe undergoes a stage of accelerated expansion and, moreover, the accelerating period of the universe terminates in a finite time. We also find the spectral index of curvature perturbation (n{sub s}) and the tensor to scalar ratio (r) in the present context, which match with the observational results based on the observations of Planck (Astron. Astrophys. 594, A20, 2016). (orig.)
Galilean creation of the inflationary universe
Energy Technology Data Exchange (ETDEWEB)
Kobayashi, Tsutomu [Department of Physics, Rikkyo University, Toshima, Tokyo 175-8501 (Japan); Yamaguchi, Masahide [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Yokoyama, Jun' ichi, E-mail: tsutomu@rikkyo.ac.jp, E-mail: gucci@phys.titech.ac.jp, E-mail: yokoyama@resceu.s.u-tokyo.ac.jp [Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)
2015-07-01
It has been pointed out that the null energy condition can be violated stably in some non-canonical scalar-field theories. This allows us to consider the Galilean Genesis scenario in which the universe starts expanding from Minkowski spacetime and hence is free from the initial singularity. We use this scenario to study the early-time completion of inflation, pushing forward the recent idea of Pirtskhalava et al. We present a generic form of the Lagrangian governing the background and perturbation dynamics in the Genesis phase, the subsequent inflationary phase, and the graceful exit from inflation, as opposed to employing the effective field theory approach. Our Lagrangian belongs to a more general class of scalar-tensor theories than the Horndeski theory and Gleyzes-Langlois-Piazza-Vernizzi generalization, but still has the same number of the propagating degrees of freedom, and thus can avoid Ostrogradski instabilities. We investigate the generation and evolution of primordial perturbations in this scenario and show that one can indeed construct a stable model of inflation preceded by (generalized) Galilean Genesis.
Galilean creation of the inflationary universe
Energy Technology Data Exchange (ETDEWEB)
Kobayashi, Tsutomu [Department of Physics, Rikkyo University,Toshima, Tokyo 175-8501 (Japan); Yamaguchi, Masahide [Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan); Yokoyama, Jun’ichi [Research Center for the Early Universe (RESCEU),Graduate School of Science, The University of Tokyo,Tokyo 113-0033 (Japan); Department of Physics, Graduate School of Science, The University of Tokyo,Tokyo 113-0033 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU),UTIAS, WPI, The University of Tokyo,Kashiwa, Chiba 277-8568 (Japan)
2015-07-13
It has been pointed out that the null energy condition can be violated stably in some non-canonical scalar-field theories. This allows us to consider the Galilean Genesis scenario in which the universe starts expanding from Minkowski spacetime and hence is free from the initial singularity. We use this scenario to study the early-time completion of inflation, pushing forward the recent idea of Pirtskhalava et al. We present a generic form of the Lagrangian governing the background and perturbation dynamics in the Genesis phase, the subsequent inflationary phase, and the graceful exit from inflation, as opposed to employing the effective field theory approach. Our Lagrangian belongs to a more general class of scalar-tensor theories than the Horndeski theory and Gleyzes-Langlois-Piazza-Vernizzi generalization, but still has the same number of the propagating degrees of freedom, and thus can avoid Ostrogradski instabilities. We investigate the generation and evolution of primordial perturbations in this scenario and show that one can indeed construct a stable model of inflation preceded by (generalized) Galilean Genesis.
Helical Phase Inflation and Monodromy in Supergravity Theory
Directory of Open Access Journals (Sweden)
Tianjun Li
2015-01-01
Full Text Available We study helical phase inflation which realizes “monodromy inflation” in supergravity theory. In the model, inflation is driven by the phase component of a complex field whose potential possesses helicoid structure. We construct phase monodromy based on explicitly breaking global U(1 symmetry in the superpotential. By integrating out heavy fields, the phase monodromy from single complex scalar field is realized and the model fulfills natural inflation. The phase-axion alignment is achieved from explicitly symmetry breaking and gives super-Planckian phase decay constant. The F-term scalar potential provides strong field stabilization for all the scalars except inflaton, which is protected by the approximate global U(1 symmetry. Besides, we show that helical phase inflation can be naturally realized in no-scale supergravity with SU(2,1/SU(2×U(1 symmetry since the supergravity setup needed for phase monodromy is automatically provided in the no-scale Kähler potential. We also demonstrate that helical phase inflation can be reduced to another well-known supergravity inflation model with shift symmetry. Helical phase inflation is free from the UV-sensitivity problem although there is super-Planckian field excursion, and it suggests that inflation can be effectively studied based on supersymmetric field theory while a UV-completed framework is not prerequisite.
On maximal massive 3D supergravity
Bergshoeff , Eric A; Hohm , Olaf; Rosseel , Jan; Townsend , Paul K
2010-01-01
ABSTRACT We construct, at the linearized level, the three-dimensional (3D) N = 4 supersymmetric " general massive supergravity " and the maximally supersymmetric N = 8 " new massive supergravity ". We also construct the maximally supersymmetric linearized N = 7 topologically massive supergravity, although we expect N = 6 to be maximal at the non-linear level. (Bergshoeff, Eric A) (Hohm, Olaf) (Rosseel, Jan) P.K.Townsend@da...
Spontaneous symmetry breaking in N=3 supergravity
International Nuclear Information System (INIS)
Zinov'ev, Yu.M.
1986-01-01
The possibility of the spontaneous symmetry breaking without a cosmological term in N=3 supergravity is investigated. A new, dual version of N=3 supergravity - U(3)-supergravity is constructed. Such a theory is shown to admit a spontaneous supersymmetry breaking without a cosmological term and with three arbitrary scales, including partial super-Higgs effect N=3 → N=2 and N=3 → N=1
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.)
Minimal N=4 topologically massive supergravity
Energy Technology Data Exchange (ETDEWEB)
Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Novak, Joseph [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Golm (Germany); Sachs, Ivo [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität,Theresienstraße 37, D-80333 München (Germany)
2017-03-21
Using the superconformal framework, we construct a new off-shell model for N=4 topologically massive supergravity which is minimal in the sense that it makes use of a single compensating vector multiplet and involves no free parameter. As such, it provides a counterexample to the common lore that two compensating multiplets are required within the conformal approach to supergravity with eight supercharges in diverse dimensions. This theory is an off-shell N=4 supersymmetric extension of chiral gravity. All of its solutions correspond to non-conformally flat superspaces. Its maximally supersymmetric solutions include the so-called critical (4,0) anti-de Sitter superspace introduced in https://www.doi.org/10.1007/JHEP08(2012)024, and well as warped critical (4,0) anti-de Sitter superspaces. We also propose a dual formulation for the theory in which the vector multiplet is replaced with an off-shell hypermultiplet. Upon elimination of the auxiliary fields belonging to the hypermultiplet and imposing certain gauge conditions, the dual action reduces to the one introduced in https://www.doi.org/10.1103/PhysRevD.94.065028.
Calculations of Inflaton Decays and Reheating: with Applications to No-Scale Inflation Models
Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A
2015-01-01
We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\\rm reh}$, and the number of inflationary e-folds, $N_*$, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index $n_s$ and the tensor-to-scalar perturbation ratio $r$, converting them into constraints on $N_*$, the inflaton decay rate and other parameters of specific no-scale inflationary models.
On matter couplings in N=1 supergravities
International Nuclear Information System (INIS)
Galperin, A.; Ogievskiy, V.; Sokatchev, E.
1983-01-01
A flexible version of N=1 supergravity is proposed. It contains 28+28 fields and is an extension of the new minimal supergravity version. Matter couplings in various N=1 supergravity versions are discussed. The chiral densities are constructed for non-minimal and flexible versions. Therefore these versions admit a general R-non-invariant matter coupling as the minimal supergravity does. A modified Fayet-Iliopoulos type mechanism is conjectured which apparently can work in the non-minimal and flexible versions without R-symmetry of the superpotential unlike the minimal and new minimal ones
Unconstrained multiplet in N=2 conformal supergravity
International Nuclear Information System (INIS)
Hayashi, Masahito; Uehara, Shozo.
1985-02-01
An unconstrained (general) multiplet was studied in N = 2 conformal supergravity. Transformation law, embedding formula and multiplication rule are explicitly presented at the linearized level. (author)
Long range supergravity coupling strengths
International Nuclear Information System (INIS)
Kenyon, I.R.
1991-01-01
A limit of 2x10 -13 has recently been deduced for the fractional difference between the gravitational masses of the K 0 and anti K 0 mesons. This limit is applied here to put stringent limits on the strengths of the long range vector-scalar gravitational couplings envisaged in supergravity theories. A weaker limit is inferred from the general relativistic fit to the precession of the orbit of the pulsar PSR1913+16. (orig.)
Higgs mechanism and cosmological constant in N = 1 supergravity with inflaton in a vector multiplet
Energy Technology Data Exchange (ETDEWEB)
Aldabergenov, Yermek [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); Ketov, Sergei V. [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); The University of Tokyo, Kavli Institute for the Physics and Mathematics of the Universe (IPMU), Chiba (Japan); Tomsk Polytechnic University, Institute of Physics and Technology, Tomsk (Russian Federation)
2017-04-15
The N = 1 supergravity models of cosmological inflation with an inflaton belonging to a massive vector multiplet and spontaneous SUSY breaking after inflation are reformulated as the supersymmetric U(1) gauge theories of a massless vector superfield interacting with the Higgs and Polonyi chiral superfields, all coupled to supergravity. The U(1) gauge sector is identified with the U(1) gauge fields of the super-GUT coupled to supergravity, whose gauge group has a U(1) factor. A positive cosmological constant (dark energy) is included. The scalar potential is calculated, and its de Sitter vacuum solution is found to be stable. (orig.)
Linearized supergravity with a dynamical preferred frame
Marakulin, Arthur
2016-01-01
We study supersymmetric extension of the Einstein-aether gravitational model where local Lorentz invariance is broken down to the subgroup of spatial rotations by a vacuum expectation value of a timelike vector field. By restricting to the level of linear perturbations around Lorentz-violating vacuum and using the superfield formalism we construct the most general action invariant under the linearized supergravity transformations. We show that, unlike its non-supersymmetric counterpart, the model contains only a single free dimensionless parameter, besides the usual dimensionful gravitational coupling. This makes the model highly predictive. An analysis of the spectrum of physical excitations reveal superluminal velocity of gravitons. The latter property leads to the extension of the gravitational multiplet by additional fermonic and bosonic states with helicities $\\pm 3/2$ and $\\pm 1$. We outline the observational constraints on the model following from its low-energy phenomenology.
Quantum creation of an inflationary Universe
International Nuclear Information System (INIS)
Linde, A.D.
1984-01-01
The problem of quantum creation of the Universe is discussed. It is shown that the process of quantum creation of the Universe in a wide class on elementary particle theories leads with a high probability to the creation of an exponentially expanding (inflationary) Universe. Universe size after expansion should exceed l approximately 10 28 cm
Possibly Large Corrections to the Inflationary Observables
Bartolo, N
2008-01-01
We point out that the theoretical predictions for the inflationary observables may be generically altered by the presence of fields which are heavier than the Hubble rate during inflation and whose dynamics is usually neglected. They introduce corrections which may be easily larger than both the second-order contributions in the slow-roll parameters and the accuracy expected in the forthcoming experiments.
More gaugings of N=8 supergravity
International Nuclear Information System (INIS)
Hull, C.M.
1984-01-01
New non-compact gaugings of N = 8 supergravity are constructed. The gauge groups are SO(p,q) (with p + q = 8) and the group contraction of SO(p,q) about SO(p). The SO(4,4) gauging and the corresponding contraction truncate to gauged N = 4 supergravity theories. (orig.)
Experimental limits on antigravity in extended supergravity
Bellucci, S.; Faraoni, V.
1995-01-01
The available tests of the equivalence principle constrain the mass of the Higgs-like boson appearing in extended supergravity theories. We determine the constraints imposed by the present and future high precision experiments on the antigravity fields arising from $N=2,8$ supergravity.
Inflationary cosmology with Chaplygin gas in Palatini formalism
International Nuclear Information System (INIS)
Borowiec, Andrzej; Wojnar, Aneta; Stachowski, Aleksander; Szydłowski, Marek
2016-01-01
We present a simple generalisation of the ΛCDM model which on the one hand reaches very good agreement with the present day experimental data and provides an internal inflationary mechanism on the other hand. It is based on Palatini modified gravity with quadratic Starobinsky term and generalized Chaplygin gas as a matter source providing, besides a current accelerated expansion, the epoch of endogenous inflation driven by type III freeze singularity. It follows from our statistical analysis that astronomical data favors negative value of the parameter coupling quadratic term into Einstein-Hilbert Lagrangian and as a consequence the bounce instead of initial Big-Bang singularity is preferred
Inflationary fluctuations, entropy generation and baryogenesis in a cold universe
International Nuclear Information System (INIS)
Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.A.
1987-01-01
We study the implications of a generic inflationary model for scenarios of baryogenesis based on the decays of coherent oscillations of squark and slepton fields. We consider the effects of de Sitter fluctuations on the magnitudes of the coherent oscillations of squarks and sleptons. We see that the largest contribution to the entropy density is due to inflation decays which together with the value of the oscillation amplitude determined by the de Sitter fluctuations leads to a baryon to entropy ratio O(10 -10 ). The isothermal density fluctuations produced by the coherent oscillations are found to be negligible compared with the adiabatic fluctuations produced during inflation. (orig.)
Inflationary cosmology with Chaplygin gas in Palatini formalism
Energy Technology Data Exchange (ETDEWEB)
Borowiec, Andrzej; Wojnar, Aneta [Institute for Theoretical Physics, University of Wrocław, pl. M. Borna 9, 50-204, Wrocław (Poland); Stachowski, Aleksander; Szydłowski, Marek, E-mail: andrzej.borowiec@ift.uni.wroc.pl, E-mail: aleksander.stachowski@uj.edu.pl, E-mail: marek.szydlowski@uj.edu.pl, E-mail: aneta.wojnar@ift.uni.wroc.pl [Astronomical Observatory, Jagiellonian University, Orla 171, 30-244 Kraków (Poland)
2016-01-01
We present a simple generalisation of the ΛCDM model which on the one hand reaches very good agreement with the present day experimental data and provides an internal inflationary mechanism on the other hand. It is based on Palatini modified gravity with quadratic Starobinsky term and generalized Chaplygin gas as a matter source providing, besides a current accelerated expansion, the epoch of endogenous inflation driven by type III freeze singularity. It follows from our statistical analysis that astronomical data favors negative value of the parameter coupling quadratic term into Einstein-Hilbert Lagrangian and as a consequence the bounce instead of initial Big-Bang singularity is preferred.
The effective supergravity of little string theory
Antoniadis, Ignatios; Delgado, Antonio; Markou, Chrysoula; Pokorski, Stefan
2018-02-01
In this work we present the minimal supersymmetric extension of the five-dimensional dilaton-gravity theory that captures the main properties of the holographic dual of little string theory. It is described by a particular gauging of N=2 supergravity coupled with one vector multiplet associated with the string dilaton, along the U(1) subgroup of SU(2) R-symmetry. The linear dilaton in the fifth coordinate solution of the equations of motion (with flat string frame metric) breaks half of the supersymmetries to N=1 in four dimensions. Interest in the linear dilaton model has lately been revived in the context of the clockwork mechanism, which has recently been proposed as a new source of exponential scale separation in field theory.
The effective supergravity of little string theory
Energy Technology Data Exchange (ETDEWEB)
Antoniadis, Ignatios [Sorbonne Universite, CNRS, Laboratoire de Physique Theorique et Hautes Energies, LPTHE, Paris (France); University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland); Delgado, Antonio [University of Notre Dame, Department of Physics, Notre Dame, IN (United States); Markou, Chrysoula [Sorbonne Universite, CNRS, Laboratoire de Physique Theorique et Hautes Energies, LPTHE, Paris (France); Pokorski, Stefan [University of Warsaw, Faculty of Physics, Institute of Theoretical Physics, Warsaw (Poland)
2018-02-15
In this work we present the minimal supersymmetric extension of the five-dimensional dilaton-gravity theory that captures the main properties of the holographic dual of little string theory. It is described by a particular gauging of N = 2 supergravity coupled with one vector multiplet associated with the string dilaton, along the U(1) subgroup of SU(2) R-symmetry. The linear dilaton in the fifth coordinate solution of the equations of motion (with flat string frame metric) breaks half of the supersymmetries to N = 1 in four dimensions. Interest in the linear dilaton model has lately been revived in the context of the clockwork mechanism, which has recently been proposed as a new source of exponential scale separation in field theory. (orig.)
Minimal scalar-less matter-coupled supergravity
Energy Technology Data Exchange (ETDEWEB)
Dall' Agata, Gianguido, E-mail: dallagat@pd.infn.it [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay, F-91128 Palaiseau (France); Ferrara, Sergio [Theory Unit, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); INFN, Laboratori Nazionali di Frascati, Via Enrico Fermi 40, I-00044 Frascati (Italy); Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547 (United States); Zwirner, Fabio [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Theory Unit, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)
2016-01-10
We build the minimal supergravity model where the nilpotent chiral goldstino superfield is coupled to a chiral matter superfield, realising a different non-linear representation through a mixed nilpotency constraint. The model describes the spontaneous breaking of local supersymmetry in the presence of a generically massive Majorana fermion, but in the absence of elementary scalars. The sign and the size of the cosmological constant, the spectrum and the four-fermion interactions are controlled by suitable parameters.
Minimal scalar-less matter-coupled supergravity
Dall'Agata, Gianguido; Zwirner, Fabio
2016-01-01
We build the minimal supergravity model where the nilpotent chiral goldstino superfield is coupled to a chiral matter superfield, realising a different non-linear representation through a mixed nilpotency constraint. The model describes the spontaneous breaking of local supersymmetry in the presence of a generically massive Majorana fermion, but in the absence of elementary scalars. The sign and the size of the cosmological constant, the spectrum and the four-fermion interactions are controlled by suitable parameters.
Testing predictions of the quantum landscape multiverse 1: the Starobinsky inflationary potential
International Nuclear Information System (INIS)
Valentino, Eleonora Di; Mersini-Houghton, Laura
2017-01-01
The 2015 Planck data release has placed tight constraints on the allowed class of inflationary models. The current data favors concave downwards inflationary potentials while offering interesting hints on possible deviations from the standard picture of CMB perturbations. We here test the predictions of the theory of the origin of the universe from the landscape multiverse, against the most recent Planck data, for the case of concave downwards inflationary potentials, such as the Starobinsky model of inflation. By considering the quantum entanglement correction of the multiverse, we can place a lower limit on the local 'SUSY breaking' scale b > 1.2 × 10 7 GeV at 95% c.l. from Planck TT+lowTEB. We find that this limit is consistent with the range for b that allows the landscape multiverse to explain a serie of anomalies present in the current data.
Testing predictions of the quantum landscape multiverse 1: the Starobinsky inflationary potential
Energy Technology Data Exchange (ETDEWEB)
Valentino, Eleonora Di [Institut d' Astrophysique de Paris (UMR7095: CNRS and UPMC-Sorbonne Universities), F-75014, Paris (France); Mersini-Houghton, Laura, E-mail: valentin@iap.fr, E-mail: mersini@physics.unc.edu [Department of Physics and Astronomy, UNC-Chapel Hill, NC 27599 (United States)
2017-03-01
The 2015 Planck data release has placed tight constraints on the allowed class of inflationary models. The current data favors concave downwards inflationary potentials while offering interesting hints on possible deviations from the standard picture of CMB perturbations. We here test the predictions of the theory of the origin of the universe from the landscape multiverse, against the most recent Planck data, for the case of concave downwards inflationary potentials, such as the Starobinsky model of inflation. By considering the quantum entanglement correction of the multiverse, we can place a lower limit on the local 'SUSY breaking' scale b > 1.2 × 10{sup 7} GeV at 95% c.l. from Planck TT+lowTEB. We find that this limit is consistent with the range for b that allows the landscape multiverse to explain a serie of anomalies present in the current data.
Testing predictions of the quantum landscape multiverse 1: the Starobinsky inflationary potential
Di Valentino, Eleonora; Mersini-Houghton, Laura
2017-03-01
The 2015 Planck data release has placed tight constraints on the allowed class of inflationary models. The current data favors concave downwards inflationary potentials while offering interesting hints on possible deviations from the standard picture of CMB perturbations. We here test the predictions of the theory of the origin of the universe from the landscape multiverse, against the most recent Planck data, for the case of concave downwards inflationary potentials, such as the Starobinsky model of inflation. By considering the quantum entanglement correction of the multiverse, we can place a lower limit on the local `SUSY breaking' scale b > 1.2 × 107 GeV at 95% c.l. from Planck TT+lowTEB. We find that this limit is consistent with the range for b that allows the landscape multiverse to explain a serie of anomalies present in the current data.
Study of inflationary generalized cosmic Chaplygin gas for standard and tachyon scalar fields
Energy Technology Data Exchange (ETDEWEB)
Sharif, M.; Saleem, Rabia [University of the Punjab, Department of Mathematics, Lahore (Pakistan)
2014-07-15
We consider an inflationary universe model in the context of the generalized cosmic Chaplygin gas by taking the matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during the intermediate and logamediate inflationary regimes by modifying the first Friedmann equation. In each case, we evaluate the number of e-folds, scalar as well as tensor power spectra, scalar spectral index, and the important observational parameter, the tensor-scalar ratio in terms of inflation. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case. (orig.)
Study of inflationary generalized cosmic Chaplygin gas for standard and tachyon scalar fields
International Nuclear Information System (INIS)
Sharif, M.; Saleem, Rabia
2014-01-01
We consider an inflationary universe model in the context of the generalized cosmic Chaplygin gas by taking the matter field as standard and tachyon scalar fields. We evaluate the corresponding scalar fields and scalar potentials during the intermediate and logamediate inflationary regimes by modifying the first Friedmann equation. In each case, we evaluate the number of e-folds, scalar as well as tensor power spectra, scalar spectral index, and the important observational parameter, the tensor-scalar ratio in terms of inflation. The graphical behavior of this parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case. (orig.)
Post-Inflationary Gravitino Production Revisited
Ellis, John; Nanopoulos, Dimitri V.; Olive, Keith A.; Peloso, Marco
2016-01-01
We revisit gravitino production following inflation. As a first step, we review the standard calculation of gravitino production in the thermal plasma formed at the end of post-inflationary reheating when the inflaton has completely decayed. Next we consider gravitino production prior to the completion of reheating, assuming that the inflaton decay products thermalize instantaneously while they are still dilute. We then argue that instantaneous thermalization is in general a good approximation, and also show that the contribution of non-thermal gravitino production via the collisions of inflaton decay products prior to thermalization is relatively small. Our final estimate of the gravitino-to-entropy ratio is approximated well by a standard calculation of gravitino production in the post-inflationary thermal plasma assuming total instantaneous decay and thermalization at a time $t \\simeq 1.2/\\Gamma_\\phi$. Finally, in light of our calculations, we consider potential implications of upper limits on the gravitin...
On the initial condition of inflationary fluctuations
International Nuclear Information System (INIS)
Jiang, Hongliang; Wang, Yi; Zhou, Siyi
2016-01-01
It is usually assumed that the inflationary fluctuations start from the Bunch-Davies (BD) vacuum and the iε prescription is used when interactions are calculated. We show that those assumptions can be verified explicitly by calculating the loop corrections to the inflationary two-point and three-point correlation functions. Those loop corrections can be resummed to exponential factors, which suppress non-BD coefficients and behave as the iε factor for the case of the BD initial condition. A new technique of loop chain diagram resummation is developed for this purpose. For the non-BD initial conditions which is setup at finite time and has not fully decayed, explicit correction to the two-point and three-point correlation functions are calculated. Especially, non-Gaussianity in the folded limit is regularized due to the interactions.
Prospects for Inflationary B-Mode Detection
Kogut, Alan J.
2011-01-01
Measurements of the linear polarization of the cosmic microwave background provide a direct window into the physics of inflation. The experimental challenges are daunting: not only is the predicted signal faint compared to the photon noise limit, but it is hidden behind competing foregrounds from both local and cosmic sources. I will discuss the experimental response to these challenges and the prospects for eventual detection and characterization of the inflationary signal.
Generalizing minimal supergravity
International Nuclear Information System (INIS)
Li, Tianjun; Nanopoulos, Dimitri V.
2010-01-01
In Grand Unified Theories (GUTs), the Standard Model (SM) gauge couplings need not be unified at the GUT scale due to the high-dimensional operators. Considering gravity mediated supersymmetry breaking, we study for the first time the generic gauge coupling relations at the GUT scale, and the general gaugino mass relations which are valid from the GUT scale to the electroweak scale at one loop. We define the index k for these relations, which can be calculated in GUTs and can be determined at the Large Hadron Collider and the future International Linear Collider. Thus, we give a concrete definition of the GUT scale in these theories, and suggest a new way to test general GUTs at future experiments. We also discuss five special scenarios with interesting possibilities. With our generic formulae, we present all the GUT-scale gauge coupling relations and all the gaugino mass relations in the SU(5) and SO(10) models, and calculate the corresponding indices k. Especially, the index k is 5/3 in the traditional SU(5) and SO(10) models that have been studied extensively so far. Furthermore, we discuss the field theory realization of the U(1) flux effects on the SM gauge kinetic functions in F-theory GUTs, and calculate their indices k as well.
Supergravity, Dark Energy and the Fate of the Universe
Energy Technology Data Exchange (ETDEWEB)
Shmakova, Marina
2002-09-27
We propose a description of dark energy and acceleration of the universe in extended supergravities with de Sitter (dS) solutions. Some of them are related to M-theory with non-compact internal spaces. Masses of ultra-light scalars in these models are quantized in units of the Hubble constant: m{sup 2} = nH{sup 2}. If dS solution corresponds to a minimum of the effective potential, the universe eventually becomes dS space. If dS solution corresponds to a maximum or a saddle point, which is the case in all known models based on N = 8 supergravity, the flat universe eventually stops accelerating and collapses to a singularity. We show that in these models, as well as in the simplest models of dark energy based on N = 1 supergravity, the typical time remaining before the global collapse is comparable to the present age of the universe, t = O(10{sup 10}) years. We discuss the possibility of distinguishing between various models and finding our destiny using cosmological observations.
Some features of SUSY breaking in N=2 supergravity
International Nuclear Information System (INIS)
Cecotti, S.; Giradello, L.; Porrati, M.
1984-08-01
We discuss some features of SUSY breaking in N=2 Supergravity. Firstly, we show that in a general N=2 Sugra model (constructed according to the tensor calculus) all stationary points of the potential, at Λ=0, are fully supersymmetric if the compensating multiplet is not gauged. Thus a viable super-Higgs effect in N=2 supergravity can occur only in the presence of a Fayet-Iliopoulos term. Then we present an explicit model with two scales of breaking in anti-de Sitter space. Moreover, the ratio of the two gravitino masses is sliding i.e. not determined by the classical potential. In the extreme situation one of the gravitino mass equals √-Λ/3, and thus we have partial super-Higgs (in AdS space). The cosmological constant may be arranged to an arbitrary small value while keeping the mass of the heavy gravitino constant. (author)
Axion-dilaton domain walls and fake supergravity
International Nuclear Information System (INIS)
Sonner, Julian; Townsend, Paul K
2007-01-01
Dynamical systems methods are used to investigate domain-wall solutions of a two-parameter family of models in which gravity is coupled to an axion and to a dilaton with an exponential potential of either sign. A complete global analysis is presented for (i) constant axion and (ii) flat walls, including a study of bifurcations and a new exact domain-wall solution with non-constant axion. We reconsider 'fake-supergravity' issues in light of these results. We show, by example, how domain walls determine multi-valued superpotentials that branch at stationary points that are not stationary points of the potential, and we apply this result to potentials with anti-de Sitter vacua. We also show by example that 'adapted' truncation to a single-scalar model may be inconsistent, and we propose a 'generalized' fake-supergravity formalism that applies in some such cases
Asymptotic freedom in extended conformal supergravities
International Nuclear Information System (INIS)
Fradkin, E.S.; Tseytlin, A.A.
1982-01-01
We present the calculation of the one-loop β-function in extended conformal supergravities. N = 1, 2, 3 theories (free or coupled to the Einstein supergravities) are found to the asymptotically free (like the N = 0 Weyl theory) while the N = 4 theory becomes finite under some plausible hypothesis. The results support the possibility to solve the problem of ghosts in these theories. The obtained sequence of SU(N) β-functions appears to be in remarkable correspondence with that for gauged O(N) supergravity theories. (orig.)
Unlocking the axion-dilaton in 5D supergravity
Czech Academy of Sciences Publication Activity Database
Raeymaekers, Joris; Van den Bleeken, D.
2014-01-01
Roč. 11, Nov (2014), s. 1-54 ISSN 1029-8479 R&D Projects: GA ČR(CZ) GA14-31689S Institutional support: RVO:68378271 Keywords : supergravity models * d-branes * m-theory * black holes in string theory Subject RIV: BE - Theoretical Physics Impact factor: 6.111, year: 2014 http://link.springer.com/article/10.1007%2FJHEP11%282014%29029
Non-gaussian inflationary shapes in G3 theories beyond Horndeski
International Nuclear Information System (INIS)
Fasiello, Matteo; Renaux-Petel, Sébastien
2014-01-01
We consider the possible signatures of a recently introduced class of healthy theories beyond Horndeski models on higher-order correlators of the inflationary curvature fluctuation. Despite the apparent large number and complexity of the cubic interactions, we show that the leading-order bispectrum generated by the Generalized Horndeski (also called G 3 ) interactions can be reduced to a linear combination of two well known k-inflationary shapes. We conjecture that said behavior is not an accident of the cubic order but a consequence dictated by the requirements on the absence of Ostrogradski instability, the general covariance and the linear dispersion relation in these theories
A quantum gravitational inflationary scenario in Bianchi-I spacetime
International Nuclear Information System (INIS)
Gupt, Brajesh; Singh, Parampreet
2013-01-01
We investigate the ϕ 2 inflationary model in the Bianchi-I spacetime using the effective spacetime description of loop quantum cosmology to understand the issues of the resolution of initial singularity, isotropization, effect of anisotropies on the amount of inflation, and the phase-space attractors in the presence of non-perturbative quantum gravitational modifications. A comparative analysis with the classical theory by including more general initial conditions than the ones previously considered in the latter is also performed. We show that, in general, the classical singularity is replaced by a bounce of the mean scale factor in loop quantum cosmology. Due to the underlying quantum geometric effects, the energy density of the inflaton and the anisotropic shear remain bounded throughout the non-singular evolution. Starting from arbitrary anisotropic initial conditions, a loop quantum universe isotropizes either before or soon after the onset of slow-roll inflation. We find a double attractor behavior in the phase-space dynamics of loop quantum cosmology, similar to the one in classical theory, but with some additional subtle features. Quantum modifications to the dynamical equations are such that, unlike the classical theory, the amount of inflation does not monotonically depend on the initial anisotropy in loop quantum cosmology. Our results suggest that a viable non-singular inflationary model can be constructed from highly anisotropic initial conditions in the Planck regime. (paper)
Estimation of Inflationary Expectations and the Effectiveness of Inflation Targeting Strategy
Directory of Open Access Journals (Sweden)
Amalia CRISTESCU
2011-02-01
Full Text Available The credibility and accountability of a central bank, acting in an inflation targeting regime, are essential because they allow a sustainable anchoring of the inflationary anticipation of economic agents. Their decisions and behavior will increasingly be grounded on information provided by the central bank, especially if it shows transparency in the process of communicating with the public. Thus, inflationary anticipations are one of the most important channels through which the monetary policy affects the economic activity. They are crucial in the formation of the consumer prices among producers and traders, especially since it is relatively expensive for the economic agents to adjust their prices at short intervals. That is why many central banks use response functions containing inflationary anticipations, in their inflation targeting models. The most frequently problem in relation to these anticipations is that they are based on the assumption of optimal forecasts of future inflation, which are, implicitly, rational anticipations. In fact, the economic agents’ inflationary anticipations are most often adaptive or even irrational. Thus, rational anticipations cannot be used to estimate equations for the Romanian economy because the agents who form their expectations do not have sufficient information and an inflationary environment stable enough to fully anticipate the inflation evolution. The inflation evolution in the Romanian economy helps to calculate adaptive forecasts for which the weight of the "forward looking" component has to be rather important. The economic agents form their inflation expectations for periods of time that, usually, coincide with a production cycle (one year and consider the official and unofficial inflation forecasts present on the market in order to make strategic decisions. Thus, in recent research on inflation modeling, actual inflationary anticipations of economic agents which are revealed based on national
Supersymmetric solutions of N =(1 ,1 ) general massive supergravity
Deger, N. S.; Nazari, Z.; Sarıoǧlu, Ö.
2018-05-01
We construct supersymmetric solutions of three-dimensional N =(1 ,1 ) general massive supergravity (GMG). Solutions with a null Killing vector are, in general, pp-waves. We identify those that appear at critical points of the model, some of which do not exist in N =(1 ,1 ) new massive supergravity (NMG). In the timelike case, we find that many solutions are common with NMG, but there is a new class that is genuine to GMG, two members of which are stationary Lifshitz and timelike squashed AdS spacetimes. We also show that in addition to the fully supersymmetric AdS vacuum, there is a second AdS background with a nonzero vector field that preserves 1 /4 supersymmetry.
Possible role of Berry phase in inflationary cosmological perturbations
International Nuclear Information System (INIS)
Pal, Barun Kumar; Pal, Supratik; Basu, B
2012-01-01
Here we have derived a cosmological analogue of Berry phase by obtaining the corresponding wavefunction for the system of inflationary cosmological perturbations solving the Schrodinger equation. We have further shown that cosmological Berry phase can be related inflationary observable parameters. As a result one can, atleast in principle, establish a supplementary probe of inflationary cosmology through the measurement of the associated Berry phase. But we do not make any strong comment on this.
Spectrum of perturbations in anisotropic inflationary universe with vector hair
Energy Technology Data Exchange (ETDEWEB)
Himmetoglu, Burak, E-mail: burak@physics.umn.edu [School of Physics and Astronomy, University of Minnesota, 116 Church Street S.E., Minneapolis, MN 55455 (United States)
2010-03-01
We study both the background evolution and cosmological perturbations of anisotropic inflationary models supported by coupled scalar and vector fields. The models we study preserve the U(1) gauge symmetry associated with the vector field, and therefore do not possess instabilities associated with longitudinal modes (which instead plague some recently proposed models of vector inflation and curvaton). We first intoduce a model in which the background anisotropy slowly decreases during inflation; we then confirm the stability of the background solution by studying the quadratic action for all the perturbations of the model. We then compute the spectrum of the h{sub ×} gravitational wave polarization. The spectrum we find breaks statistical isotropy at the largest scales and reduces to the standard nearly scale invariant form at small scales. We finally discuss the possible relevance of our results to the large scale CMB anomalies.
Inflationary paradigm after Planck 2013
Energy Technology Data Exchange (ETDEWEB)
Guth, Alan H., E-mail: guth@ctp.mit.edu [Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Kaiser, David I., E-mail: dikaiser@mit.edu [Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Nomura, Yasunori, E-mail: ynomura@berkeley.edu [Berkeley Center for Theoretical Physics, Department of Physics, and Theoretical Physics Group, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States)
2014-06-02
Models of cosmic inflation posit an early phase of accelerated expansion of the universe, driven by the dynamics of one or more scalar fields in curved spacetime. Though detailed assumptions about fields and couplings vary across models, inflation makes specific, quantitative predictions for several observable quantities, such as the flatness parameter (Ω{sub k}=1−Ω) and the spectral tilt of primordial curvature perturbations (n{sub s}−1=dlnP{sub R}/dlnk), among others—predictions that match the latest observations from the Planck satellite to very good precision. In the light of data from Planck as well as recent theoretical developments in the study of eternal inflation and the multiverse, we address recent criticisms of inflation by Ijjas, Steinhardt, and Loeb. We argue that their conclusions rest on several problematic assumptions, and we conclude that cosmic inflation is on a stronger footing than ever before.
Inflationary paradigm after Planck 2013
International Nuclear Information System (INIS)
Guth, Alan H.; Kaiser, David I.; Nomura, Yasunori
2014-01-01
Models of cosmic inflation posit an early phase of accelerated expansion of the universe, driven by the dynamics of one or more scalar fields in curved spacetime. Though detailed assumptions about fields and couplings vary across models, inflation makes specific, quantitative predictions for several observable quantities, such as the flatness parameter (Ω k =1−Ω) and the spectral tilt of primordial curvature perturbations (n s −1=dlnP R /dlnk), among others—predictions that match the latest observations from the Planck satellite to very good precision. In the light of data from Planck as well as recent theoretical developments in the study of eternal inflation and the multiverse, we address recent criticisms of inflation by Ijjas, Steinhardt, and Loeb. We argue that their conclusions rest on several problematic assumptions, and we conclude that cosmic inflation is on a stronger footing than ever before.
Inflationary dynamics of kinetically-coupled gauge fields
DEFF Research Database (Denmark)
Ferreira, Ricardo J. Z.; Ganc, Jonathan
2015-01-01
We investigate the inflationary dynamics of two kinetically-coupled massless U(1) gauge fields with time-varying kinetic-term coefficients. Ensuring that the system does not have strongly coupled regimes shrinks the parameter space. Also, we further restrict ourselves to systems that can be quant......We investigate the inflationary dynamics of two kinetically-coupled massless U(1) gauge fields with time-varying kinetic-term coefficients. Ensuring that the system does not have strongly coupled regimes shrinks the parameter space. Also, we further restrict ourselves to systems that can...... be quantized using the standard creation, annihilation operator algebra. This second constraint limits us to scenarios where the system can be diagonalized into the sum of two decoupled, massless, vector fields with a varying kinetic-term coefficient. Such a system might be interesting for magnetogenesis...... because of how the strong coupling problem generalizes. We explore this idea by assuming that one of the gauge fields is the Standard Model U(1) field and that the other dark gauge field has no particles charged under its gauge group. We consider whether it would be possible to transfer a magnetic field...
Perturbative and global anomalies in supergravity theories
International Nuclear Information System (INIS)
Sezgin, E.
1986-09-01
Perturbative and global anomalies in supergravity theories are reviewed. The existence of a matter and gauge coupled supergravity theory in six dimensions with E 6 xE 7 xU(1) symmetry and highly nontrivial anomaly cancellations is emphasised. The possible string origin of this theory is posed as an open problem, study of which may lead to discovery of new ways to construct/compactify heterotic superstrings. (author)
Inflationary trispectrum from graviton exchange
DEFF Research Database (Denmark)
Seery, David; Sloth, Martin Snoager; Vernizzi, Filippo
2009-01-01
We compute the connected four-point correlation function of the primordial curvature perturbation generated during inflation with standard kinetic terms, where the correlation is established via exchange of a graviton between two pairs of scalar fluctuations. Any such correlation yields a contrib......We compute the connected four-point correlation function of the primordial curvature perturbation generated during inflation with standard kinetic terms, where the correlation is established via exchange of a graviton between two pairs of scalar fluctuations. Any such correlation yields...... where the momentum of the graviton which is exchanged becomes much smaller than the external momenta. We conclude that the total non-linearity parameter generated by single-field models of slow-roll inflation is at maximum tauNL ~ r....
The gravitino-overproduction problem in inflationary universe
Energy Technology Data Exchange (ETDEWEB)
Kawasaki, M. [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Takahashi, F. [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research]|[Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe
2006-05-15
We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field {phi} generically acquires (effective) non-vanishing auxiliary field G{sup (eff)}{sub {phi}}, if the Kaehler potential is non-minimal. The inflaton field then decays into a pair of the gravitinos. We extensively study the cosmological constraints on G{sup (eff)}{sub {phi}} for a wide range of the gravitino mass. For many inflation models we explicitly estimate G{sup (eff)}{sub {phi}}, and show that the gravitino-overproduction problem severely constrains the inflation models, unless such an interaction as K={kappa}/2 vertical stroke {phi} vertical stroke {sup 2}z{sup 2}+h.c. is suppressed (here z is the field responsible for the supersymmetry breaking). We find that many of them are already excluded or on the verge of, if {kappa}{proportional_to}O(1). (Orig.)
International Nuclear Information System (INIS)
Saez, D.
1987-01-01
In this work the metric is coupled with a scalar field phi in a simple way. Although this coupling becomes problematic because the energy density of phi appears to be unbounded from below, it is displayed as a very simple coupling leading to a nonsingular cosmological model with an early antigravity regime. A basic study of the inflationary period and various suggestions are presented
Quantum gravity extension of the inflationary scenario.
Agullo, Ivan; Ashtekar, Abhay; Nelson, William
2012-12-21
Since the standard inflationary paradigm is based on quantum field theory on classical space-times, it excludes the Planck era. Using techniques from loop quantum gravity, the paradigm is extended to a self-consistent theory from the Planck scale to the onset of slow roll inflation, covering some 11 orders of magnitude in energy density and curvature. This preinflationary dynamics also opens a small window for novel effects, e.g., a source for non-Gaussianities, which could extend the reach of cosmological observations to the deep Planck regime of the early Universe.
Euclidean approach to the inflationary universe
International Nuclear Information System (INIS)
Hawking, S.W.
1983-01-01
The aim of this article is to show how the Euclidean approach can be used to study the inflationary universe. Although this formulation may appear counterintuitive in some respects, it has the advantage that it defines a definite quantum state and provides a framework for calculating quantities of interest such as correlation functions or tunnelling probabilities. By contrast, in the more usual approach in real Lorentzian spacetime, it is not so clear what the quantum state should be or how to evaluate such quantities. (author)
Toldo, C.
2014-01-01
This thesis is devoted to the analysis of asymptotically Anti-de Sitter (AdS) black holes arising as solutions of theories of gauged Supergravity in four spacetime dimensions. After a brief recap of the main features of gauged supergravity, the first part of the thesis deals with the explicit
Thorne, Ben; Fujita, Tomohiro; Hazumi, Masashi; Katayama, Nobuhiko; Komatsu, Eiichiro; Shiraishi, Maresuke
2018-02-01
A detection of B-mode polarization of the cosmic microwave background (CMB) anisotropies would confirm the presence of a primordial gravitational wave background (GWB). In the inflation paradigm, this would be an unprecedented probe of the energy scale of inflation as it is directly proportional to the power spectrum of the GWB. However, similar tensor perturbations can be produced by the matter fields present during inflation, breaking the simple relationship between energy scale and the tensor-to-scalar ratio r . It is therefore important to find ways of distinguishing between the generation mechanisms of the GWB. Without doing a full model selection, we analyze the detectability of a new axion-S U (2 ) gauge field model by calculating the signal-to-noise ratio of future CMB and interferometer observations sensitive to the chirality of the tensor spectrum. We forecast the detectability of the resulting CMB temperature and B-mode (TB) or E-mode and B-mode (EB) cross-correlation by the LiteBIRD satellite, considering the effects of residual foregrounds, gravitational lensing, and assess the ability of such an experiment to jointly detect primordial TB and EB spectra and self-calibrate its polarimeter. We find that LiteBIRD will be able to detect the chiral signal for r*>0.03 , with r* denoting the tensor-to-scalar ratio at the peak scale, and that the maximum signal-to-noise ratio for r*advanced stage of a LISA-like mission, which is designed to be sensitive to the intensity and polarization of the GWB. We find that such experiments would complement CMB observations as they would be able to detect the chirality of the GWB with high significance on scales inaccessible to the CMB. We conclude that CMB two-point statistics are limited in their ability to distinguish this model from a conventional vacuum fluctuation model of GWB generation, due to the fundamental limits on their sensitivity to parity violation. In order to test the predictions of such a model as
Classical behavior of a scalar field in the inflationary universe
International Nuclear Information System (INIS)
Sasaki, Misao; Nambu, Yasusada; Nakao, Ken-ichi.
1987-09-01
Extending the coarse-graining approach of Starobinsky, we formulate a theory to deal with the dynamics of a scalar field in inflationary universe models. We find a set of classical Langevin equations which describes the large scale behavior of the scalar field, provided that the coarse-grained size is greater than the effective compton wavelength of the scalar field. The corresponding Fokker-Planck equation is also derived which is defined on the phase space of the scalar field. We show that our theory is essentially equivalent to the one-loop field theory in de Sitter space and reduces to that of Starobinsky in a strong limit of the slow roll-over condition. Analysis of a simple Higgs potential model is done and the implications are discussed. (author)
Inflationary magnetogenesis with added helicity: constraints from non-Gaussianities
Caprini, Chiara; Chiara Guzzetti, Maria; Sorbo, Lorenzo
2018-06-01
In previous work (Caprini and Sorbo 2014 J. Cosmol. Astropart. Phys. JCAP10(2014)056), two of us have proposed a model of inflationary magnetogenesis based on a rolling auxiliary field able both to account for the magnetic fields inferred by the (non) observation of gamma-rays from blazars, and to start the galactic dynamo, without incurring in any strong coupling or strong backreaction regime. Here we evaluate the correction to the scalar spectrum and bispectrum with respect to single-field slow-roll inflation generated in that scenario. The strongest constraints on the model originate from the non-observation of a scalar bispectrum. Nevertheless, even when those constraints are taken into consideration, the scenario can successfully account for the observed magnetic fields as long as the energy scale of inflation is smaller than GeV, under some conditions on the slow roll of the auxiliary scalar field.
Supergravity and the quest for a unified theory
International Nuclear Information System (INIS)
Ferrara, S.
1995-01-01
The foundation of supergravity and research in its subsequent developments is described. Special emphasis is placed on the impact of supergravity on the search for a unified theory of fundamental interactions. (author)
Supersymmetry, superfields and supergravity: An introduction
International Nuclear Information System (INIS)
Srivastava, P.P.
1986-01-01
This book is a self-contained introduction to the subject of supersymmetry. The algebras of supersymmetry and the R-symmetry generators are explained using a simple field theory model. The realisations of this algebra on one-particle states and on a supermultiplet of component fields are then discussed. There is a detailed description of the Wess-Zumino model, with discussion of the realisation of R-symmetry and supermultiplets of currents and anomalies. Detailed treatment of the realisation of the algebra on superspace and superfields is applied to the Yang-Mills theory in interaction with matter. The possibility of spontaneously broken symmetries is introduced before non-Abelian supersymmetric gauge theories are constructed. Superfield propagators are derived as the Green functions of the corresponding equations of motion and the power of superfield perturbation theory is illustrated. Finally local supersymmetry and the supergravity Lagrangian are introduced with a discussion of gravity-induced supersymmetry breaking and the super-Higgs effect. Emphasis is placed on developing a physical understanding of the mathematical formalism and numerous problems are included to help develop the reader's understanding
Constraining brane inflationary magnetic field from cosmoparticle physics after Planck
International Nuclear Information System (INIS)
Choudhury, Sayantan
2015-01-01
In this article, I have studied the cosmological and particle physics constraints on a generic class of large field (|Δϕ|>M_p) and small field (|Δϕ|< M_p) models of brane inflationary magnetic field from: (1) tensor-to-scalar ratio (r), (2) reheating, (3) leptogenesis and (4) baryogenesis in case of Randall-Sundrum single braneworld gravity (RSII) framework. I also establish a direct connection between the magnetic field at the present epoch (B_0) and primordial gravity waves (r), which give a precise estimate of non-vanishing CP asymmetry (ϵ_C_P) in leptogenesis and baryon asymmetry (η_B) in baryogenesis scenario respectively. Further assuming the conformal invariance to be restored after inflation in the framework of RSII, I have explicitly shown that the requirement of the sub-dominant feature of large scale coherent magnetic field after inflation gives two fold non-trivial characteristic constraints- on equation of state parameter (w) and the corresponding energy scale during reheating (ρ_r_h"1"/"4) epoch. Hence giving the proposal for avoiding the contribution of back-reaction from the magnetic field I have established a bound on the generic reheating characteristic parameter (R_r_h) and its rescaled version (R_s_c), to achieve large scale magnetic field within the prescribed setup and further apply the CMB constraints as obtained from recently observed Planck 2015 data and Planck+BICEP2+Keck Array joint constraints. Using all these derived results I have shown that it is possible to put further stringent constraints on various classes of large and small field inflationary models to break the degeneracy between various cosmological parameters within the framework of RSII. Finally, I have studied the consequences from two specific models of brane inflation- monomial and hilltop, after applying the constraints obtained from inflation and primordial magnetic field.
Hamilton-Jacobi formalism to warm inflationary scenario
Sayar, K.; Mohammadi, A.; Akhtari, L.; Saaidi, Kh.
2017-01-01
The Hamilton-Jacobi formalism as a powerful method is being utilized to reconsider the warm inflationary scenario, where the scalar field as the main component driving inflation interacts with other fields. Separating the context into strong and weak dissipative regimes, the goal is followed for two popular functions of Γ . Applying slow-rolling approximation, the required perturbation parameters are extracted and, by comparing to the latest Planck data, the free parameters are restricted. The possibility of producing an acceptable inflation is studied where the result shows that for all cases the model could successfully suggest the amplitude of scalar perturbation, scalar spectral index, its running, and the tensor-to-scalar ratio.
Global structure of the inflationary Universe
International Nuclear Information System (INIS)
Goncharov, A.S.; Linde, A.D.
1987-01-01
The global structure of the Universe is analyzed within the framework of the haotic inflation scenario. It is shown that under certain conditions inflation of the Universe in accordance with this scenario has no the end and may not have the beginning. Consequently, a large part of the physical volume of the Universe should always be in a state of inflation at a density of the order of the Planck density. During inflation the Universe separates into regions of exponentially large sizes. Within these regions all possible types of metastable vacuum states and all possible types of compactification, consistent with the presence of inflation are realized. The investigation is performed by employing the diffusion equation for a fluctuating scalar field in the inflationary Universe
Tensor ghosts in the inflationary cosmology
International Nuclear Information System (INIS)
Clunan, Tim; Sasaki, Misao
2010-01-01
Theories with curvature-squared terms in the action are known to contain ghost modes in general. However, if we regard curvature-squared terms as quantum corrections to the original theory, the emergence of ghosts may be simply due to the perturbative truncation of a full non-perturbative theory. If this is the case, there should be a way to live with ghosts. In this paper, we take the Euclidean path integral approach, in which ghost degrees of freedom can be, and are integrated out in the Euclideanized spacetime. We apply this procedure to Einstein gravity with a Weyl curvature-squared correction in the inflationary background. We find that the amplitude of tensor perturbations is modified by a term of O(α 2 H 2 ) where α 2 is a coupling constant in front of the Weyl-squared term and H is the Hubble parameter during inflation.
Renormalization of the inflationary perturbations revisited
Markkanen, Tommi
2018-05-01
In this work we clarify aspects of renormalization on curved backgrounds focussing on the potential ramifications on the amplitude of inflationary perturbations. We provide an alternate view of the often used adiabatic prescription by deriving a correspondence between the adiabatic subtraction terms and traditional renormalization. Specifically, we show how adiabatic subtraction can be expressed as a set of counter terms that are introduced by redefining the bare parameters of the action. Our representation of adiabatic subtraction then allows us to easily find other renormalization prescriptions differing only in the finite parts of the counter terms. As our main result, we present for quadratic inflation how one may consistently express the renormalization of the spectrum of perturbations from inflation as a redefinition of the bare cosmological constant and Planck mass such that the observable predictions coincide with the unrenormalized result.
Background harmonic superfields in N=2 supergravity
International Nuclear Information System (INIS)
Zupnik, B.M.
1998-01-01
A modification of the harmonic superfield formalism in D=4, N=2 supergravity using a subsidiary condition of covariance under the background supersymmetry with a central charge (B-covariance) is considered. Conservation of analyticity together with the B-covariance leads to the appearance of linear gravitational superfields. Analytic prepotentials arise in a decomposition of the background linear superfields in terms of spinor coordinates and transform in a nonstandard way under the background supersymmetry. The linear gravitational superfields can be written via spinor derivatives of nonanalytic spinor prepotentials. The perturbative expansion of supergravity action in terms of the B-covariant superfields and the corresponding version of the differential-geometric formalism are considered. We discuss the dual harmonic representation of the linearized extended supergravity, which corresponds to the dynamical condition of Grassmann analyticity
High energy scattering in gravity and supergravity
Giddings, Steven B; Andersen, Jeppe R
2010-01-01
We investigate features of perturbative gravity and supergravity by studying scattering in the ultraplanckian limit, and sharpen arguments that the dynamics is governed by long-distance physics. A simple example capturing aspects of the eikonal resummation suggests why short distance phenomena and in particular divergences or nonrenormalizability do not necessarily play a central role in this regime. A more profound problem is apparently unitarity. These considerations can be illustrated by showing that known gravity and supergravity amplitudes have the same long-distance behavior, despite the extra light states of supergravity, and this serves as an important check on long-range dynamics in a context where perturbative amplitudes are finite. We also argue that these considerations have other important implications: they obstruct probing the conjectured phenomenon of asymptotic safety through a physical scattering process, and gravity appears not to reggeize. These arguments sharpen the need to find a nonpert...
Geometries inherent to N=1 supergravities
International Nuclear Information System (INIS)
Galperin, A.S.; Ogievetsky, V.I.; Sokatchev, E.S.
1981-01-01
The first part of the talk is devoted to a consideration of linearized N=1 supergravities. The second main part deals with complex geometries inherent to different N=1 supergravities. A special attention is paid to a new version with local symmetry. It is connected to the special nonminimal case (n=0) having a remarkable property of supervolume preservation in Csup(4.4) superspace. Therefore the superdeterminant of change of variables from left to right-handed Rsup(4.4) parametrization is a dimensionless scalar. This geometric invariant has to be constrained to obtain an action. Solving such a constraint on vector and spinor prepotentials in Wess-Zumino gauge one obtains the new supergravity with 12+12 fields and local symmetry. A possible relaxation of this constraint is briefly considered (16+16 fields version) [ru
Euclidean supergravity and multi-centered solutions
Directory of Open Access Journals (Sweden)
W.A. Sabra
2017-04-01
Full Text Available In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein–Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D=5, N=2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein–Maxwell multi-centered solutions are also presented.
A problem of the QCD axion in supergravity
International Nuclear Information System (INIS)
Endo, M.; Takahashi, F.; Tokyo Univ.; Yanagida, T.T.; Tokyo Univ.
2007-12-01
We point out that the QCD axion generally couples to all the gauge fields in nature through the Super-Weyl, Kaehler and sigma-model anomalies in supergravity. If supersymmetry is dynamically broken by the hidden-sector gauge interactions, the axion potential receives corrections due to the instanton in the hidden sector. We show that the supersymmetry breaking models are tightly constrained for the Peccei-Quinn mechanism to successfully solve the strong CP problem. In particular, the gravity mediation turns out to be strongly disfavored. (orig.)
Black-Hole Attractors in N=1 Supergravity
Andrianopoli, L; Ferrara, Sergio; Trigiante, M; Andrianopoli, Laura; Auria, Riccardo D'; Ferrara, Sergio; Trigiante, Mario
2007-01-01
We study the attractor mechanism for N=1 supergravity coupled to vector and chiral multiplets and compute the attractor equations of these theories. These equations may have solutions depending on the choice of the holomorphic symmetric matrix f_{\\Lambda\\Sigma} which appears in the kinetic lagrangian of the vector sector. Models with non trivial electric-magnetic duality group which have or have not attractor behavior are exhibited. For a particular class of models, based on an N=1 reduction of homogeneous special geometries, the attractor equations are related to the theory of pure spinors.
Formulation of 11-dimensional supergravity in superspace
International Nuclear Information System (INIS)
Cremmer, E.; Ferrara, S.
1980-01-01
We formulate on-shell 11-dimensional supergravity in superspace and express its equations of motion in terms of purely geometrical quantities. All torsion and curvature components are solved in terms of a single superfield Wsub(rstu), totally antisymmetric in its (flat vector) indices. The dimensional reduction of this formulation is expected to be related to the superspace formulation of N = 8 extended supergravity and might explain the origin of the hidden (local) SU(8) and (global) E 7 symmetries present in this theory. (orig.)
Goldstino superfields in N=2 supergravity
Energy Technology Data Exchange (ETDEWEB)
Kuzenko, Sergei M.; McArthur, Ian N. [School of Physics and Astrophysics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Tartaglino-Mazzucchelli, Gabriele [Instituut voor Theoretische Fysica, KU Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2017-05-11
We present off-shell N=2 supergravity actions, which exhibit spontaneously broken local supersymmetry and allow for de Sitter vacua for certain values of the parameters. They are obtained by coupling the standard N=2 supergravity-matter systems to the Goldstino superfields introduced in arXiv:1105.3001 and arXiv:1607.01277 in the rigid supersymmetric case. These N=2 Goldstino superfields include nilpotent chiral and linear supermultiplets. We also describe a new reducible N=1 Goldstino supermultiplet.
Generation of composite operators in supergravity
International Nuclear Information System (INIS)
Abdalla, E.
1984-07-01
The author discusses the generation of quantum composite operators in two and higher dimensions. In two dimensions the problem is discussed in detail, and the supergravity fields, trivial at the beginning, acquire the status of independent fields, non trivial features being obtained as consequence. In higher dimensions one is led to non compact symmetry groups when dealing with supergravity. The symmetry SU(p,q) is discussed; quantization presents several problems. In one case, p=q, it is possible to obtain a prescription leading to finite results, with a quantization procedure breaking the symmetry to SU(p) X SU(q). (Auth.)
Aspects of Weyl Supergravity arXiv
Ferrara, Sergio; Lust, Dieter
In this paper we study the spectrum of all conformal, ${\\cal N}$-extended supergravities (${\\cal N}=1,2,3,4$) in four space-time dimensions. When these theories are obtained as massless limit of Einstein plus Weyl$^2$supergravity, the appropriate counting of the enhanced gauge symmetries allow us to derive the massless spectrum which consist of a dipole ghost graviton multiplet, a ${\\cal N}$-fold tripole ghost gravitino, the third state belonging to a spin 3/2 multiplet and a residual vector multiplet present for non-maximal ${\\cal N}<4$ theories. These theories are not expected to have a standard gravity holographic dual in five dimensions.
Anti-D3 branes and moduli in non-linear supergravity
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.
International Nuclear Information System (INIS)
Gato, B.; Leon, J.; Ramon-Medrano, M.
1984-01-01
We present a model for a SUSY GUT coupled to N=1 supergravity in which local supersymmetry breaks down in the gauge singlet sector. The constraints for the model to be physically acceptable are incompatible with inflation. The simultaneous breaking of local supersymmetry and gauge symmetry is proposed as a good prospect for inflation. (orig.)
Direct gauge mediation of uplifted metastable supersymmetry breaking in supergravity
International Nuclear Information System (INIS)
Maru, Nobuhito
2010-01-01
We propose a direct gauge mediation model based on an uplifted metastable supersymmetry (SUSY) breaking coupled to supergravity. A constant superpotential plays an essential role to fix the moduli as well as breaking SUSY and R symmetry and the cancellation of the cosmological constant. Gaugino masses are generated at leading order of SUSY breaking scale, and comparable to the sfermion masses as in the ordinary gauge mediation. The Landau pole problem for QCD coupling can be easily solved since more than half of messengers become superheavy, which are heavier than the grand unified theory (GUT) scale.
Lagrangians of N=2 supergravity-matter systems
International Nuclear Information System (INIS)
Wit, B. de; Proeyen, A. van; Lauwers, P.G.
1984-12-01
We present explicit expressions for general actions of vector and scalar multiplets coupled to N=2 supergravity. We outline their construction which is based on the superconformal tensor calculus. The vector multiplets may be associated with a gauge group G which may also act on the scalar multiplets. The latter are naturally described in terms of quaternions; in the simplest case their kinetic terms define a nonlinear sigma model of a quaternionic projective space. We give an extension of the vector multiplet action which is not obtained from a chiral superspace density, and contains a Chern-Simons-type term. Transformation rules are given and the conditions for supersymmetry breaking are defined. (orig.)
Kaluza-Klein supergravity in ten dimensions
International Nuclear Information System (INIS)
Huq, M.; Namazie, M.A.
1983-11-01
We construct a massive version of N=2 supergravity in ten dimensions by compactification of the eleven dimensional, N=1 theory. This theory describes the usual N=2 massless super-multiplet, in addition to which there is an infinite tower of massive, charged N=2 supermultiplets. (author)
Vacuum state supersymmetry in d=11 supergravity
International Nuclear Information System (INIS)
Vasilevich, D.V.
1987-01-01
Supersymmetry of vacuum state in d=11 supergravity is considered. Proceeding on sufficiently general assumptions relatively superformation parameter only Freud-Rubin type solutions may possess supersymmetries. To obtain this result no restrictions on the form of superformation parameter, supealgebra of vacuum global supersymmetry and the form of boson fields were imposed
Gauged supergravities in various spacetime dimensions
Energy Technology Data Exchange (ETDEWEB)
Weidner, M.
2006-12-15
In this thesis we study the gaugings of extended supergravity theories in various space-time dimensions. These theories describe the low-energy limit of non-trivial string compactifications. For each theory under consideration we work out all possible gaugings that are compatible with supersymmetry. They are parameterized by the so-called embedding tensor which is a group theoretical object that has to satisfy certain representation constraints. This embedding tensor determines all couplings in the gauged theory that are necessary to preserve gauge invariance and supersymmetry. The concept of the embedding tensor and the general structure of the gauged supergravities are explained in detail. The methods are then applied to the half-maximal (N=4) supergravities in d=4 and d=5 and to the maximal supergravities in d=2 and d=7. Examples of particular gaugings are given. Whenever possible, the higher-dimensional origin of these theories is identified and it is shown how the compactification parameters like fluxes and torsion are contained in the embedding tensor. (orig.)
Generating geodesic flows and supergravity solutions
Bergshoeff, E.; Chemissany, W.; Ploegh, A.; Trigiante, M.; Van Riet, T.
2009-01-01
We consider the geodesic motion on the symmetric moduli spaces that arise after timelike and spacellike reductions of supergravity theories. The geodesics correspond to timelike respectively spacelike p-brane Solutions when they are lifted over a p-dimensional flat space. In particular, we consider
Supergravity duals of matrix string theory
International Nuclear Information System (INIS)
Morales, Jose F.; Samtleben, Henning
2002-01-01
We study holographic duals of type II and heterotic matrix string theories described by warped AdS 3 supergravities. By explicitly solving the linearized equations of motion around near horizon D-string geometries, we determine the spectrum of Kaluza-Klein primaries for type I, II supergravities on warped AdS 3 xS 7 . The results match those coming from the dual two-dimensional gauge theories living on the D-string worldvolumes. We briefly discuss the connections with the N=(8,8), N=(8,0) orbifold superconformal field theories to which type IIB/heterotic matrix strings flow in the infrared. In particular, we associate the dimension (h,h-bar) (32,32) twisted operator which brings the matrix string theories out from the conformal point (R; 8 ) N /S N with the dilaton profile in the supergravity background. The familiar dictionary between masses and 'scaling' dimensions of field and operators are modified by the presence of non-trivial warp factors and running dilatons. These modifications are worked out for the general case of domain wall/QFT correspondences between supergravities on warped AdS d+1 xS q geometries and super Yang-Mills theories with 16 supercharges. (author)
Extremal black holes in N=2 supergravity
Katmadas, S.
2011-01-01
An explanation for the entropy of black holes has been an outstanding problem in recent decades. A special case where this is possible is that of extremal black holes in N=2 supergravity in four and five dimensions. The best developed case is for black holes preserving some supersymmetry (BPS),
Local supertwistors and N=2 conformal supergravity
International Nuclear Information System (INIS)
Merkulov, S.A.
1989-01-01
N = 2 sypersymmetric extension of the local twistor theory is formulated. A supertwistor superconnection determined by the superconformal structure of the base superspace is introduced on the bundle of N = 2 local supertwistors. It is proved that the Yang - Mills equations for this superconnection coincide exactly with the Bach equations describing the dynamics of N 2 conformal supergravity
Kaluza-Klein theories and supergravity
CERN. Geneva. Audiovisual Unit
1986-01-01
In all recent attempts at a unified description of all fundamental interactions, the idea of introducing extra dimensions has played an important role. This idea becomes even more attractive when combined with the more recent concepts of supersymmetry and supergravity. These topics as well as more recent developments will be reviewed at an introductory level in these lectures.
Graded-Lie-algebra cohomology and supergravity
International Nuclear Information System (INIS)
D'Auria, R.; Fre, P.; Regge, T.
1980-01-01
Detailed explanations of the cohomology invoked in the group-manifold approach to supergravity is given. The Chevalley cohomology theory of Lie algebras is extended to graded Lie algebras. The scheme of geometrical theories is enlarged so to include cosmological terms and higher powers of the curvature. (author)
Complex linear Goldstino superfield and supergravity
Energy Technology Data Exchange (ETDEWEB)
Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia)
2015-10-01
The complex linear Goldstino superfield was proposed in http://arxiv.org/abs/1102.3042 for the cases of global and local four-dimensional N=1 supersymmetry. Here we make use of this superfield to construct a supergravity action which is invariant under spontaneously broken local N=1 supersymmetry and has a positive cosmological constant for certain values of the parameters.
Possible signatures of the inflationary particle content: spin-2 fields
Energy Technology Data Exchange (ETDEWEB)
Biagetti, Matteo [Institute of Physics, Universiteit van Amsterdam, Science Park, Amsterdam, 1098XH The Netherlands (Netherlands); Dimastrogiovanni, Emanuela [CERCA and Department of Physics, Case Western Reserve University, Cleveland, OH, 44106 (United States); Fasiello, Matteo, E-mail: m.biagetti@uva.nl, E-mail: emanuela1573@gmail.com, E-mail: matteorf@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA, 94306 (United States)
2017-10-01
We study the imprints of a massive spin-2 field on inflationary observables, and in particular on the breaking of consistency relations. In this setup, the minimal inflationary field content interacts with the massive spin-2 field through dRGT interactions, thus guaranteeing the absence of Boulware-Deser ghostly degrees of freedom. The unitarity requirement on spinning particles, known as Higuchi bound, plays a crucial role for the size of the observable signal.
Higgs vacuum stability and inflationary dynamics after BICEP2 and PLANCK dust polarisation data
International Nuclear Information System (INIS)
Bhattacharya, Kaushik; Chakrabortty, Joydeep; Das, Suratna; Mondal, Tanmoy
2014-01-01
If the recent detection of B-mode polarization of the Cosmic Microwave Background by BICEP2 observations, withstand the test of time after the release of recent PLANCK dust polarisation data, then it would surprisingly put the inflationary scale near Grand Unification scale if one considers single-field inflationary models. On the other hand, Large Hadron Collider has observed the elusive Higgs particle whose presently observed mass can lead to electroweak vacuum instability at high scale (∼ O(10 10 ) GeV). In this article, we seek for a simple particle physics model which can simultaneously keep the vacuum of the theory stable and yield high-scale inflation successfully. To serve our purpose, we extend the Standard Model of particle physics with a U(1) B-L gauged symmetry which spontaneously breaks down just above the inflationary scale. Such a scenario provides a constrained parameter space where both the issues of vacuum stability and high-scale inflation can be successfully accommodated. The threshold effect on the Higgs quartic coupling due to the presence of the heavy inflaton field plays an important role in keeping the electroweak vacuum stable. Furthermore, this scenario is also capable of reheating the universe at the end of inflation. Though the issues of Dark Matter and Dark Energy, which dominate the late-time evolution of our universe, cannot be addressed within this framework, this model successfully describes the early universe dynamics according to the Big Bang model
Narrowing the window of inflationary magnetogenesis
Energy Technology Data Exchange (ETDEWEB)
Markkanen, Tommi [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Nurmi, Sami [Department of Physics, University of Jyväskylä, P.O. Box 35 (YFL), FI-40014 University of Jyväskylä (Finland); Räsänen, Syksy [Department of Physics and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FIN-00014 University of Helsinki, Finland and Department of Physics, Kobe University, Kobe 657-8501 (Japan); Vennin, Vincent, E-mail: tommi.markkanen@kcl.ac.uk, E-mail: sami.t.nurmi@jyu.fi, E-mail: syksy.rasanen@iki.fi, E-mail: vincent.vennin@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)
2017-06-01
We consider inflationary magnetogenesis where the conformal symmetry is broken by the term f {sup 2}(φ) F {sub αβ} F {sup αβ}. We assume that the magnetic field power spectrum today between 0.1 and 10{sup 4} Mpc is a power law, with upper and lower limits from observation. This fixes f to be close to a power law in conformal time in the window during inflation when the modes observed today are generated. In contrast to previous work, we do not make any assumptions about the form of f outside these scales. We cover all possible reheating histories, described by an average equation of state −1/3 < w-bar < 1. Requiring that strong coupling and large backreaction are avoided both at the background and perturbative level, we find the bound δ {sub B} {sub 0} < 5 ×10{sup −15} ( r /0.07){sup 1/2} κG for the magnetic field generated by inflation, where r is the tensor-to-scalar ratio and κ is a constant related to the form of f . This estimate has an uncertainty of one order of magnitude related to our approximations. The parameter κ is < 100, and values ∼> 1 require a highly fine-tuned form of f ; typical values are orders of magnitude smaller.
Taming the Runaway Problem of Inflationary Landscapes
Energy Technology Data Exchange (ETDEWEB)
Hall, Lawrence J.; Watari, Taizan; Yanagida, T. T.
2006-03-15
A wide variety of vacua, and their cosmological realization, may provide an explanation for the apparently anthropic choices of some parameters of particle physics and cosmology. If the probability on various parameters is weighted by volume, a flat potential for slow-roll inflation is also naturally understood, since the flatter the potential the larger the volume of the sub-universe. However, such inflationary landscapes have a serious problem, predicting an environment that makes it exponentially hard for observers to exist and giving an exponentially small probability for a moderate universe like ours. A general solution to this problem is proposed, and is illustrated in the context of inflaton decay and leptogenesis, leading to an upper bound on the reheating temperature in our sub-universe. In a particular scenario of chaotic inflation and non-thermal leptogenesis, predictions can be made for the size of CP violating phases, the rate of neutrinoless double beta decay and, in the case of theories with gauge-mediated weak scale supersymmetry, for the fundamental scale of supersymmetry breaking.
Inflationary power spectra with quantum holonomy corrections
Energy Technology Data Exchange (ETDEWEB)
Mielczarek, Jakub, E-mail: jakub.mielczarek@uj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, Cracow, 30-059 Poland (Poland)
2014-03-01
In this paper we study slow-roll inflation with holonomy corrections from loop quantum cosmology. It was previously shown that, in the Planck epoch, these corrections lead to such effects as singularity avoidance, metric signature change and a state of silence. Here, we consider holonomy corrections affecting the phase of cosmic inflation, which takes place away from the Planck epoch. Both tensor and scalar power spectra of primordial inflationary perturbations are computed up to the first order in slow-roll parameters and V/ρ{sub c}, where V is a potential of the scalar field and ρ{sub c} is a critical energy density (expected to be of the order of the Planck energy density). Possible normalizations of modes at short scales are discussed. In case the normalization is performed with use of the Wronskian condition applied to adiabatic vacuum, the tensor and scalar spectral indices are not quantum corrected in the leading order. However, by choosing an alternative method of normalization one can obtain quantum corrections in the leading order. Furthermore, we show that the holonomy-corrected equations of motion for tensor and scalar modes can be derived based on effective background metrics. This allows us to show that the classical Wronskian normalization condition is well defined for the cosmological perturbations with holonomy corrections.
The electric dipole moment of the neutron in low energy supergravity
International Nuclear Information System (INIS)
Polchinski, J.; Wise, M.B.
1983-01-01
We compute the electric dipole moment of the neutron in models with low energy supergravity or softly broken supersymmetry. The electric dipole moment is typically of order 10sup(-(22-23))e cm times CP-violating phases. We discuss the origin of these phases. (orig.)
Spontaneous SUSY breaking without R symmetry in supergravity
Maekawa, Nobuhiro; Omura, Yuji; Shigekami, Yoshihiro; Yoshida, Manabu
2018-03-01
We discuss spontaneous supersymmetry (SUSY) breaking in a model with an anomalous U (1 )A symmetry. In this model, the size of the each term in the superpotential is controlled by the U (1 )A charge assignment and SUSY is spontaneously broken via the Fayet-Iliopoulos of U (1 )A at the metastable vacuum. In the global SUSY analysis, the gaugino masses become much smaller than the sfermion masses, because an approximate R symmetry appears at the SUSY breaking vacuum. In this paper, we show that gaugino masses can be as large as gravitino mass, taking the supergravity effect into consideration. This is because the R symmetry is not imposed so that the constant term in the superpotential, which is irrelevant to the global SUSY analysis, largely contributes to the soft SUSY breaking terms in the supergravity. As the mediation mechanism, we introduce the contributions of the field not charged under U (1 )A and the moduli field to cancel the anomaly of U (1 )A. We comment on the application of our SUSY breaking scenario to the grand unified theory.
Phenomenology of R-parity violating minimal supergravity
International Nuclear Information System (INIS)
Bernhardt, M.A.
2008-02-01
We investigate in detail the low-energy spectrum of the P 6 violating minimal supergravity model using the SOFTSUSY spectrum code. We impose the experimental constraints from the measurement of the anomalous magnetic moment of the muon (g-2) μ , the b→sγ decay, the branching ration of B s →μ + μ - , as well as the mass bound from direct searches at colliders, in particular the Higgs boson and the lightest Chargino. We focus on regions, where the lightest neutralino is not the lightest supersymmetric particle (LSP). In these regions of parameter space either the lightest scalar tau or one of the sneutrinos is the LSP. We suggest four benchmark points with typical spectra and novel collider signatures which we investigate with a parton level Monte-Carlo simulation. We give an outlook for their detailed phenomenological analysis and simulation by the LHC collaborations, then including detector effects. In addition, we discuss a full Monte-Carlo simulation for single slepton production in association with a single top quark via an LQD type operator at the hadron colliders LHC and Tevatron. We present these results and show a predicted range of detectability for this process- for small couplings in various minimal supergravity models at the LHC. (orig.)
Phenomenology of R-parity violating minimal supergravity
Energy Technology Data Exchange (ETDEWEB)
Bernhardt, M.A.
2008-02-15
We investigate in detail the low-energy spectrum of the P{sub 6} violating minimal supergravity model using the SOFTSUSY spectrum code. We impose the experimental constraints from the measurement of the anomalous magnetic moment of the muon (g-2){sub {mu}}, the b{yields}s{gamma} decay, the branching ration of B{sub s}{yields}{mu}{sup +}{mu}{sup -}, as well as the mass bound from direct searches at colliders, in particular the Higgs boson and the lightest Chargino. We focus on regions, where the lightest neutralino is not the lightest supersymmetric particle (LSP). In these regions of parameter space either the lightest scalar tau or one of the sneutrinos is the LSP. We suggest four benchmark points with typical spectra and novel collider signatures which we investigate with a parton level Monte-Carlo simulation. We give an outlook for their detailed phenomenological analysis and simulation by the LHC collaborations, then including detector effects. In addition, we discuss a full Monte-Carlo simulation for single slepton production in association with a single top quark via an LQD type operator at the hadron colliders LHC and Tevatron. We present these results and show a predicted range of detectability for this process- for small couplings in various minimal supergravity models at the LHC. (orig.)
Minimal set of auxiliary fields and S-matrix for extended supergravity
Energy Technology Data Exchange (ETDEWEB)
Fradkin, E S; Vasiliev, M A [Physical Lebedev Institute - Moscow
1979-05-19
Minimal set of auxiliary fields for linearized SO(2) supergravity and one-parameter extension of the minimal auxiliary fields in the SO(1) supergravity are constructed. The expression for the S-matrix in SO(2) supergravity are given.
3D gauged supergravity from SU(2) reduction of $N=1$ 6D supergravity
Gava, Edi; Narain, K S
2010-01-01
We obtain Yang-Mills $SU(2)\\times G$ gauged supergravity in three dimensions from $SU(2)$ group manifold reduction of (1,0) six dimensional supergravity coupled to an anti-symmetric tensor multiplet and gauge vector multiplets in the adjoint of $G$. The reduced theory is consistently truncated to $N=4$ 3D supergravity coupled to $4(1+\\textrm{dim}\\, G)$ bosonic and $4(1+\\textrm{dim}\\, G)$ fermionic propagating degrees of freedom. This is in contrast to the reduction in which there are also massive vector fields. The scalar manifold is $\\mathbf{R}\\times \\frac{SO(3,\\, \\textrm{dim}\\, G)}{SO(3)\\times SO(\\textrm{dim}\\, G)}$, and there is a $SU(2)\\times G$ gauge group. We then construct $N=4$ Chern-Simons $(SO(3)\\ltimes \\mathbf{R}^3)\\times (G\\ltimes \\mathbf{R}^{\\textrm{dim}G})$ three dimensional gauged supergravity with scalar manifold $\\frac{SO(4,\\,1+\\textrm{dim}G)}{SO(4)\\times SO(1+\\textrm{dim}G)}$ and explicitly show that this theory is on-shell equivalent to the Yang-Mills $SO(3)\\times G$ gauged supergravity the...
Braneworld Inflation in Supergravity with a Shift Symmetric Kähler ...
Indian Academy of Sciences (India)
Recently, the supersymmetric hybrid model and its extensions have been proposed to assure the natural inflationary scenario (Lyth & Stewart 1996; Enqvist &. McDonald 1998; Clesse et al. 2014), since it provides an interesting possibility of occurring inflation in the grand unified theories (Civiletti et al. 2014), which pro-.
Testing predictions of the quantum landscape multiverse 2: the exponential inflationary potential
International Nuclear Information System (INIS)
Valentino, Eleonora Di; Mersini-Houghton, Laura
2017-01-01
The 2015 Planck data release tightened the region of the allowed inflationary models. Inflationary models with convex potentials have now been ruled out since they produce a large tensor to scalar ratio. Meanwhile the same data offers interesting hints on possible deviations from the standard picture of CMB perturbations. Here we revisit the predictions of the theory of the origin of the universe from the landscape multiverse for the case of exponential inflation, for two reasons: firstly to check the status of the anomalies associated with this theory, in the light of the recent Planck data; secondly, to search for a counterexample whereby new physics modifications may bring convex inflationary potentials, thought to have been ruled out, back into the region of potentials allowed by data. Using the exponential inflation as an example of convex potentials, we find that the answer to both tests is positive: modifications to the perturbation spectrum and to the Newtonian potential of the universe originating from the quantum entanglement, bring the exponential potential, back within the allowed region of current data; and, the series of anomalies previously predicted in this theory, is still in good agreement with current data. Hence our finding for this convex potential comes at the price of allowing for additional thermal relic particles, equivalently dark radiation, in the early universe.
Testing predictions of the quantum landscape multiverse 2: the exponential inflationary potential
Energy Technology Data Exchange (ETDEWEB)
Valentino, Eleonora Di [Institut d' Astrophysique de Paris (UMR7095: CNRS and UPMC-Sorbonne Universities), F-75014, Paris (France); Mersini-Houghton, Laura, E-mail: valentin@iap.fr, E-mail: mersini@physics.unc.edu [Department of Physics and Astronomy, UNC-Chapel Hill, Chapel Hill, NC 27599 (United States)
2017-03-01
The 2015 Planck data release tightened the region of the allowed inflationary models. Inflationary models with convex potentials have now been ruled out since they produce a large tensor to scalar ratio. Meanwhile the same data offers interesting hints on possible deviations from the standard picture of CMB perturbations. Here we revisit the predictions of the theory of the origin of the universe from the landscape multiverse for the case of exponential inflation, for two reasons: firstly to check the status of the anomalies associated with this theory, in the light of the recent Planck data; secondly, to search for a counterexample whereby new physics modifications may bring convex inflationary potentials, thought to have been ruled out, back into the region of potentials allowed by data. Using the exponential inflation as an example of convex potentials, we find that the answer to both tests is positive: modifications to the perturbation spectrum and to the Newtonian potential of the universe originating from the quantum entanglement, bring the exponential potential, back within the allowed region of current data; and, the series of anomalies previously predicted in this theory, is still in good agreement with current data. Hence our finding for this convex potential comes at the price of allowing for additional thermal relic particles, equivalently dark radiation, in the early universe.
Generalized supersymmetric cosmological term in N=1 supergravity
Energy Technology Data Exchange (ETDEWEB)
Concha, P.K.; Rodríguez, E.K. [Departamento de Física, Universidad de Concepción,Casilla 160-C, Concepción (Chile); Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino,Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Via Pietro Giuria 1, 10125 Torino (Italy); Salgado, P. [Departamento de Física, Universidad de Concepción,Casilla 160-C, Concepción (Chile)
2015-08-04
An alternative way of introducing the supersymmetric cosmological term in a supergravity theory is presented. We show that the AdS-Lorentz superalgebra allows to construct a geometrical formulation of supergravity containing a generalized supersymmetric cosmological constant. The N=1, D=4 supergravity action is built only from the curvatures of the AdS-Lorentz superalgebra and corresponds to a MacDowell-Mansouri like action. The extension to a generalized AdS-Lorentz superalgebra is also analyzed.
On the hidden maxwell superalgebra underlying D = 4 supergravity
Energy Technology Data Exchange (ETDEWEB)
Penafiel, D.M. [Departamento de Fisica, Universidad de Concepcion (Chile); DISAT, Politecnico di Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino (Italy); Ravera, L. [DISAT, Politecnico di Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino (Italy)
2017-09-15
In this work, we expand the hidden AdS-Lorentz superalgebra underlying D = 4 supergravity, reaching a (hidden) Maxwell superalgebra. The latter can be viewed as an extension involving cosmological constant of the superalgebra underlying D = 4 supergravity in flat spacetime. We write the Maurer-Cartan equations in this context and we find some interesting extensions of the antisymmetric 3-form A{sup (3)} appearing in the Free Differential Algebra in Minkowski space. The structure of Free Differential Algebras is obtained by considering the zero curvature equations. We write the parametrization of A{sup (3)} in terms of 1-forms and we rend the topological features of its extensions manifest. We interestingly find out that the structure of these extensions, and consequently the structure of the corresponding boundary contribution dA{sup (3)}, strongly depends on the form of the extra fermionic generator appearing in the hidden Maxwell superalgebra. The model we develop in this work is defined in an enlarged superspace with respect to the ordinary one, and the extra bosonic and fermionic 1-forms required for the closure of the hidden Maxwell superalgebra must be considered as physical fields in this enlarged superspace. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Supergravity and supersymmetry breaking in four and five dimensions
International Nuclear Information System (INIS)
Ellis, John; Lalak, Zygmunt; Pokorski, Stefan; Thomas, Steven
1999-01-01
We discuss supersymmetry breaking in the field-theoretical limit of the strongly coupled heterotic string compactified on a Calabi-Yau manifold, from the different perspectives of four and five dimensions. The former applies to light degrees of freedom below the threshold for five-dimensional Kaluza-Klein excitations, whereas the five-dimensional perspective is also valid up to the Calabi-Yau scale. We show how, in the latter case, two gauge sectors separated in the fifth dimension are combined to form a consistent four-dimensional supergravity. In the lowest order of the κ 2/3 expansion, we show how a four-dimensional supergravity with gauge kinetic function f 1,2 =S is reproduced, and we show how higher-order terms give rise to four-dimensional operators that differ in the two gauge sectors. In the four-dimensional approach, supersymmetry is seen to be broken when condensates form on one or both walls, and the goldstino may have a non-zero dilatino component. As in the five-dimensional approach, the Lagrangian is not a perfect square, and we have not identified a vacuum with broken supersymmetry and zero vacuum energy. We derive soft supersymmetry-breaking terms for non-standard perturbative embeddings, that are relevant in more general situations such as type I/type IIB orientifold models
Generalized Attractor Points in Gauged Supergravity
Energy Technology Data Exchange (ETDEWEB)
Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Kallosh, Renata; /Stanford U., Phys. Dept.; Shmakova, Marina; /KIPAC, Menlo Park /SLAC /Stanford U., Phys. Dept.
2011-08-15
The attractor mechanism governs the near-horizon geometry of extremal black holes in ungauged 4D N=2 supergravity theories and in Calabi-Yau compactifications of string theory. In this paper, we study a natural generalization of this mechanism to solutions of arbitrary 4D N=2 gauged supergravities. We define generalized attractor points as solutions of an ansatz which reduces the Einstein, gauge field, and scalar equations of motion to algebraic equations. The simplest generalized attractor geometries are characterized by non-vanishing constant anholonomy coefficients in an orthonormal frame. Basic examples include Lifshitz and Schroedinger solutions, as well as AdS and dS vacua. There is a generalized attractor potential whose critical points are the attractor points, and its extremization explains the algebraic nature of the equations governing both supersymmetric and non-supersymmetric attractors.
High energy scattering in gravity and supergravity
DEFF Research Database (Denmark)
B. Giddings, Steven; Schmidt-Sommerfeld, Maximilian; Andersen, Jeppe Rosenkrantz
2010-01-01
We investigate features of perturbative gravity and supergravity by studying scattering in the ultraplanckian limit, and sharpen arguments that the dynamics is governed by long-distance physics. A simple example capturing aspects of the eikonal resummation suggests why short distance phenomena...... and in particular divergences or nonrenormalizability do not necessarily play a central role in this regime. A more profound problem is apparently unitarity. These considerations can be illustrated by showing that known gravity and supergravity amplitudes have the same long-distance behavior, despite the extra...... a physical scattering process, and ultraplanckian scattering exhibiting Regge behavior. These arguments sharpen the need to find a nonperturbative completion of gravity with mechanisms which restore unitarity in the strong gravity regime....
HKT geometry and de Sitter supergravity
International Nuclear Information System (INIS)
Grover, Jai; Gutowski, Jan B.; Herdeiro, Carlos A.R.; Sabra, Wafic
2009-01-01
Solutions of five-dimensional minimal de Sitter supergravity admitting Killing spinors are considered. It is shown that the 'timelike' solutions are determined in terms of a four-dimensional hyper-Kaehler torsion (HKT) manifold. If the HKT manifold is conformally hyper-Kaehler the most general solution can be obtained from a sub-class of supersymmetric solutions of minimal N=2 ungauged supergravity, by means of a simple transformation. Examples include a multi-BMPV de Sitter solution, describing multiple rotating black holes co-moving with the expansion of the universe. If the HKT manifold is not conformally hyper-Kaehler, examples admitting a tri-holomorphic Killing vector field are constructed in terms of certain solutions of three-dimensional Einstein-Weyl geometry
A superstring field theory for supergravity
Reid-Edwards, R. A.; Riccombeni, D. A.
2017-09-01
A covariant closed superstring field theory, equivalent to classical tendimensional Type II supergravity, is presented. The defining conformal field theory is the ambitwistor string worldsheet theory of Mason and Skinner. This theory is known to reproduce the scattering amplitudes of Cachazo, He and Yuan in which the scattering equations play an important role and the string field theory naturally incorporates these results. We investigate the operator formalism description of the ambitwsitor string and propose an action for the string field theory of the bosonic and supersymmetric theories. The correct linearised gauge symmetries and spacetime actions are explicitly reproduced and evidence is given that the action is correct to all orders. The focus is on the NeveuSchwarz sector and the explicit description of tree level perturbation theory about flat spacetime. Application of the string field theory to general supergravity backgrounds and the inclusion of the Ramond sector are briefly discussed.
Scattering equations, supergravity integrands, and pure spinors
Energy Technology Data Exchange (ETDEWEB)
Adamo, Tim; Casali, Eduardo [Department of Applied Mathematics & Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)
2015-05-25
The tree-level S-matrix of type II supergravity can be computed in scattering equation form by correlators in a worldsheet theory analogous to a chiral, infinite tension limit of the pure spinor formalism. By defining a non-minimal version of this theory, we give a prescription for computing correlators on higher genus worldsheets which manifest space-time supersymmetry. These correlators are conjectured to provide the loop integrands of supergravity scattering amplitudes, supported on the scattering equations. We give non-trivial evidence in support of this conjecture at genus one and two with four external states. Throughout, we find a close correspondence with the pure spinor formalism of superstring theory, particularly regarding regulators and zero-mode counting.
Stable supergravity dual of nonsupersymmetric glue
International Nuclear Information System (INIS)
Babington, James; Crooks, David E.; Evans, Nick
2003-01-01
We study nonsupersymmetric fermion mass and condensate deformations of the AdS conformal field theory correspondence. The five dimensional supergravity flows are lifted to a complete and remarkably simple ten dimensional background. A brane probe analysis shows that when all the fermions have an equal mass a positive mass is generated for all six scalar fields leaving nonsupersymmetric Yang-Mills theory in the deep infrared. We numerically determine the potential, produced by the background, in the Schroedinger equation relevant to the study of O ++ glueballs. The potential is a bounded well, providing evidence of stability and for a discrete, confined spectrum. The geometry can also describe the supergravity background around an (unstable) fuzzy 5-brane
Scattering equations, supergravity integrands, and pure spinors
International Nuclear Information System (INIS)
Adamo, Tim; Casali, Eduardo
2015-01-01
The tree-level S-matrix of type II supergravity can be computed in scattering equation form by correlators in a worldsheet theory analogous to a chiral, infinite tension limit of the pure spinor formalism. By defining a non-minimal version of this theory, we give a prescription for computing correlators on higher genus worldsheets which manifest space-time supersymmetry. These correlators are conjectured to provide the loop integrands of supergravity scattering amplitudes, supported on the scattering equations. We give non-trivial evidence in support of this conjecture at genus one and two with four external states. Throughout, we find a close correspondence with the pure spinor formalism of superstring theory, particularly regarding regulators and zero-mode counting.
Tensor calculus for supergravity on a manifold with boundary
International Nuclear Information System (INIS)
Belyaev, Dmitry V.; Nieuwenhuizen, Peter van
2008-01-01
Using the simple setting of 3D N = 1 supergravity, we show how the tensor calculus of supergravity can be extended to manifolds with boundary. We present an extension of the standard F-density formula which yields supersymmetric bulk-plus-boundary actions. To construct additional separately supersymmetric boundary actions, we decompose bulk supergravity and bulk matter multiplets into co-dimension one submultiplets. As an illustration we obtain the supersymmetric extension of the York-Gibbons-Hawking extrinsic curvature boundary term. We emphasize that our construction does not require any boundary conditions on off-shell fields. This gives a significant improvement over the existing orbifold supergravity tensor calculus
One-loop infinities in dimensionally reduced supergravities
International Nuclear Information System (INIS)
Fradkin, E.S.; Tseytlin, A.A.
1983-11-01
It is proved explicitly in the paper that d=4 theory following via reduction from N=1, d=10 supergravities is not finite at one loop while the version of N=8 supergravity directly following from N=1, d=11 theory is one-loop finite. The method used is based on quantization of initial higher dimensional theory as a first step. The results also suggest possible existence of non-standard (higher N) d>4 supergravities which reduce to d=4 theories with finite N=8 supergravity sector. (author)
On the construction of supergravity theories
International Nuclear Information System (INIS)
Holten, J.W. van.
1980-01-01
A precise and technical definition of supersymmetry is given. The theory of SO(2) supergravity is presented. The linearized version of the full multiplet, including auxiliary fields, of this theory as well as of certain matter multiplets, are constructed. These results are extended to all orders in the coupling constant kappa. Finally, the quantization procedure for theories with local gauge invariance and its generalization for theories with non-closing, or open, gauge algebras is presented. (Auth.)
Ultraviolet Behavior of N = 8 Supergravity
International Nuclear Information System (INIS)
Dixon, Lance J.
2010-01-01
In these lectures the author describes the remarkable ultraviolet behavior of N = 8 supergravity, which through four loops is no worse than that of N = 4 super-Yang-Mills theory (a finite theory). I also explain the computational tools that allow multi-loop amplitudes to be evaluated in this theory - the KLT relations and the unitarity method - and sketch how ultraviolet divergences are extracted from the amplitudes.
Newton-Cartan supergravity with torsion and Schrödinger supergravity
International Nuclear Information System (INIS)
Bergshoeff, Eric; Rosseel, Jan; Zojer, Thomas
2015-01-01
We derive a torsionfull version of three-dimensional N=2 Newton-Cartan supergravity using a non-relativistic notion of the superconformal tensor calculus. The “superconformal” theory that we start with is Schrödinger supergravity which we obtain by gauging the Schrödinger superalgebra. We present two non-relativistic N=2 matter multiplets that can be used as compensators in the superconformal calculus. They lead to two different off-shell formulations which, in analogy with the relativistic case, we call “old minimal” and “new minimal” Newton-Cartan supergravity. We find similarities but also point out some differences with respect to the relativistic case.
Newton-Cartan supergravity with torsion and Schrödinger supergravity
Energy Technology Data Exchange (ETDEWEB)
Bergshoeff, Eric [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Rosseel, Jan [Institute for Theoretical Physics, Vienna University of Technology,Wiedner Hauptstr. 8-10/136, A-1040 Vienna (Austria); Albert Einstein Center for Fundamental Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); Zojer, Thomas [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands)
2015-11-25
We derive a torsionfull version of three-dimensional N=2 Newton-Cartan supergravity using a non-relativistic notion of the superconformal tensor calculus. The “superconformal” theory that we start with is Schrödinger supergravity which we obtain by gauging the Schrödinger superalgebra. We present two non-relativistic N=2 matter multiplets that can be used as compensators in the superconformal calculus. They lead to two different off-shell formulations which, in analogy with the relativistic case, we call “old minimal” and “new minimal” Newton-Cartan supergravity. We find similarities but also point out some differences with respect to the relativistic case.
Implications of Planck2015 for inflationary, ekpyrotic and anamorphic bouncing cosmologies
Ijjas, Anna; Steinhardt, Paul J.
2016-02-01
The results from Planck2015, when combined with earlier observations from the Wilkinson Microwave Anisotropy Probe, Atacama Cosmology Telescope, South Pole Telescope and other experiments, were the first observations to disfavor the ‘classic’ inflationary paradigm. To satisfy the observational constraints, inflationary theorists have been forced to consider plateau-like inflaton potentials that introduce more parameters and more fine-tuning, problematic initial conditions, multiverse-unpredictability issues, and a new ‘unlikeliness problem’. Some propose turning instead to a ‘postmodern’ inflationary paradigm in which the cosmological properties in our observable Universe are only locally valid and set randomly, with completely different properties (and perhaps even different physical laws) existing in most regions outside our horizon. By contrast, the new results are consistent with the simplest versions of ekpyrotic cyclic models in which the Universe is smoothed and flattened during a period of slow contraction followed by a bounce, and another promising bouncing theory, anamorphic cosmology, has been proposed that can produce distinctive predictions.
Implications of Planck2015 for inflationary, ekpyrotic and anamorphic bouncing cosmologies
International Nuclear Information System (INIS)
Ijjas, Anna; Steinhardt, Paul J
2016-01-01
The results from Planck2015, when combined with earlier observations from the Wilkinson Microwave Anisotropy Probe, Atacama Cosmology Telescope, South Pole Telescope and other experiments, were the first observations to disfavor the ‘classic’ inflationary paradigm. To satisfy the observational constraints, inflationary theorists have been forced to consider plateau-like inflaton potentials that introduce more parameters and more fine-tuning, problematic initial conditions, multiverse-unpredictability issues, and a new ‘unlikeliness problem’. Some propose turning instead to a ‘postmodern’ inflationary paradigm in which the cosmological properties in our observable Universe are only locally valid and set randomly, with completely different properties (and perhaps even different physical laws) existing in most regions outside our horizon. By contrast, the new results are consistent with the simplest versions of ekpyrotic cyclic models in which the Universe is smoothed and flattened during a period of slow contraction followed by a bounce, and another promising bouncing theory, anamorphic cosmology, has been proposed that can produce distinctive predictions. (paper)
Guarino, Adolfo
2018-03-01
Supersymmetric {AdS}4, {AdS}2 × Σ 2 and asymptotically AdS4 black hole solutions are studied in the context of non-minimal N=2 supergravity models involving three vector multiplets (STU-model) and Abelian gaugings of the universal hypermultiplet moduli space. Such models correspond to consistent subsectors of the {SO}(p,q) and {ISO}(p,q) gauged maximal supergravities that arise from the reduction of 11D and massive IIA supergravity on {H}^{(p,q)} spaces down to four dimensions. A unified description of all the models is provided in terms of a square-root prepotential and the gauging of a duality-hidden symmetry pair of the universal hypermultiplet. Some aspects of M-theory and massive IIA holography are mentioned in passing.
Bayesian evidence and predictivity of the inflationary paradigm
Energy Technology Data Exchange (ETDEWEB)
Gubitosi, Giulia; Lagos, Macarena; Magueijo, João [Theoretical Physics, Blackett Laboratory, Imperial College, London, SW7 2BZ (United Kingdom); Allison, Rupert, E-mail: g.gubitosi@imperial.ac.uk, E-mail: m.lagos13@imperial.ac.uk, E-mail: j.magueijo@imperial.ac.uk, E-mail: rupert.allison@astro.ox.ac.uk [Astrophysics, University of Oxford, DWB, Keble Road, Oxford OX1 3RH (United Kingdom)
2016-06-01
In this paper we consider the issue of paradigm evaluation by applying Bayes' theorem along the following nested hierarchy of progressively more complex structures: i) parameter estimation (within a model), ii) model selection and comparison (within a paradigm), iii) paradigm evaluation. In such a hierarchy the Bayesian evidence works both as the posterior's normalization at a given level and as the likelihood function at the next level up. Whilst raising no objections to the standard application of the procedure at the two lowest levels, we argue that it should receive a considerable modification when evaluating paradigms, when testability and fitting data are equally important. By considering toy models we illustrate how models and paradigms that are difficult to falsify are always favoured by the Bayes factor. We argue that the evidence for a paradigm should not only be high for a given dataset, but exceptional with respect to what it would have been, had the data been different. With this motivation we propose a measure which we term predictivity , as well as a prior to be incorporated into the Bayesian framework, penalising unpredictivity as much as not fitting data. We apply this measure to inflation seen as a whole, and to a scenario where a specific inflationary model is hypothetically deemed as the only one viable as a result of information alien to cosmology (e.g. Solar System gravity experiments, or particle physics input). We conclude that cosmic inflation is currently hard to falsify, but that this could change were external/additional information to cosmology to select one of its many models. We also compare this state of affairs to bimetric varying speed of light cosmology.
International Nuclear Information System (INIS)
Saririan, K.
1997-05-01
In this thesis, the author presents some works in the direction of studying quantum effects in locally supersymmetric effective field theories that appear in the low energy limit of superstring theory. After reviewing the Kaehler covariant formulation of supergravity, he shows the calculation of the divergent one-loop contribution to the effective boson Lagrangian for supergravity, including the Yang-Mills sector and the helicity-odd operators that arise from integration over fermion fields. The only restriction is on the Yang-Mills kinetic energy normalization function, which is taken diagonal in gauge indices, as in models obtained from superstrings. He then presents the full result for the divergent one-loop contribution to the effective boson Lagrangian for supergravity coupled to chiral and Yang-Mills supermultiplets. He also considers the specific case of dilaton couplings in effective supergravity Lagrangians from superstrings, for which the one-loop result is considerably simplified. He studies gaugino condensation in the presence of an intermediate mass scale in the hidden sector. S-duality is imposed as an approximate symmetry of the effective supergravity theory. Furthermore, the author includes in the Kaehler potential the renormalization of the gauge coupling and the one-loop threshold corrections at the intermediate scale. It is shown that confinement is indeed achieved. Furthermore, a new running behavior of the dilaton arises which he attributes to S-duality. He also discusses the effects of the intermediate scale, and possible phenomenological implications of this model
Compactifications of IIA supergravity on SU(2)-structure manifolds
Energy Technology Data Exchange (ETDEWEB)
Spanjaard, B.
2008-07-15
In this thesis, we study compactifications of type IIA supergravity on six-dimensional manifolds with an SU(2)-structure. A general study of six-dimensional manifolds with SU(2)-structure shows that IIA supergravity compactified on such a manifold should yield a four-dimensional gauged N=4 supergravity. We explicitly derive the bosonic spectrum, gauge transformations and action for IIA supergravity compactified on two different manifolds with SU(2)-structure, one of which also has an H{sup (3)}{sub 10}-flux, and confirm that the resulting four-dimensional theories are indeed N=4 gauged supergravities. In the second chapter, we study an explicit construction of a set of SU(2)-structure manifolds. This construction involves a Scherk-Schwarz duality twist reduction of the half-maximal six-dimensional supergravity obtained by compactifying IIA supergravity on a K3. This reduction results in a gauged N=4 four-dimensional supergravity, where the gaugings can be divided into three classes of parameters. We relate two of the classes to parameters we found before, and argue that the third class of parameters could be interpreted as a mirror flux. (orig.)
N=1 supergravity off-shell in six dimensions
International Nuclear Information System (INIS)
Smith, A.W.
1983-01-01
It is shown that the N=1 supergravity in six dimensions showns useful characteristics to study the unification of a gauge theory together with the supergravity, via dimensinal reduction, giving a geometrical interpretation for the internal quantum numbers in the reduced theory. (L.C.) [pt
Construction of the superalgebras for N=1 supergravity
International Nuclear Information System (INIS)
Ivanov, E.A.; Niederle, J.
1984-11-01
It is shown that the infinite parameter gauge superalgebras of the conformal and of the N=1 Einstein supergravities can be obtained as the closures of various two finite-parameter superalgebras. In the conformal case the standard, minimal and Einsteinian closures are studied. In the case of the N=1 Einstein supergravities the minimal and non-minimal closures are discussed. (author)
Attractor horizons in six-dimensional type IIB supergravity
Energy Technology Data Exchange (ETDEWEB)
Astefanesei, Dumitru, E-mail: dumitru.astefanesei@ucv.cl [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4059, Valparaiso (Chile); Miskovic, Olivera, E-mail: olivera.miskovic@ucv.cl [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4059, Valparaiso (Chile); Olea, Rodrigo, E-mail: rodrigo.olea@unab.cl [Universidad Andres Bello, Departamento de Ciencias Fisicas, Republica 220, Santiago (Chile)
2012-08-14
We consider near horizon geometries of extremal black holes in six-dimensional type IIB supergravity. In particular, we use the entropy function formalism to compute the charges and thermodynamic entropy of these solutions. We also comment on the role of attractor mechanism in understanding the entropy of the Hopf T-dual solutions in type IIA supergravity.
Ambitwistor pure spinor string in a type II supergravity background
Energy Technology Data Exchange (ETDEWEB)
Chandia, Osvaldo [Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Diagonal Las Torres 2640, Peñalolén, Santiago (Chile); Vallilo, Brenno Carlini [Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andres Bello,República 220, Santiago (Chile)
2015-06-30
We construct the ambitwistor pure spinor string in a general type II supergravity background in the semi-classical regime. Almost all supergravity constraints are obtained from nilpotency of the BRST charge and further consistency conditions from additional world-sheet the case of AdS{sub 5}×S{sup 5} background.
The Bianchi classification of maximal D = 8 gauged supergravities
Bergshoeff, Eric; Gran, Ulf; Linares, Román; Nielsen, Mikkel; Ortín, Tomás; Roest, Diederik
2003-01-01
We perform the generalized dimensional reduction of D = 11 supergravity over three-dimensional group manifolds as classified by Bianchi. Thus, we construct 11 different maximal D = 8 gauged supergravities, two of which have an additional parameter. One class of group manifolds (class B) leads to
The Bianchi classification of maximal D=8 gauged supergravities
Bergshoeff, E; Gran, U; Linares, R; Nielsen, M; Ortin, T; Roest, D
2003-01-01
We perform the generalized dimensional reduction of D = 11 supergravity over three-dimensional group manifolds as classified by Bianchi. Thus, we construct 11 different maximal D = 8 gauged supergravities, two of which have an additional parameter. One class of group manifolds (class B) leads to
Invisible axion in the hidden sector of no-scale supergravity
International Nuclear Information System (INIS)
Sato, Hikaru
1987-01-01
We propose a new axion model which incorporates the U(1) PQ symmetry into a hidden sector, as well as an observable sector, of no-scale supergravity models. The axion is a spin-zero field in the hidden sector. The U(1) PQ symmetry is naturally embedded in the family symmetry of the no-scale models. Invisible axions live in the gravity hidden sector without conflict with the cosmological and astrophysical constraints. (orig.)
The no-hair conjecture in 2D dilaton supergravity
International Nuclear Information System (INIS)
Gamboa, J.; Georgelin, Y.
1993-06-01
Two dimensional dilaton gravity and supergravity are studied following Hamiltonian methods. The structure of constraints of 2D dilaton gravity and the 2D dilaton supergravity theory is discussed taking the square root of the bosonic constraints. The equations of motion are integrated in both cases, and it is shown that the solutions of the equation of motion of 2D dilaton supergravity differs from the solutions of 2D dilaton gravity only by boundary conditions on the fermionic variables, i.e. the black holes of 2D dilaton supergravity theory are exactly the same black holes of 2D bosonic dilaton gravity modulo supersymmetry transformations. This result is the bidimensional analogue of the no-hair theorem for supergravity. (authors). 28 refs
Residual supersymmetry of compactified d = 10 supergravity
International Nuclear Information System (INIS)
Wit, B. de; Smit, D.J.; Hari Dass, N.D.
1986-05-01
The conditions for residual supersymmetry in compactified ten-dimensional supergravity theories are investigated, including the effect of a non-constant 'warp factor'. The analysis is based on on-shell transformation laws which implies that certain linear combinations of classical field equations must be satisfied. The conditions for superysymmetry are, in general, not very restrictive. When, in addition, one assumes the validity of Bianchi identities, two independent contractions of the Einstein equation are implied. These equations exclude d=4 de Sitter space; for compactifications to d=4 Minkowski space they only allow purely metric Ricci-flat field configurations with constant warp factor. (Auth.)
The simplest group of Einstein supergravity
International Nuclear Information System (INIS)
Ogievetsky, V.I.; Sokatchev, E.S.
1979-01-01
The simplest supergroup of Einstein supergravity is considered. It is the complex supergroup of general coordinate transformations in left- and right-handed chiral conjugated superspaces restricted by the condition of left- and right- supervolume-preservation. The real part of the vector coordinate of the superspace is identified with the space-time coordinate xsup(m) and the imaginary one, with the axial gravitational superfield Hsup(m) (x, theta, anti theta). The transformations of the field components of Hsup(m) are studied in detail. The approach described is the geometrical basis of the so-called ''tensor calculus''
Nonlinear symmetries of black hole entropy in gauged supergravity
Energy Technology Data Exchange (ETDEWEB)
Klemm, Dietmar [Dipartimento di Fisica, Università di Milano,and INFN, Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy); Marrani, Alessio [Museo Storico della Fisica e Centro Studi e Ricerche ‘Enrico Fermi’,Via Panisperna 89A, I-00184 Roma (Italy); Dipartimento di Fisica e Astronomia ‘Galileo Galilei’, Università di Padova,and INFN, Sezione di Padova,Via Marzolo 8, I-35131 Padova (Italy); Petri, Nicolò; Rabbiosi, Marco [Dipartimento di Fisica, Università di Milano,and INFN, Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy)
2017-04-04
Freudenthal duality in N=2, D=4 ungauged supergravity is generated by an anti-involutive operator that acts on the electromagnetic fluxes, and results to be a symmetry of the Bekenstein-Hawking entropy. We show that, with a suitable extension, this duality can be generalized to the abelian gauged case as well, even in presence of hypermultiplets. By defining Freudenthal duality along the scalar flow, one can prove that two configurations of charges and gaugings linked by the Freudenthal operator share the same set of values of the scalar fields at the black hole horizon. Consequently, Freudenthal duality is promoted to a nonlinear symmetry of the black hole entropy. We explicitly show this invariance for the model with prepotential F=−iX{sup 0}X{sup 1} and Fayet-Iliopoulos gauging.
Chern-Simons supergravity plus matter near the boundary of AdS3
International Nuclear Information System (INIS)
Deger, N.S.; Kaya, A.; Sezgin, E.; Sundell, P.; Tanii, Y.
2001-01-01
We examine the boundary behaviour of the gauged N=(2,0) supergravity in D=3 coupled to an arbitrary number of scalar supermultiplets which parametrize a Kaehler manifold. In addition to the gravitational coupling constant, the model depends on two parameters, namely the cosmological constant and the size of the Kaehler manifold. It is shown that regular and irregular boundary conditions can be imposed on the matter fields depending on the size of the sigma model manifold. It is also shown that the super AdS transformations in the bulk produce the transformations of the N=(2,0) conformal supergravity and scalar multiplets on the boundary, containing fields with nonvanishing Weyl weights determined by the ratio of the sigma model and the gravitational coupling constants. Various types of (2,0) superconformal multiplets are found on the boundary and in one case the superconformal symmetry is shown to be realized in an unconventional way
New gauged N = 8, D = 4 supergravities
International Nuclear Information System (INIS)
Hull, C M
2003-01-01
New gaugings of four-dimensional N = 8 supergravity are constructed, including one which has a Minkowski space vacuum that preserves N = 2 supersymmetry and in which the gauge group is broken to SU(3) x U(1) 2 . Previous gaugings used the form of the ungauged action which is invariant under a rigid SL (8,R) symmetry and promoted a 28-dimensional subgroup (SO(8), SO(p, 8 - p) or the non-semi-simple contraction CSO(p, q, 8 - p - q)) to a local gauge group. Here, a dual form of the ungauged action is used which is invariant under SU*(8) instead of SL (8,R) and new theories are obtained by gauging 28-dimensional subgroups of SU*(8). The gauge groups are non-semi-simple and are different real forms of the CSO(2p, 8 - 2p) groups, denoted as CSO*(2p, 8 - 2p), and the new theories have a rigid SU(2) symmetry. The five-dimensional gauged N = 8 supergravities are dimensionally reduced to D = 4. The D = 5, SO(p, 6 - p) gauge theories reduce, after a duality transformation, to the D = 4, CSO(p, 6 - p, 2) gauging while the SO*(6) gauge theory reduces to the D = 4, CSO*(6, 2) gauge theory. The new theories are related to the old ones via an analytic continuation. The non-semi-simple gaugings can be dualized to forms with different gauge groups
Vacua of maximal gauged D=3 supergravities
International Nuclear Information System (INIS)
Fischbacher, T; Nicolai, H; Samtleben, H
2002-01-01
We analyse the scalar potentials of maximal gauged three-dimensional supergravities which reveal a surprisingly rich structure. In contrast to maximal supergravities in dimensions D≥4, all these theories possess a maximally supersymmetric (N=16) ground state with negative cosmological constant Λ 2 gauged theory, whose maximally supersymmetric groundstate has Λ = 0. We compute the mass spectra of bosonic and fermionic fluctuations around these vacua and identify the unitary irreducible representations of the relevant background (super)isometry groups to which they belong. In addition, we find several stationary points which are not maximally supersymmetric, and determine their complete mass spectra as well. In particular, we show that there are analogues of all stationary points found in higher dimensions, among them are de Sitter (dS) vacua in the theories with noncompact gauge groups SO(5, 3) 2 and SO(4, 4) 2 , as well as anti-de Sitter (AdS) vacua in the compact gauged theory preserving 1/4 and 1/8 of the supersymmetries. All the dS vacua have tachyonic instabilities, whereas there do exist nonsupersymmetric AdS vacua which are stable, again in contrast to the D≥4 theories
Gauged supergravities from M-theory reductions
Katmadas, Stefanos; Tomasiello, Alessandro
2018-04-01
In supergravity compactifications, there is in general no clear prescription on how to select a finite-dimensional family of metrics on the internal space, and a family of forms on which to expand the various potentials, such that the lower-dimensional effective theory is supersymmetric. We propose a finite-dimensional family of deformations for regular Sasaki-Einstein seven-manifolds M 7, relevant for M-theory compactifications down to four dimensions. It consists of integrable Cauchy-Riemann structures, corresponding to complex deformations of the Calabi-Yau cone M 8 over M 7. The non-harmonic forms we propose are the ones contained in one of the Kohn-Rossi cohomology groups, which is finite-dimensional and naturally controls the deformations of Cauchy-Riemann structures. The same family of deformations can be also described in terms of twisted cohomology of the base M 6, or in terms of Milnor cycles arising in deformations of M 8. Using existing results on SU(3) structure compactifications, we briefly discuss the reduction of M-theory on our class of deformed Sasaki-Einstein manifolds to four-dimensional gauged supergravity.
Ward identities of local supersymmetry and spontaneous breaking of extended supergravity
International Nuclear Information System (INIS)
Cecotti, S.; Girardello, L.; Porrati, M.
1985-01-01
It is a general agreement that any extended supergravity theory, in order to lead to a viable model with acceptable phenomenological implications, should admit spontaneous breaking to N = 1 local supersymmetry in a Minkowski background. It is then important to understand the possible patterns of partial breaking of extended local supersymmetry. These patterns strongly depend on the theory being formulated directly in 4-D or in higher-D. In general, the higher-D theories lead to partial breaking in 4-D anti-de Sitter spaces. Examples are known with partial breaking in flat space. They result respectively from a generalized dimensional reduction of the N = 1 theory in 11-D or from the spontaneous compactification of the 10-D low-energy theory from the superstring theory and of a 6-D Maxwell-Einstein supergravity model. We will comment later on this example. In this paper we will discuss some considerations which apply to theories formulated in 4-D
Towards a worldsheet description of N=8 supergravity
International Nuclear Information System (INIS)
Lipstein, Arthur; Schomerus, Volker
2015-10-01
In this note we address the worldsheet description of 4-dimensional N=8 supergravity using ambitwistors. After gauging an appropriate current algebra, we argue that the only physical vertex operators correspond to the N=8 supermultiplet. It has previously been shown that worldsheet correlators give rise to supergravity tree level scattering amplitudes. We extend this work by proposing a definition for genus-one amplitudes that passes several consistency checks such as exhibiting modular invariance and reproducing the expected infrared behavior of 1-loop supergravity amplitudes.
Invariants for minimal conformal supergravity in six dimensions
Energy Technology Data Exchange (ETDEWEB)
Butter, Daniel [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Novak, Joseph; Theisen, Stefan [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Golm (Germany)
2016-12-15
We develop a new off-shell formulation for six-dimensional conformal supergravity obtained by gauging the 6D N=(1,0) superconformal algebra in superspace. This formulation is employed to construct two invariants for 6D N=(1,0) conformal supergravity, which contain C{sup 3} and C◻C terms at the component level. Using a conformal supercurrent analysis, we prove that these exhaust all such invariants in minimal conformal supergravity. Finally, we show how to construct the supersymmetric F◻F invariant in curved superspace.
Thermal gravitational-wave background in the general pre-inflationary scenario
Energy Technology Data Exchange (ETDEWEB)
Wang, Kai; Santos, Larissa; Zhao, Wen [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China); Xia, Jun-Qing, E-mail: ljwk@mail.ustc.edu.cn, E-mail: larissa@ustc.edu.cn, E-mail: xiajq@bnu.edu.cn, E-mail: wzhao7@ustc.edu.cn [Department of Astronomy, Beijing Normal University, Beijing 100875 (China)
2017-01-01
We investigate the primordial gravitational waves (PGWs) in the general scenario where the inflation is preceded by a pre-inflationary stage with the effective equation of state w . Comparing with the results in the usual inflationary models, the power spectrum of PGWs is modified in two aspects: one is the mixture of the perturbation modes caused by he presence of the pre-inflationary period, and the other is the thermal initial state formed at the Planck era of the early Universe. By investigating the observational imprints of these modifications on the B-mode polarization of cosmic microwave background (CMB) radiation, we obtain the constraints on the conformal temperature of the thermal gravitational-wave background T <5.01× 10{sup −4} Mpc{sup −1} and a tensor-to-scalar ratio r <0.084 (95% confident level), which follows the bounds on total number of e-folds N >63.5 for the model with w =1/3, and N >65.7 for that with w =1. By taking into account various noises and the foreground radiations, we forecast the detection possibility of the thermal gravitational-wave background by the future CMBPol mission, and find that if r >0.01, the detection is possible as long as T >1.5× 10{sup −4} Mpc{sup −1}. However, the effect of different w is quite small, and it seems impossible to determine its value from the potential observations of CMBPol mission.
Motivations for AdS/QCD from 10D supergravity solutions
International Nuclear Information System (INIS)
De Paula, Wayne
2016-01-01
We discuss some attempts for the construction of gravity duals of QCD-like theories. It is analysed some properties of solutions of 10D Type IIB supergravity theory that attempt to be dual to N= 1 gauge theories, in particular the solutions that belong to Papadoulos-Tseytlin ansatz. We argue that one could obtain 5D effective theories from 10d solutions and it motivates the use of phenomenological AdS/QCD models. (paper)
Observations on BI from N=2 supergravity and the general Ward identity
Energy Technology Data Exchange (ETDEWEB)
Andrianopoli, Laura [DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Torino (Italy); Concha, Patrick [DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Torino (Italy); Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción (Chile); D’Auria, Riccardo [DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Torino (Italy); Rodriguez, Evelyn [DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Torino (Italy); Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Trigiante, Mario [DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Torino (Italy)
2015-11-09
The multi-vector generalization of a rigid, partially-broken N=2 supersymmetric theory is presented as a rigid limit of a suitable gauged N=2 supergravity with electric, magnetic charges and antisymmetric tensor fields. This on the one hand generalizes a known result by Ferrara, Girardello and Porrati while on the other hand allows to recover the multi-vector BI models of http://dx.doi.org/10.1007/JHEP12(2014)065 from N=2 supergravity as the end-point of a hierarchical limit in which the Planck mass first and then the supersymmetry breaking scale are sent to infinity. We define, in the parent supergravity model, a new symplectic frame in which, in the rigid limit, manifest symplectic invariance is preserved and the electric and magnetic Fayet-Iliopoulos terms are fully originated from the dyonic components of the embedding tensor. The supergravity origin of several features of the resulting rigid supersymmetric theory are then elucidated, such as the presence of a traceless SU(2)- Lie algebra term in the Ward identity and the existence of a central charge in the supersymmetry algebra which manifests itself as a harmless gauge transformation on the gauge vectors of the rigid theory; we show that this effect can be interpreted as a kind of “superspace non-locality” which does not affect the rigid theory on space-time. To set the stage of our analysis we take the opportunity in this paper to provide and prove the relevant identities of the most general dyonic gauging of Special-Kaehler and Quaternionic-Kaehler isometries in a generic N=2 model, which include the supersymmetry Ward identity, in a fully symplectic-covariant formalism.
Energy Technology Data Exchange (ETDEWEB)
Jawad, Abdul; Rani, Shamaila [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Hussain, Shahzad [Aspire College, Department of Mathematics, Hafizabad (Pakistan); Videla, Nelson [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile)
2017-10-15
The warm inflation scenario in view of the modified Chaplygin gas is studied. We consider the inflationary expansion to be driven by a standard scalar field whose decay ratio Γ has a generic power-law dependence with the scalar field φ and the temperature of the thermal bath T. By assuming an exponential power-law dependence in the cosmic time for the scale factor a(t), corresponding to the intermediate inflation model, we solve the background and perturbative dynamics considering our model to evolve according to (1) weak dissipative regime and (2) strong dissipative regime. Specifically, we find explicit expressions for the dissipative coefficient, scalar potential, and the relevant inflationary observables like the scalar power spectrum, scalar spectral index, and tensor-to-scalar ratio. The free parameters characterizing our model are constrained by considering the essential condition for warm inflation, the conditions for the model evolves according to weak or strong dissipative regime, and the 2015 Planck results through the n{sub s}-r plane. (orig.)
The goldstino brane, the constrained superfields and matter in N=1 supergravity
International Nuclear Information System (INIS)
Bandos, Igor; Heller, Markus; Kuzenko, Sergei M.; Martucci, Luca; Sorokin, Dmitri
2016-01-01
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.
International Nuclear Information System (INIS)
Giedt, Joel
2003-01-01
We compute the component field four-dimensional N = 1 supergravity Lagrangian that is obtained from a superfield Lagrangian in the U(1) K formalism with a linear dilaton multiplet. All fermionic terms are presented. In a variety of important ways, our results generalize those that have been reported previously, and are flexible enough to accommodate many situations of phenomenological interest in string-inspired effective supergravity, especially models based on orbifold compactifications of the weakly coupled heterotic string. We provide for an effective theory of hidden gaugino and matter condensation. We include supersymmetric Green-Schwarz counterterms associated with the cancellation of U(1) and modular duality anomalies; the modular duality counterterm is of a rather general form. Our assumed form for the dilaton Kaehler potential is quite general and can accommodate Kaehler stabilization methods. We note possible applications of our results. We also discuss the usefulness of the linear dilaton formulation as a complement to the chiral dilaton approach
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.
Inoenue-Wigner contraction and D = 2 + 1 supergravity
Energy Technology Data Exchange (ETDEWEB)
Concha, P.K.; Rodriguez, E.K. [Universidad Adolfo Ibanez, Departamento de Ciencias, Facultad de Artes Liberales, Vina del Mar (Chile); Universidad Austral de Chile, Instituto de Ciencias Fisicas y Matematicas, Valdivia (Chile); Fierro, O. [Universidad Catolica de la Santisima Concepcion, Departamento de Matematica y Fisica Aplicadas, Concepcion (Chile)
2017-01-15
We present a generalization of the standard Inoenue-Wigner contraction by rescaling not only the generators of a Lie superalgebra but also the arbitrary constants appearing in the components of the invariant tensor. The procedure presented here allows one to obtain explicitly the Chern-Simons supergravity action of a contracted superalgebra. In particular we show that the Poincare limit can be performed to a D = 2 + 1 (p,q) AdS Chern-Simons supergravity in presence of the exotic form. We also construct a new three-dimensional (2,0) Maxwell Chern-Simons supergravity theory as a particular limit of (2,0) AdS-Lorentz supergravity theory. The generalization for N = p + q gravitinos is also considered. (orig.)
New set of auxiliary fields for supergravity theories
International Nuclear Information System (INIS)
Oliveira Rivelles, V. de.
1983-02-01
A brief introduction on supersymmetry is given. The problems with the obtainment of the auxiliary fields in supergravity theories are discussed, after a short presentation of the supersymmetry algebra representations. (L.C.) [pt
Tensor calculus for the vector multiplet coupled to supergravity
International Nuclear Information System (INIS)
Stelle, K.S.
1978-01-01
An invariant coupling of a local vector multiplet to supergravity is constructed in analogy with the D term invariant of global supersymmetry. The rules for combining local vector and chiral scalar multiplets of opposite chirality are given. (Auth.)
N=2 supergravity in superspace and the BRS symmetry
International Nuclear Information System (INIS)
Kachkachi, M.; Lhallabi, T.
1989-07-01
The quantum N = 2 Einstein supergravity action is constructed by requiring the BRS symmetry. This latter is derived by the use of the distorted horizontality conditions in the curved N = 2 harmonic superspace. (author). 16 refs
Maximal supergravities and the E10 model
International Nuclear Information System (INIS)
Kleinschmidt, Axel; Nicolai, Hermann
2006-01-01
The maximal rank hyperbolic Kac-Moody algebra e 10 has been conjectured to play a prominent role in the unification of duality symmetries in string and M theory. We review some recent developments supporting this conjecture
Critical N = (1, 1) general massive supergravity
Deger, Nihat Sadik; Moutsopoulos, George; Rosseel, Jan
2018-04-01
In this paper we study the supermultiplet structure of N = (1, 1) General Massive Supergravity at non-critical and critical points of its parameter space. To do this, we first linearize the theory around its maximally supersymmetric AdS3 vacuum and obtain the full linearized Lagrangian including fermionic terms. At generic values, linearized modes can be organized as two massless and 2 massive multiplets where supersymmetry relates them in the standard way. At critical points logarithmic modes appear and we find that in three of such points some of the supersymmetry transformations are non-invertible in logarithmic multiplets. However, in the fourth critical point, there is a massive logarithmic multiplet with invertible supersymmetry transformations.
Gauged N=8 supergravity in five dimensions
International Nuclear Information System (INIS)
Guenaydin, M.; Romans, L.J.; Warner, N.P.
1985-01-01
We construct gauged N=8 supergravity theories in five dimensions. Instead of the twenty-seven vector fields of the ungauged theory, the gauged theories contain fifteen vector fields and twelve second-rank antisymmetric tensor fields satisfying self-dual field equations. The fifteen vector fields can be used to gauge any of the fifteen-dimensional semisimple subgroups of SL(6, R), sepcifically SO(p, 6-p) for p=0, 1, 2, 3. The gauged theories also have a physical global SU(1,1) symmetry which survives from the Esub(6(6)) symmetry of the ungauged theory. This SU(1, 1) for the SO(6) gauging is presumably related to that of the chiral N=2 theory in ten dimensions. In our formalism we maintain a composite local USp(8) symmetry analogous to SU(8) in four dimensions. (orig.)
(Super-)Gravities of a different sort
International Nuclear Information System (INIS)
Edelstein, Jose D; Zanelli, Jorge
2006-01-01
We review the often forgotten fact that gravitation theories invariant under local de Sitter, anti-de Sitter or Poincare transformations can be constructed in all odd dimensions. These theories belong to the Chern-Simons family and are particular cases of the so-called Lovelock gravities, constructed as the dimensional continuations of the lower dimensional Euler classes. The supersymmetric extensions of these theories exist for the AdS and Poincare groups, and the fields are components of a single connection for the corresponding Lie algebras. In 11 dimensions these supersymmetric theories are gauge theories for the osp(1/32) and the M algebra, respectively. The relation between these new supergravities and the standard theories, as well as some of their dynamical features are also discussed
Inflationary Cosmology: Is Our Universe Part of a Multiverse
International Nuclear Information System (INIS)
Guth, Alan
2008-01-01
In 1981, Guth proposed the theory of the inflationary universe, a modification of the Big Bang theory, which is generally accepted by scientists to explain how the universe began. Nevertheless, the Big Bang theory leaves some questions, and the theory of inflation attempts to answer them. Guth states that a repulsive gravitational force generated by an exotic form of matter brought about the expansion of the universe. He postulates that the universe underwent an expansion of astronomical proportions within the first trillionth of a second of its existence, during which the seeds for its large-scale structure were generated. Guth and colleagues have further explored the possibility of mimicking inflation in a hypothetical laboratory, thereby creating a new universe, and they concluded that it might be theoretically possible. If it happened, the new universe would not endanger our own universe. Instead, it would slip through a wormhole, a hypothetical space-time travel shortcut, and rapidly disconnect from our universe. In this talk, Guth will explain the inflationary theory and review the features that make it scientifically plausible. In addition, he will discuss the biggest mystery in cosmology: Why is the value of the cosmological constant, sometimes called the 'anti-gravity' effect, so remarkably small compared to theoretical expectations? Guth will explain how the inflationary theory, combined with other ideas from elementary particle physics and cosmology, can provide a possible explanation for this discrepancy.
Early universe cosmology. In supersymmetric extensions of the standard model
Energy Technology Data Exchange (ETDEWEB)
Baumann, Jochen Peter
2012-03-19
In this thesis we investigate possible connections between cosmological inflation and leptogenesis on the one side and particle physics on the other side. We work in supersymmetric extensions of the Standard Model. A key role is played by the right-handed sneutrino, the superpartner of the right-handed neutrino involved in the type I seesaw mechanism. We study a combined model of inflation and non-thermal leptogenesis that is a simple extension of the Minimal Supersymmetric Standard Model (MSSM) with conserved R-parity, where we add three right-handed neutrino super fields. The inflaton direction is given by the imaginary components of the corresponding scalar component fields, which are protected from the supergravity (SUGRA) {eta}-problem by a shift symmetry in the Kaehler potential. We discuss the model first in a globally supersymmetric (SUSY) and then in a supergravity context and compute the inflationary predictions of the model. We also study reheating and non-thermal leptogenesis in this model. A numerical simulation shows that shortly after the waterfall phase transition that ends inflation, the universe is dominated by right-handed sneutrinos and their out-of-equilibrium decay can produce the desired matter-antimatter asymmetry. Using a simplified time-averaged description, we derive analytical expressions for the model predictions. Combining the results from inflation and leptogenesis allows us to constrain the allowed parameter space from two different directions, with implications for low energy neutrino physics. As a second thread of investigation, we discuss a generalisation of the inflationary model discussed above to include gauge non-singlet fields as inflatons. This is motivated by the fact that in left-right symmetric, supersymmetric Grand Unified Theories (SUSY GUTs), like SUSY Pati-Salam unification or SUSY SO(10) GUTs, the righthanded (s)neutrino is an indispensable ingredient and does not have to be put in by hand as in the MSSM. We discuss
Early universe cosmology. In supersymmetric extensions of the standard model
International Nuclear Information System (INIS)
Baumann, Jochen Peter
2012-01-01
In this thesis we investigate possible connections between cosmological inflation and leptogenesis on the one side and particle physics on the other side. We work in supersymmetric extensions of the Standard Model. A key role is played by the right-handed sneutrino, the superpartner of the right-handed neutrino involved in the type I seesaw mechanism. We study a combined model of inflation and non-thermal leptogenesis that is a simple extension of the Minimal Supersymmetric Standard Model (MSSM) with conserved R-parity, where we add three right-handed neutrino super fields. The inflaton direction is given by the imaginary components of the corresponding scalar component fields, which are protected from the supergravity (SUGRA) η-problem by a shift symmetry in the Kaehler potential. We discuss the model first in a globally supersymmetric (SUSY) and then in a supergravity context and compute the inflationary predictions of the model. We also study reheating and non-thermal leptogenesis in this model. A numerical simulation shows that shortly after the waterfall phase transition that ends inflation, the universe is dominated by right-handed sneutrinos and their out-of-equilibrium decay can produce the desired matter-antimatter asymmetry. Using a simplified time-averaged description, we derive analytical expressions for the model predictions. Combining the results from inflation and leptogenesis allows us to constrain the allowed parameter space from two different directions, with implications for low energy neutrino physics. As a second thread of investigation, we discuss a generalisation of the inflationary model discussed above to include gauge non-singlet fields as inflatons. This is motivated by the fact that in left-right symmetric, supersymmetric Grand Unified Theories (SUSY GUTs), like SUSY Pati-Salam unification or SUSY SO(10) GUTs, the righthanded (s)neutrino is an indispensable ingredient and does not have to be put in by hand as in the MSSM. We discuss the
Supergravity tensor calculus in 5D from 6D
International Nuclear Information System (INIS)
Kugo, Taichiro; Ohashi, Keisuke
2000-01-01
Supergravity tensor calculus in five spacetime dimensions is derived by dimensional reduction from the d=6 superconformal tensor calculus. In particular, we obtain an off-shell hypermultiplet in 5D from the on-shell hypermultiplet in 6D. Our tensor calculus retains the dilatation gauge symmetry, so that it is a trivial gauge fixing to make the Einstein term canonical in a general matter-Yang-Mills-supergravity coupled system. (author)
The structure of N = 2 supergravity in N = 1 superfields
International Nuclear Information System (INIS)
Awada, M.A.; Mokhtari, S.
1985-01-01
A formulation of N = 2 supergravity in N = 1 superspace is presented. The authors solve up to all orders the N = 2 supergravity constraints in terms of unconstrained N = 1 superfields. The structure of the N = 2 action in N = 1 superspace is examined. The proposed action coincides in the quadratic limit of the spin (3/2,1) matter fields with the action given by previous workers. (author)
Structure of N = 2 supergravity in N = 1 superfields
Energy Technology Data Exchange (ETDEWEB)
Awada, M.A.; Mokhtari, S. (Imperial Coll. of Science and Technology, London (UK). Blackett Lab.)
1985-01-01
A formulation of N = 2 supergravity in N = 1 superspace is presented. The authors solve up to all orders the N = 2 supergravity constraints in terms of unconstrained N = 1 superfields. The structure of the N = 2 action in N = 1 superspace is examined. The proposed action coincides in the quadratic limit of the spin (3/2,1) matter fields with the action given by previous workers.
Effective field theory of dark matter from membrane inflationary paradigm
Choudhury, Sayantan; Dasgupta, Arnab
2016-09-01
In this article, we have studied the cosmological and particle physics constraints on dark matter relic abundance from effective field theory of inflation from tensor-to-scalar ratio (r), in case of Randall-Sundrum single membrane (RSII) paradigm. Using semi-analytical approach we establish a direct connection between the dark matter relic abundance (ΩDMh2) and primordial gravity waves (r), which establishes a precise connection between inflation and generation of dark matter within the framework of effective field theory in RSII membrane. Further assuming the UV completeness of the effective field theory perfectly holds good in the prescribed framework, we have explicitly shown that the membrane tension, σ ≤ O(10-9) Mp4 , bulk mass scale M5 ≤ O(0.04 - 0.05) Mp, and cosmological constant Λ˜5 ≥ - O(10-15) Mp5 , in RSII membrane plays the most significant role to establish the connection between dark matter and inflation, using which we have studied the features of various mediator mass scale suppressed effective field theory "relevant operators" induced from the localized s, t and u channel interactions in RSII membrane. Taking a completely model independent approach, we have studied an exhaustive list of tree-level Feynman diagrams for dark matter annihilation within the prescribed setup and to check the consistency of the obtained results, further we apply the constraints as obtained from recently observed Planck 2015 data and Planck + BICEP2 + Keck Array joint data sets. Using all of these derived results we have shown that to satisfy the bound on, ΩDMh2 = 0.1199 ± 0.0027, as from Planck 2015 data, it is possible to put further stringent constraint on r within, 0.01 ≤ r ≤ 0.12, for thermally averaged annihilation cross-section of dark matter, 〈 σv 〉 ≈ O(10-28 - 10-27) cm3 / s, which are very useful to constrain various membrane inflationary models.
Off shell N=1 supergravity theory in six dimensions
International Nuclear Information System (INIS)
Smith, A.W.
1983-01-01
The off shell N=1 supergravity theory in six dimensions shows beneath the extreme simplicity of theories in higher dimensions useful properties for the study of a unification of normal gauge theories with the supergravity theory via dimensional reduction and yields a geometrical interpretation for the quantum numbers of internal symmtries of the reduced theory. Furthermore this theory permits a better understanding of ultraviolet divergences than a theory in four dimensions. This six-dimensional supergravity theory is constructed here in the corresponding superspace the importance of which was clained otherwise because a precisely defined mathematical formalism for this exists: Differential geometry in the superspace. We establish constraining conditions for the torsion components and give a complete solution of the Bianchi identities. In the formulation of the conditions for the torsions exists a certain freedom, because different conditions lead to the same solution. Therefore only the analysis of the Bianchi identities will show wether the conditions are too restrictive or not. Furthermore the dimensional reduction of D=6 to the four-dimensional space-time is performed. We show here that the reduced theory yields the conformal N=2 supergravity theory. In the last part of this thesis a Langrangian is presented by which the supergravity is coupled to a matter multiplet. In the analysis of the supersymmetry transformations of the component fields we see that the matter multiplet cannot be consistently brought to vanish. That means that a pure supergravity theory cannot be written manifestly Lorentz covariant. (orig.) [de
Phenomenology of the minimal inflation scenario: inflationary trajectories and particle production
Alvarez-Gaume, Luis; Jimenez, Raul
2012-01-01
We discuss the phenomenology of the minimal inflation scenario. We concentrate on two aspects: inflationary trajectories and particle production. Our findings can be summarized in two main results: first, that inflationary trayectories that are very flat and provide enough number of e-foldings are very natural in the scenario without fine tunning. We present a general formalism to identify attractors in multi-field inflation regardless of trajectories fulfilling the slow-roll conditions. We then explore particle production in the model and show how the inflaton naturally transmutes into the current dark matter particle, thus providing a mechanism to identify the inflaton today: it is the dark matter. One interesting feature of our model is that it provides a novel mechanism to generate particles and entropy in the universe: the filling of the Fermi sphere up to a given momentum pF due to the sea of goldstinos that are an important part of the matter generated after inflation. With this mechanism in hand we pr...
Frame-dependence of higher-order inflationary observables in scalar-tensor theories
Karam, Alexandros; Pappas, Thomas; Tamvakis, Kyriakos
2017-09-01
In the context of scalar-tensor theories of gravity we compute the third-order corrected spectral indices in the slow-roll approximation. The calculation is carried out by employing the Green's function method for scalar and tensor perturbations in both the Einstein and Jordan frames. Then, using the interrelations between the Hubble slow-roll parameters in the two frames we find that the frames are equivalent up to third order. Since the Hubble slow-roll parameters are related to the potential slow-roll parameters, we express the observables in terms of the latter which are manifestly invariant. Nevertheless, the same inflaton excursion leads to different predictions in the two frames since the definition of the number of e -folds differs. To illustrate this effect we consider a nonminimal inflationary model and find that the difference in the predictions grows with the nonminimal coupling, and it can actually be larger than the difference between the first and third order results for the observables. Finally, we demonstrate the effect of various end-of-inflation conditions on the observables. These effects will become important for the analyses of inflationary models in view of the improved sensitivity of future experiments.
Unification of inflation, dark energy, and dark matter within the Salam-Sezgin cosmological model
International Nuclear Information System (INIS)
Henriques, Alfredo B.; Potting, Robertus; Sa, Paulo M.
2009-01-01
We investigate a cosmological model, based on the Salam-Sezgin six-dimensional supergravity theory and on previous work by Anchordoqui, Goldberg, Nawata, and Nunez. Assuming a period of warm inflation, we show that it is possible to extend the evolution of the model back in time, to include the inflationary period, thus unifying inflation, dark matter, and dark energy within a single framework. Like the previous authors, we were not able to obtain the full dark matter content of the universe from the Salam-Sezgin scalar fields. However, even if only partially successful, this work shows that present-day theories, based on superstrings and supergravity, may eventually lead to a comprehensive modeling of the evolution of the universe. We find that the gravitational-wave spectrum of the model has a nonconstant negative slope in the frequency range (10 -15 -10 6 ) rad/s, and that, unlike standard (cold) inflation models, it shows no structure in the MHz/GHz range of frequencies.
Higher derivative corrections to BPS black hole attractors in 4d gauged supergravity
Energy Technology Data Exchange (ETDEWEB)
Hristov, Kiril [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Tsarigradsko Chaussee 72, 1784 Sofia (Bulgaria); Katmadas, Stefanos [Dipartimento di Fisica, Università di Milano-Bicocca,I-20126 Milano (Italy); INFN, Sezione di Milano-Bicocca,I-20126 Milano (Italy); Lodato, Ivano [Department of Physics, IISER Pune,Homi Bhaba Road, Pashan, Pune (India)
2016-05-30
We analyze BPS black hole attractors in 4d gauged supergravity in the presence of higher derivative supersymmetric terms, including a Weyl-squared-type action, and determine the resulting corrections to the Bekenstein-Hawking entropy. The near-horizon geometry AdS{sub 2}×S{sup 2} (or other Riemann surface) preserves half of the supercharges in N=2 supergravity with Fayet-Iliopoulos gauging. We derive a relation between the entropy and the black hole charges that suggests via AdS/CFT how subleading corrections contribute to the supersymmetric index in the dual microscopic picture. Depending on the model, the attractors are part of full black hole solutions with different asymptotics, such as Minkowski, AdS{sub 4}, and hvLif{sub 4}. We give explicit examples for each of the asymptotic cases and comment on the implications. Among other results, we find that the Weyl-squared terms spoil the exact two-derivative relation to non-BPS asymptotically flat black holes in ungauged supergravity.
Primordial perturbations with pre-inflationary bounce
Cai, Yong; Wang, Yu-Tong; Zhao, Jin-Yun; Piao, Yun-Song
2018-05-01
Based on the effective field theory (EFT) of nonsingular cosmologies, we build a stable model, without the ghost and gradient instabilities, of bounce-inflation (inflation is preceded by a cosmological bounce). We perform a full simulation for the evolution of scalar perturbation, and find that the perturbation spectrum has a large-scale suppression (as expected), which is consistent with the power deficit of the cosmic microwave background (CMB) TT-spectrum at low multipoles, but unexpectedly, it also shows itself one marked lower valley. The depth of valley is relevant with the physics around the bounce scale, which is model-dependent.
Effects of heavy fields on inflationary cosmology
Ortiz, Pablo
2014-01-01
Cosmological inflation is the most successful theory that explains the homogeneity and flatness of the early universe. It also provides a quantum origin for the primordial perturbations that we observe in the Cosmic Microwave Background Radiation (CMB). The simplest models make use of a single
The reconstruction of tachyon inflationary potentials
Energy Technology Data Exchange (ETDEWEB)
Fei, Qin; Gong, Yungui; Lin, Jiong; Yi, Zhu, E-mail: feiqin@hust.edu.cn, E-mail: yggong@mail.hust.edu.cn, E-mail: 707751841@qq.com, E-mail: yizhu92@hust.edu.cn [School of Physics, Huazhong University of Science and Technology, 1037 LuoYu Rd, Wuhan, Hubei 430074 (China)
2017-08-01
We derive a lower bound on the field excursion for the tachyon inflation, which is determined by the amplitude of the scalar perturbation and the number of e -folds before the end of inflation. Using the relation between the observables like n {sub s} and r with the slow-roll parameters, we reconstruct three classes of tachyon potentials. The model parameters are determined from the observations before the potentials are reconstructed, and the observations prefer the concave potential. We also discuss the constraints from the reheating phase preceding the radiation domination for the three classes of models by assuming the equation of state parameter w {sub re} during reheating is a constant. Depending on the model parameters and the value of w {sub re} , the constraints on N {sub re} and T {sub re} are different. As n {sub s} increases, the allowed reheating epoch becomes longer for w {sub re} =−1/3, 0 and 1/6 while the allowed reheating epoch becomes shorter for w {sub re} =2/3.
Inflationary cosmology from quantum conformal gravity
International Nuclear Information System (INIS)
Jizba, Petr; Kleinert, Hagen; Scardigli, Fabio
2015-01-01
We analyze the functional integral for quantum conformal gravity and show that, with the help of a Hubbard-Stratonovich transformation, the action can be broken into a local quadratic-curvature theory coupled to a scalar field. A one-loop effective-action calculation reveals that strong fluctuations of the metric field are capable of spontaneously generating a dimensionally transmuted parameter which, in the weak-field sector of the broken phase, induces a Starobinsky-type f(R)-model with a gravi-cosmological constant. A resulting non-trivial relation between Starobinsky's parameter and the gravi-cosmological constant is highlighted and implications for cosmic inflation are briefly discussed and compared with the recent PLANCK and BICEP2 data. (orig.)
Viscous coupled fluids in inflationary cosmology
Energy Technology Data Exchange (ETDEWEB)
Brevik, I., E-mail: iver.h.brevik@ntnu.no [Norwegian University of Science and Technology (Norway); Timoshkin, A. V., E-mail: timoshkinAV@tspu.edu.ru [Tomsk State Pedagogical University (Russian Federation)
2016-04-15
We consider the inflation produced by two coupled fluids in a flat Friedmann–Robertson–Walker universe. Different cosmological models for describing inflation with the use of an inhomogeneous equation of state for the fluid are investigated. The gravitational equations for energy and matter are solved, and analytic representations for the Hubble parameter and the energy density are obtained. Corrections to the energy density for matter inducing the inflation and the coupling to energy are discussed. We analyze the description of inflation induced by nonconstant equation-of-state parameters from fluid viscosity. The correspondence between the spectral index and the tensor-to-scalar ratio recently observed by the Planck satellite is considered.
The behavior of the Higgs field in the new inflationary universe
Guth, Alan H.; Pi, So-Young
1986-01-01
Answers are provided to questions about the standard model of the new inflationary universe (NIU) which have raised concerns about the model's validity. A baby toy problem which consists of the study of a single particle moving in one dimension under the influence of a potential with the form of an upside-down harmonic oscillator is studied, showing that the quantum mechanical wave function at large times is accurately described by classical physics. Then, an exactly soluble toy model for the behavior of the Higgs field in the NIU is described which should provide a reasonable approximation to the behavior of the Higgs field in the NIU. The dynamics of the toy model is described, and calculative results are reviewed which, the authors claim, provide strong evidence that the basic features of the standard picture are correct.
On minimal coupling of the ABC-superparticle to supergravity background
Galajinsky, A. V.; Gitman, D. M.
1998-01-01
By rigorous application of the Hamiltonian methods we show that the ABC-formulation of the Siegel superparticle admits consistent minimal coupling to external supergravity. The consistency check proves to involve all the supergravity constraints.
A complete solution of the Bianchi identities in superspace with supergravity constraints
International Nuclear Information System (INIS)
Grimm, R.; Wess, J.; Zumino, B.
1979-01-01
A short discussion of the superspace formulation of supergravity is given and the Bianchi identities are derived. The supergravity constraints are imposed and the identities are solved in terms of superfields and their covariant derivatives. (Auth.)
Cosmological perturbations in the entangled inflationary universe
Robles-Pérez, Salvador J.
2018-03-01
In this paper, the model of a multiverse made up of universes that are created in entangled pairs that conserve the total momentum conjugated to the scale factor is presented. For the background spacetime, assumed is a Friedmann-Robertson-Walker metric with a scalar field with mass m minimally coupled to gravity. For the fields that propagate in the entangled spacetimes, the perturbations of the spacetime and the scalar field, whose quantum states become entangled too, are considered. They turn out to be in a quasithermal state, and the corresponding thermodynamical magnitudes are computed. Three observables are expected to be caused by the creation of the universes in entangled pairs: a modification of the Friedmann equation because of the entanglement of the spacetimes, a modification of the effective value of the potential of the scalar field by the backreaction of the perturbation modes, and a modification of the spectrum of fluctuations because the thermal distribution is induced by the entanglement of the partner universes. The later would be a distinctive feature of the creation of universes in entangled pairs.
Vacua and inflation in string theory and supergravity
International Nuclear Information System (INIS)
Rummel, Markus
2013-07-01
We study the connection between the early and late accelerated expansion of the universe and string theory. In Part I of this thesis, the observational degeneracy between single field models of inflation with canonical kinetic terms and noncanonical kinetic terms, in particular string theory inspired models, is discussed. The 2-point function observables of a given non-canonical theory and its canonical transform that is obtained by matching the inflationary trajectories in phase space are found to match in the case of Dirac-Born-Infeld (DBI) inflation. At the level of the 3-point function observables (non-Gaussianities), we find degeneracy between non-canonical inflation and canonical inflation with a potential that includes a sum of modulated terms. In Part II, we present explicit examples for de Sitter vacua in type IIB string theory. After deriving a sufficient condition for de Sitter vacua in the Kahler uplifting scenario, we show that a globally consistent de Sitter model can be realized on a certain Calabi-Yau manifold. All geometric moduli are stabilized and all known consistency constraints are fulfilled. The complex structure moduli stabilization by fluxes is studied explicitly for a small number of cycles. Extrapolating to a larger number of flux carrying cycles, we verify statistical studies in the literature which show that, in principle, the string landscape can account for a universe with an extremely small cosmological constant.
Vacua and inflation in string theory and supergravity
Energy Technology Data Exchange (ETDEWEB)
Rummel, Markus
2013-07-15
We study the connection between the early and late accelerated expansion of the universe and string theory. In Part I of this thesis, the observational degeneracy between single field models of inflation with canonical kinetic terms and noncanonical kinetic terms, in particular string theory inspired models, is discussed. The 2-point function observables of a given non-canonical theory and its canonical transform that is obtained by matching the inflationary trajectories in phase space are found to match in the case of Dirac-Born-Infeld (DBI) inflation. At the level of the 3-point function observables (non-Gaussianities), we find degeneracy between non-canonical inflation and canonical inflation with a potential that includes a sum of modulated terms. In Part II, we present explicit examples for de Sitter vacua in type IIB string theory. After deriving a sufficient condition for de Sitter vacua in the Kahler uplifting scenario, we show that a globally consistent de Sitter model can be realized on a certain Calabi-Yau manifold. All geometric moduli are stabilized and all known consistency constraints are fulfilled. The complex structure moduli stabilization by fluxes is studied explicitly for a small number of cycles. Extrapolating to a larger number of flux carrying cycles, we verify statistical studies in the literature which show that, in principle, the string landscape can account for a universe with an extremely small cosmological constant.
Supergravity on an Atiyah-Hitchin base
International Nuclear Information System (INIS)
Stotyn, Sean; Mann, R.B.
2008-01-01
We construct solutions to five dimensional minimal supergravity using an Atiyah-Hitchin base space. In examining the structure of solutions we show that they generically contain a singularity either on the Atiyah-Hitchin bolt or at larger radius where there is a singular solitonic boundary. However for most points in parameter space the solution exhibits a velocity of light surface (analogous to what appears in a Goedel space-time) that shields the singularity. For these solutions, all closed time-like curves are causally disconnected from the rest of the space-time in that they exist within the velocity of light surface, which null geodesics are unable to cross. The singularities in these solutions are thus found to be hidden behind the velocity of light surface and so are not naked despite the lack of an event horizon. Outside of this surface the space-time is geodesically complete, asymptotically flat and can be arranged so as not to contain closed time-like curves at infinity. The rest of parameter space simply yields solutions with naked singularities.
Higher-Derivative Supergravity and Moduli Stabilization
International Nuclear Information System (INIS)
Ciupke, David; Westphal, Alexander; Louis, Jan; Hamburg Univ.
2015-05-01
We review the ghost-free four-derivative terms for chiral superfields in N=1 supersymmetry and supergravity. These terms induce cubic polynomial equations of motion for the chiral auxiliary fields and correct the scalar potential. We discuss the different solutions and argue that only one of them is consistent with the principles of effective field theory. Special attention is paid to the corrections along flat directions which can be stabilized or destabilized by the higher-derivative terms. We then compute these higher-derivative terms explicitly for the type IIB string compactified on a Calabi-Yau orientifold with fluxes via Kaluza-Klein reducing the (α') 3 R 4 corrections in ten dimensions for the respective N=1 Kaehler moduli sector. We prove that together with flux and the known (α') 3 -corrections the higher-derivative term stabilizes all Calabi-Yau manifolds with positive Euler number, provided the sign of the new correction is negative.
International Nuclear Information System (INIS)
Kuroyanagi, Sachiko; Chiba, Takeshi; Sugiyama, Naoshi
2011-01-01
We study the potential impact of detecting the inflationary gravitational wave background by the future space-based gravitational wave detectors, such as DECIGO and BBO. The signal-to-noise ratio of each experiment is calculated for chaotic/natural/hybrid inflation models by using the precise predictions of the gravitational wave spectrum based on numerical calculations. We investigate the dependence of each inflation model on the reheating temperature which influences the amplitude and shape of the spectrum, and find that the gravitational waves could be detected for chaotic/natural inflation models with high reheating temperature. From the detection of the gravitational waves, a lower bound on the reheating temperature could be obtained. The implications of this lower bound on the reheating temperature for particle physics are also discussed.
R4 terms in supergravities via T -duality constraint
Razaghian, Hamid; Garousi, Mohammad R.
2018-05-01
It has been speculated in the literature that the effective actions of string theories at any order of α' should be invariant under the Buscher rules plus their higher covariant-derivative corrections. This may be used as a constraint to find effective actions at any order of α', in particular, the metric, the B -field, and the dilaton couplings in supergravities at order α'3 up to an overall factor. For the simple case of zero B -field and diagonal metric in which we have done the calculations explicitly, we have found that the constraint fixes almost all of the seven independent Riemann curvature couplings. There is only one term which is not fixed, because when metric is diagonal, the reduction of two R4 terms becomes identical. The Riemann curvature couplings that the T -duality constraint produces for both type II and heterotic theories are fully consistent with the existing couplings in the literature which have been found by the S-matrix and by the sigma-model approaches.
Summing up D-instantons in N=2 supergravity
International Nuclear Information System (INIS)
Ketov, Sergei V.
2003-01-01
The non-perturbative quantum geometry of the universal hypermultiplet (UH) is investigated in N=2 supergravity. The UH low-energy effective action is given by the four-dimensional quaternionic non-linear sigma-model having an U(1)xU(1) isometry. The UH metric is governed by the single real pre-potential that is an eigenfunction of the Laplacian in the hyperbolic plane. We calculate the classical pre-potential corresponding to the standard (Ferrara-Sabharwal) metric of the UH arising in the Calabi-Yau compactification of type-II superstrings. The non-perturbative quaternionic metric, describing the D-instanton contributions to the UH geometry, is found by requiring the SL(2,Z) modular invariance of the UH pre-potential. The pre-potential found is unique, while it coincides with the D-instanton function of Green and Gutperle, given by the order-3/2 Eisenstein series. As a by-product, we prove cluster decomposition of D-instantons in curved spacetime. The non-perturbative UH pre-potential interpolates between the perturbative (large CY volume) region and the superconformal (Landau-Ginzburg) region in the UH moduli space. We also calculate a non-perturbative scalar potential in the hyper-Kaehler limit, when an abelian isometry of the UH metric is gauged in the presence of D-instantons
Split Attractor Flow in N=2 Minimally Coupled Supergravity
Ferrara, Sergio; Orazi, Emanuele
2011-01-01
We classify the stability region, marginal stability walls (MS) and split attractor flows for two-center extremal black holes in four-dimensional N=2 supergravity minimally coupled to n vector multiplets. It is found that two-center (continuous) charge orbits, classified by four duality invariants, either support a stability region ending on a MS wall or on an anti-marginal stability (AMS) wall, but not both. Therefore, the scalar manifold never contains both walls. Moreover, the BPS mass of the black hole composite (in its stability region) never vanishes in the scalar manifold. For these reasons, the "bound state transformation walls" phenomenon does not necessarily occur in these theories. The entropy of the flow trees also satisfies an inequality which forbids "entropy enigma" decays in these models. Finally, the non-BPS case, due to the existence of a "fake" superpotential satisfying a triangle inequality, can be treated as well, and it can be shown to exhibit a split attractor flow dynamics which, at le...
Summing up D-instantons in N=2 supergravity
Energy Technology Data Exchange (ETDEWEB)
Ketov, Sergei V. E-mail: ketov@phys.metro-u.ac.jp
2003-01-20
The non-perturbative quantum geometry of the universal hypermultiplet (UH) is investigated in N=2 supergravity. The UH low-energy effective action is given by the four-dimensional quaternionic non-linear sigma-model having an U(1)xU(1) isometry. The UH metric is governed by the single real pre-potential that is an eigenfunction of the Laplacian in the hyperbolic plane. We calculate the classical pre-potential corresponding to the standard (Ferrara-Sabharwal) metric of the UH arising in the Calabi-Yau compactification of type-II superstrings. The non-perturbative quaternionic metric, describing the D-instanton contributions to the UH geometry, is found by requiring the SL(2,Z) modular invariance of the UH pre-potential. The pre-potential found is unique, while it coincides with the D-instanton function of Green and Gutperle, given by the order-3/2 Eisenstein series. As a by-product, we prove cluster decomposition of D-instantons in curved spacetime. The non-perturbative UH pre-potential interpolates between the perturbative (large CY volume) region and the superconformal (Landau-Ginzburg) region in the UH moduli space. We also calculate a non-perturbative scalar potential in the hyper-Kaehler limit, when an abelian isometry of the UH metric is gauged in the presence of D-instantons.
On-shell diagrams for N=8 supergravity amplitudes
Energy Technology Data Exchange (ETDEWEB)
Heslop, Paul; Lipstein, Arthur E. [Department of Mathematical Sciences, Durham University,Lower Mountjoy, Stockton Road, Durham, DH1 3LE (United Kingdom)
2016-06-10
We define recursion relations for N=8 supergravity amplitudes using a generalization of the on-shell diagrams developed for planar N=4 super-Yang-Mills. Although the recursion relations generically give rise to non-planar on-shell diagrams, we show that at tree-level the recursion can be chosen to yield only planar diagrams, the same diagrams occurring in the planar N=4 theory. This implies non-trivial identities for non-planar diagrams as well as interesting relations between the N=4 and N=8 theories. We show that the on-shell diagrams of N=8 supergravity obey equivalence relations analogous to those of N=4 super-Yang-Mills, and we develop a systematic algorithm for reading off Grassmannian integral formulae directly from the on-shell diagrams. We also show that the 1-loop 4-point amplitude of N=8 supergravity can be obtained from on-shell diagrams.
Brane induced supersymmetry breaking and de Sitter 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); Martucci, Luca [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); I.N.F.N. Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Sorokin, Dmitri [I.N.F.N. Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); Tonin, Mario [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); I.N.F.N. Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy)
2016-02-12
We obtain a four-dimensional supergravity with spontaneously broken supersymmetry allowing for de Sitter vacua by coupling a superspace action of minimal N=1, D=4 supergravity to a locally supersymmetric generalization of the Volkov-Akulov goldstino action describing the dynamics of a space-filling non-BPS 3-brane in N=1, D=4 superspace. To the quadratic order in the goldstino field the obtained action coincides with earlier constructions of supergravities with nilpotent superfields, while matching the higher-order contributions will require a non-linear redefinition of fields. In the unitary gauge, in which the goldstino field is set to zero, the action coincides with that of Volkov and Soroka. We also show how a nilpotency constraint on a chiral curvature superfield emerges in this formulation.
Invariant Killing spinors in 11D and type II supergravities
International Nuclear Information System (INIS)
Gran, U; Gutowski, J; Papadopoulos, G
2009-01-01
We present all isotropy groups and associated Σ groups, up to discrete identifications of the component connected to the identity, of spinors of 11-dimensional and type II supergravities. The Σ groups are products of a Spin group and an R-symmetry group of a suitable lower dimensional supergravity theory. Using the case of SU(4)-invariant spinors as a paradigm, we demonstrate that the Σ groups, and so the R-symmetry groups of lower dimensional supergravity theories arising from compactifications, have disconnected components. These lead us to discrete symmetry groups reminiscent of R-parity. We examine the role of disconnected components of the Σ groups in the choice of Killing spinor representatives and in the context of compactifications.
An N=2 gauge theory and its supergravity dual
Brandhuber, A
2000-01-01
We study flows on the scalar manifold of N=8 gauged supergravity in five dimensions which are dual to certain mass deformations of N=4 super Yang-Mill theory. In particular, we consider a perturbation of the gauge theory by a mass term for the adjoint hyper-multiplet, giving rise to an N=2 theory. The exact solution of the 5-dim gauged supergravity equations of motion is found and the metric is uplifted to a ten-dimensional background of type-IIB supergravity. Using these geometric data and the AdS/CFT correspondence we analyze the spectra of certain operators as well as Wilson loops on the dual gauge theory side. The physical flows are parametrized by a single non-positive constant and describe part of the Coulomb branch of the N=2 theory at strong coupling.
On the consistency of classical and quantum supergravity theories
Energy Technology Data Exchange (ETDEWEB)
Hack, Thomas-Paul [II. Institute for Theoretical Physics, University of Hamburg (Germany); Makedonski, Mathias [Department of Mathematical Sciences, University of Copenhagen (Denmark); Schenkel, Alexander [Department of Stochastics, University of Wuppertal (Germany)
2012-07-01
It is known that pure N=1 supergravity in d=4 spacetime dimensions is consistent at a classical and quantum level, i.e. that in a particular gauge the field equations assume a hyperbolic form - ensuring causal propagation of the degrees of freedom - and that the associated canonical quantum field theory satisfies unitarity. It seems, however, that it is yet unclear whether these properties persist if one considers the more general and realistic case of N=1, d=4 supergravity theories including arbitrary matter fields. We partially clarify the issue by introducing novel hyperbolic gauges for the gravitino field and proving that they commute with the resulting equations of motion. Moreover, we review recent partial results on the unitarity of these general supergravity theories and suggest first steps towards a comprehensive unitarity proof.
The component structure of conformal supergravity invariants in six dimensions
Energy Technology Data Exchange (ETDEWEB)
Butter, Daniel [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); George and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University,College Station, TX 77843 (United States); Novak, Joseph [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, D-14476 Golm (Germany); Tartaglino-Mazzucchelli, Gabriele [Instituut voor Theoretische Fysica, KU Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium)
2017-05-24
In the recent paper https://arxiv.org/abs/1606.02921, the two invariant actions for 6D N=(1,0) conformal supergravity were constructed in superspace, corresponding to the supersymmetrization of C{sup 3} and C◻C. In this paper, we provide the translation from superspace to the component formulation of superconformal tensor calculus, and we give the full component actions of these two invariants. As a second application, we build the component form for the supersymmetric F◻F action coupled to conformal supergravity. Exploiting the fact that the N=(2,0) Weyl multiplet has a consistent truncation to N=(1,0), we then verify that there is indeed only a single N=(2,0) conformal supergravity invariant and reconstruct most of its bosonic terms by uplifting a certain linear combination of N=(1,0) invariants.
Complex superspaces and prepotentials for N = 2 supergravity
International Nuclear Information System (INIS)
Sokatchev, E.
1981-01-01
A prepotential formulation of N=2 supergravity is constructed as a generalization of the non-minimal N=1 case. The non-minimal and minimal prepotential formulations of N=1 supergravity are briefly reviewed, the non-minimal case is then generalized to from the basis of the N=2 theory. The action of the Lorentz structure group is extracted from the transformation law of the spinar derivatives. Vielbeins and connections are defined and expressed in terms of the prepotentials. In evaluation of the torsion components the normal gauge technique is applied. The possibility of using the invariant volume of the chiral superspaces as an action for the N=2 supergravity is considered. (author)
On moduli spaces in AdS{sub 4} supergravity
Energy Technology Data Exchange (ETDEWEB)
Alwis, Senarath de [Colorado Univ., Boulder, CO (United States). Dept. of Physics; Louis, Jan [Hamburg Univ. (Germany). Fachbereich 12 - Physik; Hamburg Univ. (Germany). Zentrum fuer Mathematische Physik; McAllister, Liam [Cornell Univ., Ithaca, NY (United States). Dept. of Physics; Triendl, Hagen [CERN, Geneva (Switzerland). Theory Division, Physics Dept.; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie
2013-12-15
We study the structure of the supersymmetric moduli spaces of N=1 and N=2 supergravity theories in AdS{sub 4} backgrounds. In the N=1 case, the moduli space cannot be a complex submanifold of the Kaehler field space, but is instead real with respect to the inherited complex structure. In N=2 supergravity the same result holds for the vector multiplet moduli space, while the hypermultiplet moduli space is a Kaehler submanifold of the quaternionic-Kaehler field space. These findings are in agreement with AdS/CFT considerations.
Differential and integral forms in supergauge theories and supergravity
International Nuclear Information System (INIS)
Zupnik, B.M.; Pak, D.G.
1989-01-01
D = 3, 4, N = 1 supergauge theories and D = 3, N = 1 supergravity are considered in the superfield formalism by using differential and integral forms. A special map of the space of differential forms into the space of integral forms is proposed. By means of this map we find the superfield Chern-Simons terms in D = 3, N = 1 Yang-Mills theory and supergravity. The integral forms corresponding to superfield invariants of D = 4, N = 1 supergauge theory have also been constructed. (Author)
Supersymmetric couplings and trajectories in N = 1 supergravity
International Nuclear Information System (INIS)
Castagnino, M.; Umerez, N.; Domenech, G.; Levinas, M.
1989-01-01
The present work deals with the classical behaviour of matter represented by chiral multiplets in a background of N = 1 supergravity. The WKB method is used. It is shown that supersymmetric coupling leads, at the lowest order, to a non-geodesic motion law for spin-1/2 matter. This result permits us to establish physical differences with respect to gravitational theories with minimal coupled matter Lagrangians. Deviations from the Newton law are found, allowing us to speculate about low-energy effects for testing supergravity. (author)
6D supergravity. Warped solution and gravity mediated supersymmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Luedeling, C
2006-07-15
We consider compactified six-dimensional gauged supergravity and find the general warped solution with four-dimensional maximal symmetry. Important features of the solution such as the number and position of singularities are determined by a free holomorphic function. Furthermore, in a particular torus compactification we derive the supergravity coupling of brane fields by the Noether procedure and investigate gravity-mediated supersymmetry breaking. The effective Kaehler potential is not sequestered, yet tree level gravity mediation is absent as long as the superpotential is independent of the radius modulus. (orig.)
6D supergravity. Warped solution and gravity mediated supersymmetry breaking
International Nuclear Information System (INIS)
Luedeling, C.
2006-07-01
We consider compactified six-dimensional gauged supergravity and find the general warped solution with four-dimensional maximal symmetry. Important features of the solution such as the number and position of singularities are determined by a free holomorphic function. Furthermore, in a particular torus compactification we derive the supergravity coupling of brane fields by the Noether procedure and investigate gravity-mediated supersymmetry breaking. The effective Kaehler potential is not sequestered, yet tree level gravity mediation is absent as long as the superpotential is independent of the radius modulus. (orig.)
d=3 Chern-Simons action, supergravity and quantization
International Nuclear Information System (INIS)
Dayi, O.F.
1989-01-01
An interpretation of three-dimensional simple supergravity as a pure Chern-Simons gauge action is shown to be valid up to the one loop level. Canonical quantization of this system does not lead to an explicit definition of the physical Hilbert space. Hence another formulation of the N = 1 three-dimensional supergravity is introduced. In this formalism an explicit definition of the physical Hilbert space is possible, but still one has to solve the problems of showing that there exists a global set of coordinates and of defining the inner product. (author). 10 refs
Extremal Black Holes in Supergravity and the Bekenstein-Hawking Entropy
Directory of Open Access Journals (Sweden)
R. D'Auria
2002-03-01
Full Text Available Abstract: We review some results on the connection among supergravity central charges, BPS states and Bekenstein-Hawking entropy. In particular, N = 2 super-gravity in four dimensions is studied in detail. For higher N supergravities we just give an account of the general theory specializing the discussion to the N = 8 case when one half of supersymmetry is preserved. We stress the fact that for extremal supergravity black holes the entropy formula is topological, that is the entropy turns out to be a moduli independent quantity and can be written in terms of invariants of the duality group of the supergravity theory.
Vaidya--Patel solution with Robertson--Walker metric as a rotating inflationary scenario
International Nuclear Information System (INIS)
Groen, O.; Soleng, H.H.
1988-01-01
The Vaidya--Patel solution of a rotating homogeneous fluid in the presence of a Maxwellian source-free electromagnetic field is interpretated as an inflationary scenario with a gauge field with local U(1) symmetry, a vacuum energy, and a rotating perfect fluid. An explicit solution is found to be expressible in terms of known solutions representing the radiation filled Robertson--Walker universe with a cosmological term. In the case that the rotating fluid is radiation, the discussion of the model is considerably simplified. How the time scale of transition into a pseudo-de Sitter stage, as observed by an observer following the rotating fluid, is affected by vorticity is also studied
Matter and gauge couplings of N=2 supergravity in six dimensions
International Nuclear Information System (INIS)
Nishino, H.; Sezgin, E.
1984-04-01
We construct the couplings of a single anti-symmetric tensor multiplet, the non-compact HP(n-1,1) identical Sp(n,1)/Sp(n)xSp(1) σ-model and a Yang-Mills multiplet with the local gauge group Sp(n)xSp(1) to N=2 supergravity in d=6. The theory has a positive definite potential. If only the Sp(n) group is gauged, we can use the global Sp(1) invariance to realize a super-Higgs effect a la Scherk and Schwarz. [Nucl. Phys. B153, 61(1979)]. (author)
Frequentist analysis of the parameter space of minimal supergravity
Energy Technology Data Exchange (ETDEWEB)
Buchmueller, O.; Colling, D. [Imperial College, London (United Kingdom). High Energy Physics Group; Cavanaugh, R. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Illinois Univ., Chicago, IL (US). Physics Dept.] (and others)
2010-12-15
We make a frequentist analysis of the parameter space of minimal supergravity (mSUGRA), in which, as well as the gaugino and scalar soft supersymmetry-breaking parameters being universal, there is a specific relation between the trilinear, bilinear and scalar supersymmetry-breaking parameters, A{sub 0}=B{sub 0}+m{sub 0}, and the gravitino mass is fixed by m{sub 3/2}=m{sub 0}. We also consider a more general model, in which the gravitino mass constraint is relaxed (the VCMSSM). We combine in the global likelihood function the experimental constraints from low-energy electroweak precision data, the anomalous magnetic moment of the muon, the lightest Higgs boson mass M{sub h}, B physics and the astrophysical cold dark matter density, assuming that the lightest supersymmetric particle (LSP) is a neutralino. In the VCMSSM, we find a preference for values of m{sub 1/2} and m{sub 0} similar to those found previously in frequentist analyses of the constrained MSSM (CMSSM) and a model with common non-universal Higgs masses (NUHM1). On the other hand, in mSUGRA we find two preferred regions: one with larger values of both m{sub 1/2} and m{sub 0} than in the VCMSSM, and one with large m{sub 0} but small m{sub 1/2}. We compare the probabilities of the frequentist fits in mSUGRA, the VCMSSM, the CMSSM and the NUHM1: the probability that mSUGRA is consistent with the present data is significantly less than in the other models. We also discuss the mSUGRA and VCMSSM predictions for sparticle masses and other observables, identifying potential signatures at the LHC and elsewhere. (orig.)
Directory of Open Access Journals (Sweden)
Madhu Jain
2014-01-01
Full Text Available The present study is concerned with the cost modeling of an inventory system with perishable multi-items having stock dependent demand rates under an inflationary environment of the market. The concept of permissible delay is taken into account. The study provides the cost analysis of inventory system under the decision criteria of time value of money, inflation, deterioration, and stock dependent demand. Numerical illustrations are derived from the quantitative model to validate the results. The cost of inventory and optimal time are also computed by varying different system parameters. The comparison of these results is facilitated by computing the results with neurofuzzy results.
Simple emergent power spectra from complex inflationary physics
Energy Technology Data Exchange (ETDEWEB)
Dias, Mafalda; Frazer, Jonathan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Marsh, M.C. David [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics (DAMTP)
2016-04-15
We construct ensembles of random scalar potentials for N{sub f} interacting scalar fields using non-equilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For N{sub f}=O(few), these heavily featured scalar potentials give rise to power spectra that are highly non-linear, at odds with observations. For N{sub f}>>1, the superhorizon evolution of the perturbations is generically substantial, yet the power spectra simplify considerably and become more predictive, with most realisations being well approximated by a linear power spectrum. This provides proof of principle that complex inflationary physics can give rise to simple emergent power spectra. We explain how these results can be understood in terms of large N{sub f} universality of random matrix theory.
Simple emergent power spectra from complex inflationary physics
International Nuclear Information System (INIS)
Dias, Mafalda; Frazer, Jonathan; Marsh, M.C. David
2016-04-01
We construct ensembles of random scalar potentials for N f interacting scalar fields using non-equilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For N f =O(few), these heavily featured scalar potentials give rise to power spectra that are highly non-linear, at odds with observations. For N f >>1, the superhorizon evolution of the perturbations is generically substantial, yet the power spectra simplify considerably and become more predictive, with most realisations being well approximated by a linear power spectrum. This provides proof of principle that complex inflationary physics can give rise to simple emergent power spectra. We explain how these results can be understood in terms of large N f universality of random matrix theory.
Loop quantum cosmology: from pre-inflationary dynamics to observations
International Nuclear Information System (INIS)
Ashtekar, Abhay; Barrau, Aurélien
2015-01-01
The Planck collaboration has provided us rich information about the early Universe, and a host of new observational missions will soon shed further light on the ‘anomalies’ that appear to exist on the largest angular scales. From a quantum gravity perspective, it is natural to inquire if one can trace back the origin of such puzzling features to Planck scale physics. Loop quantum cosmology provides a promising avenue to explore this issue because of its natural resolution of the big bang singularity. Thanks to advances over the last decade, the theory has matured sufficiently to allow concrete calculations of the phenomenological consequences of its pre-inflationary dynamics. In this article we summarize the current status of the ensuing two-way dialog between quantum gravity and observations. (paper)
Inflationary magnetogenesis and non-local actions: the conformal anomaly
Energy Technology Data Exchange (ETDEWEB)
El-Menoufi, Basem Kamal, E-mail: bmahmoud@physics.umass.edu [Department of Physics, University of Massachusetts Amherst, MA 01003 (United States)
2016-02-01
We discuss the possibility of successful magnetogenesis during inflation by employing the one-loop effective action of massless QED. The action is strictly non-local and results from the long distance fluctuations of massless charged particles present at the inflationary scale. Most importantly, it encodes the conformal anomaly of QED which is crucial to avoid the vacuum preservation in classical electromagnetism. In particular, we find a blue spectrum for the magnetic field with spectral index n{sub B} ≅ 2 − α{sub e} where α{sub e} depends on both the number of e-folds during inflation as well as the coefficient of the one-loop beta function. In particular, the sign of the beta function has important bearing on the final result. A low reheating temperature is required for the present day magnetic field to be consistent with the lower bound inferred on the field in the intergalactic medium.
Inflationary susceptibilities, duality and large-scale magnetic fields generation
Giovannini, Massimo
2013-01-01
We investigate what can be said about the interaction of scalar fields with Abelian gauge fields during a quasi-de Sitter phase of expansion and under the assumption that the electric and the magnetic susceptibilities do not coincide. The duality symmetry, transforming the magnetic susceptibility into the inverse of the electric susceptibility, exchanges the magnetic and electric power spectra. The mismatch between the two susceptibilities determines an effective refractive index affecting the evolution of the canonical fields. The constraints imposed by the duration of the inflationary phase and by the magnetogenesis requirements pin down the rate of variation of the susceptibilities that is consistent with the observations of the magnetic field strength over astrophysical and cosmological scales but avoids back-reaction problems. The parameter space of this magnetogenesis scenario is wider than in the case when the susceptibilities are equal, as it happens when the inflaton or some other spectator field is ...
Inflationary perturbations in anisotropic, shear-free universes
International Nuclear Information System (INIS)
Pereira, Thiago S.; Carneiro, Saulo; Marugan, Guillermo A. Mena
2012-01-01
In this work, the linear and gauge-invariant theory of cosmological perturbations in a class of anisotropic and shear-free spacetimes is developed. After constructing an explicit set of complete eigenfunctions in terms of which perturbations can be expanded, we identify the effective degrees of freedom during a generic slow-roll inflationary phase. These correspond to the anisotropic equivalent of the standard Mukhanov-Sasaki variables. The associated equations of motion present a remarkable resemblance to those found in perturbed Friedmann-Robertson-Walker spacetimes with curvature, apart from the spectrum of the Laplacian, which exhibits the characteristic frequencies of the underlying geometry. In particular, it is found that the perturbations cannot develop arbitrarily large super-Hubble modes
Grassmann expansion of the classical N=2 supergravity field equations
International Nuclear Information System (INIS)
Embacher, F.
1984-01-01
The classical field equations of N=2 supergravity are expanded with respect to an infinite dimensional Grassmann algebra. The general freedom in constructing classical solution is exhibited. As an application, a uniqueness theorem for supersymmetric extreme black holes is given. (Author)
Supersymmetric black holes in N = 2 supergravity theory
International Nuclear Information System (INIS)
Aichelburg, P.C.
1982-01-01
We present an exact, asymptotically flat, stationary solution of the field equations of O(2) extended supergravity theory. This solution has a mass, central electric charge as well as a supercharge and constitutes the first exact, supersymmetric generalization of the black hole geometries. The solution generalizes the extreme Reissner-Nordstroem black holes. (Author)
Half-supersymmetric solutions in five-dimensional supergravity
International Nuclear Information System (INIS)
Gutowski, Jan B.; Sabra, Wafic
2007-01-01
We present a systematic classification of half-supersymmetric solutions of gauged N = 2, D = 5 supergravity coupled to an arbitrary number of abelian vector multiplets for which at least one of the Killing spinors generate a time-like Killing vector
General supersymmetric solutions of five-dimensional supergravity
International Nuclear Information System (INIS)
Gutowski, Jan B.; Sabra, Wafic
2005-01-01
The classification of 1/4-supersymmetric solutions of five dimensional gauged supergravity coupled to arbitrary many abelian vector multiplets, which was initiated elsewhere, is completed. The structure of all solutions for which the Killing vector constructed from the Killing spinor is null is investigated in both the gauged and the ungauged theories and some new solutions are constructed
Well-posedness of (N = 1) classical supergravity
International Nuclear Information System (INIS)
Bao, D.; Choquet-Bruhat, Y.; Isenberg, J.; Yasskin, P.B.
1985-01-01
In this paper we investigate whether classical (N = 1) supergravity has a well-posed locally causal Cauchy problem. We define well-posedness to mean that any choice of initial data (from an appropriate function space) which satisfies the supergravity constraint equations and a set of gauge conditions can be continuously developed into a space-time solution of the supergravity field equations around the initial surface. Local causality means that the domains of dependence of the evolution equations coincide with those determined by the light cones. We show that when the fields of classical supergravity are treated as formal objects, the field equations are (under certain gauge conditions) equivalent to a coupled system of quasilinear nondiagonal second-order partial differential equations which is formally nonstrictly hyperbolic (in the sense of Leray--Ohya). Hence, if the fields were numerical valued, there would be an applicable existence theorem leading to well-posedness. We shall observe that well-posedness is assured if the fields are taken to be Grassmann (i.e., exterior algebra) valued, for then the second-order system decouples into the vacuum Einstein equation and a sequence of numerical valued linear diagonal strictly hyperbolic partial differential equations which can be solved successively
Chaotic inflation in supergravity after Planck and BICEP2
International Nuclear Information System (INIS)
Kallosh, Renata; Linde, Andrei
2014-05-01
We discuss the general structure and observational consequences of some of the simplest versions of chaotic inflation in supergravity in relation to the data by Planck 2013 and BICEP2. We show that minimal modifications to the simplest quadratic potential are sufficient to provide a controllable tensor mode signal and a suppression of CMB power at large angular scales.
N=2 supergravity in superspace: the invariant action
International Nuclear Information System (INIS)
Gal'perin, A.S.; Sokachev, E.
1987-01-01
This paper continues the formulation of harmonic superspace supergravity. We write down the invariant action for the first off-shell version of the theory. The proof of the invariance relies on the existence of a new 'hybrid' basis in harmonic superspace in which semi-chirality combined with analyticity are manifest