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In this paper we perform a systematic study of spatially flat [(3+D)+1]-dimensional Einstein-Gauss-Bonnet cosmological models with $\Lambda$-term. We consider models that topologically are the product of two flat isotropic subspaces with…

High Energy Physics - Theory · Physics 2016-10-19 Sergey A. Pavluchenko

Solutions to flat space Friedmann-Robertson-Walker cosmologies in Brans-Dicke theory with a cosmological constant are investigated. The matter is modelled as a $\gamma$-law perfect fluid. The field equations are reduced from fourth order to…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Shawn J. Kolitch

The common assertion that the Ricci flows of Einstein spaces with cosmological constant can be modelled by certain classes of nonholonomic frame, metric and linear connection deformations resulting in nonhomogeneous Einstein spaces is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergiu I. Vacaru , Mihai Visinescu

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

Self-similarity in general relativity is briefly reviewed and the differences between self-similarity of the first kind and generalized self-similarity are discussed. The covariant notion of a kinematic self-similarity in the context of…

General Relativity and Quantum Cosmology · Physics 2009-10-28 A. A. Coley

The field equations derived from the low energy string effective action with a matter tensor describing a perfect fluid with a barotropic equation of state are solved iteratively using the long-wavelength approximation, i.e. the field…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Piret Kuusk , Margus Saal

We study the system of equations which describes barotropic (isentropic) flows of viscous compressible multi-fluids (mixtures of fluids). We study the relations between pressure, densities, concentrations, viscosities and other parameters…

Analysis of PDEs · Mathematics 2017-11-22 Alexander Mamontov , Dmitriy Prokudin

In this paper we investigate the constant volume exponential solutions (i.e. the solutions with the scale factors change exponentially over time so that the comoving volume remains the same) in the Einstein-Gauss-Bonnet gravity. We find…

General Relativity and Quantum Cosmology · Physics 2014-12-17 Dmitry Chirkov , Sergey A. Pavluchenko , Alexey Toporensky

The present work deals with evolution of the fractal model of the Universe in the background of homogeneous and isotropic FLRW space--time geometry. The cosmic substrum is taken as perfect fluid with barotropic equation of state. A general…

General Physics · Physics 2018-11-27 Dipanjana Das , Sourav Dutta , Abdulla Al Mamon , Subenoy Chakraborty

We present exact solutions of the gravitational field equations in the generalized Randall-Sundrum model for an anisotropic brane with Bianchi type I and V geometry, with perfect fluid and scalar fields as matter sources. Under the…

High Energy Physics - Theory · Physics 2009-11-07 Chiang-Mei Chen , T. Harko , M. K. Mak

The dynamics and evolution of Bianchi type I space-times is considered in the framework of the four-dimensional truncation of a reduced theory obtained from the N=2,D=5 supergravity. The general solution of the gravitational field equations…

High Energy Physics - Theory · Physics 2009-10-31 Chiang-Mei Chen , T. Harko , M. K. Mak

The authors study the Cauchy problem of the magnetohydrodynamic equations for viscous compressible barotropic flows in two or three spatial dimensions with vacuum as far field density. For two spatial dimensions, we establish the global…

Analysis of PDEs · Mathematics 2014-05-21 Boqiang Lv , Xiaoding Shi , Xinying Xu

In this paper we perform a systematic study of vacuum spatially flat ((3+D)+1)-dimensional Einstein-Gauss-Bonnet cosmological models. We consider models which topologically are the product of two flat isotropic subspaces with different…

High Energy Physics - Theory · Physics 2016-07-26 Sergey A. Pavluchenko

We study the cosmological dynamics of non-minimally coupled matter models using the Brown's variational approach to relativistic fluids in General Relativity. After decomposing the Ricci scalar into a bulk and a boundary term, we construct…

General Relativity and Quantum Cosmology · Physics 2025-12-22 Hala A. Ashi , Christian G. Boehmer , Antonio d'Alfonso del Sordo , Erik Jensko

New exact solutions of relativistic perfect fluid hydrodynamics are described, including the first family of exact rotating solutions. The method used to search for them is an investigation of the relativistic hydrodynamical equations and…

Nuclear Theory · Physics 2011-05-13 M. I. Nagy

Einstein's field equations for spatially self-similar spherically symmetric perfect-fluid models are investigated. The field equations are rewritten as a first-order system of autonomous differential equations. Dimensionless variables are…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Martin Goliath , Ulf S Nilsson , Claes Uggla

Using the 3+1 formalism of general relativity we obtain the equations governing the dynamics of spherically symmetric spacetimes with arbitrary sources. We then specialize for the case of perfect fluids accompanied by a flow of interacting…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Marcelo Salgado

In this paper we present the noncommutative Bianchi Class A cosmological models coupled to barotropic perfect fluid. The commutative and noncommutative quantum solution to the Wheeler-DeWitt equation for any factor ordering, to the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Aguero , J. A. Aguilar S. , C. Ortiz , M. Sabido , J. Socorro

We consider the evolution of perturbed cosmological spacetime with multiple fluids and fields in Einstein gravity. Equations are presented in gauge-ready forms, and are presented in various forms using the curvature (\Phi or \phi_\chi) and…

Astrophysics · Physics 2010-05-28 J. Hwang , H. Noh

We investigate a class of cosmological solutions of Einstein's field equations in higher dimensions with a cosmological constant and an ideal fluid matter distribution as a source. We discuss the dynamical evolution of the universe subject…

General Relativity and Quantum Cosmology · Physics 2013-02-15 Ozgur Akarsu , Tekin Dereli