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In this paper we construct new solutions of the Einstein-Gauss-Bonnet field equations in an isotropic Shiromizu-Maeda-Sasaki brane-world setting which represent a couple of $Z_2$-symmetric vacuum thin shells splitting from the central…

General Relativity and Quantum Cosmology · Physics 2018-03-26 Marcos A. Ramirez

We find an explicit cosmological model which allows a special type of cosmological singularity which we call a $w$-singularity. This singularity has the scale factor finite, the energy density and pressure vanishing, and the only singular…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Mariusz P. Dabrowski , Tomasz Denkiewicz

Homogeneous cosmology in the braneworld can be studied without solving bulk equations of motion explicitly. The reason is simply because the symmetry of the spacetime restricts possible corrections in the 4-dimensional effective equations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jiro Soda , Sugumi Kanno

A closed mathematical model of the statistical self-gravitating system of scalar charged particles for conformal invariant scalar interactions is constructed on the basis of relativistic kinetics and gravitation theory. Asymptotic…

General Relativity and Quantum Cosmology · Physics 2015-08-13 Yurii Ignat'ev

Cosmography is a useful tool to constrain cosmological models, in particular dark energy models. In the case of modified theories of gravity, where the equations of motion are generally quite complicated, cosmography can contribute to…

General Relativity and Quantum Cosmology · Physics 2010-12-23 Mariam Bouhmadi-Lopez , Salvatore Capozziello , Vincenzo F. Cardone

Models of inflationary cosmology admit a choice of the metric for which the geometry of homogeneous isotropic solutions becomes flat Minkowski space in the infinite past. In this primordial flat frame all mass scales vanish in the infinite…

General Relativity and Quantum Cosmology · Physics 2021-10-27 C. Wetterich

Measurements of CMB anisotropy and, more recently, polarization have played a very important role allowing precise determination of various parameters of the `standard' cosmological model. The expectation of the paradigm of inflation and…

Astrophysics · Physics 2008-11-26 Tarun Souradeep

We present a class of graviton-dilaton models which leads to a singularity free evolution of the universe. We study the evolution of a homogeneous isotropic universe. We follow an approach which enables us to analyse the evolution and…

High Energy Physics - Theory · Physics 2011-09-09 S. Kalyana Rama

The general solution of Einstein's gravity equation in $D$ dimensions for an anisotropic and spherically symmetric matter distribution is calculated in a bulk with position dependent cosmological constant. Results for $n$ concentric…

General Relativity and Quantum Cosmology · Physics 2013-03-01 I. C. Jardim , R. R. Landim , G. Alencar , R. N. Costa Filho

We consider a variant of the brane-world model in which the universe is the direct product of a Friedmann, Robertson-Walker (FRW) space and a compact hyperbolic manifold of dimension $d\geq2$. Cosmology in this space is particularly…

High Energy Physics - Theory · Physics 2009-10-31 Glenn D. Starkman , Dejan Stojkovic , Mark Trodden

We discuss the cosmological evolution of a braneworld in five dimensional Gauss-Bonnet gravity. Our discussion allows the fifth (bulk) dimension to be space-like as well as time-like. The resulting equations of motion have the form of a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Hideki Maeda , Varun Sahni , Yuri Shtanov

The evolution of a probe D-brane in the p-brane background has been considered. The anisotropic evolution of the world-volume of the D-brane with a given topology of a world-volume in a form of a direct product of a n-dimensional flat space…

High Energy Physics - Theory · Physics 2017-06-27 Pawel Gusin

A cosmological model for the early time Universe is proposed. In this model, the Universe is a wandering brane moving in a warped throat of a Calabi-Yau space. A non-zero angular momentum induces a turning point in the brane trajectory, and…

High Energy Physics - Theory · Physics 2009-08-13 Cristiano Germani , N. E. Grandi , Alex Kehagias

In cosmology an important role is played by homogeneous and isotropic solutions of the Einstein-Euler equations and linearized perturbations of these. This paper proves results on the asymptotic behaviour of scalar perturbations both in the…

Analysis of PDEs · Mathematics 2009-06-16 Paul T. Allen , Alan D. Rendall

Anisotropic generalization of Randall and Sundrum brane-world model is considered. A new class of exact solutions for brane and bulk geometry is found; it is related to anisotropic Kasner solution. In view of this, the old question of…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Andrei V. Frolov

Observational Cosmology has indeed made very rapid progress in the past decade. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation Measurements of CMB anisotropy and,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Tarun Souradeep

In the Cosmological Slingshot Scenario, our Universe is a D3-brane that extends in the 4d noncompact directions of a warped Calabi-Yau compactification of IIB Supergravity. Early time cosmology corresponds to a period in which the brane…

High Energy Physics - Theory · Physics 2009-08-13 Cristiano Germani , Nicolas Grandi , Alex Kehagias

Recent progress has revealed a number of constraints that cosmological correlators and the closely related field-theoretic wavefunction must obey as a consequence of unitarity, locality, causality and the choice of initial state. When…

High Energy Physics - Theory · Physics 2024-03-20 Carlos Duaso Pueyo , Enrico Pajer

We consider the problem of the initial conditions and behaviour of the perturbations in scalar field cosmology with general potential. We use the general definition of adiabatic and isocurvature conditions to set the appropriate initial…

Astrophysics · Physics 2009-10-31 Francesca Perrotta , Carlo Baccigalupi

A primordial inflationary phase allows one to erase any possible anisotropic expansion thanks to the cosmic no-hair theorem. If there is no global anisotropic stress, then the anisotropic expansion rate tends to decrease. What are the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-04 Thiago S. Pereira , Cyril Pitrou
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