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A cosmological model describing the evolution of $n$ Einstein spaces $(n>1)$ with $m$-component perfect-fluid matter is considered. When all spaces are Ricci-flat and for any $\alpha$-th component the pressures in all spaces are…

General Relativity and Quantum Cosmology · Physics 2011-04-20 V. D. Ivashchuk , V. N. Melnikov

D-dimensional cosmological model describing the evolution of a perfect fluid with negative pressure (x-fluid) and a fluid possessing both shear and bulk viscosity in n Ricci-flat spaces is investigated. The second equations of state are…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. R. Gavrilov , V. N. Melnikov

A multidimensional cosmological model describing the dynamics of n+1 Ricci-flat factor-spaces M_i in the presence of a one-component anisotropic fluid is considered. The pressures in all spaces are proportional to the density: p_i = w_i…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. -M. Alimi , V. D. Ivashchuk , S. A. Kononogov , V. N. Melnikov

Multidimensional cosmological model describing the evolution of a fluid with shear and bulk viscosity in $n$ Ricci-flat spaces is investigated. The barotropic equation of state for the density and the pressure in each space is assumed. The…

General Relativity and Quantum Cosmology · Physics 2010-04-30 V. R. Gavrilov , V. N. Melnikov , Roland Triay

We consider anisotropic cosmological models with an universe of dimension 4 or more, factorized into n>1 Ricci-flat spaces, containing an m-component perfect fluid of m non-interacting homogeneous minimally coupled scalar fields under…

General Relativity and Quantum Cosmology · Physics 2015-06-25 U. Kasper , M. Rainer , A. Zhuk

Exact solutions with an exponential behaviour of the scale factors are considered in a multidimensional cosmological model describing the dynamics of n+1 Ricci-flat factor spaces M_i in the presence of a one-component perfect fluid. The…

High Energy Physics - Theory · Physics 2008-11-26 V. D. Ivashchuk , S. A. Kononogov , V. N. Melnikov , M. Novello

The D-dimensional cosmological model on the manifold $M = R \times M_{1} \times M_{2}$ describing the evolution of 2 Einsteinian factor spaces, $M_1$ and $M_2$, in the presence of multicomponent perfect fluid source is considered. The…

General Relativity and Quantum Cosmology · Physics 2009-10-31 V. R. Gavrilov , V. N. Melnikov

A cosmological model describing the evolution of n Ricci-flat spaces (n>1) in the presence of 1-component perfect-fluid and minimally coupled scalar field is considered. When the pressures in all spaces are proportional to the density, the…

High Energy Physics - Theory · Physics 2009-09-25 V. D. Ivashchuk , V. N. Melnikov

Multidimensional cosmological models in the presence of a bare cosmological constant and a perfect fluid are investigated under dimensional reduction to 4-dimensional effective models. Stable compactification of the internal spaces is…

General Relativity and Quantum Cosmology · Physics 2009-10-31 U. Guenther , A. Zhuk

Self-similar, spherically symmetric cosmological models with a perfect fluid and a scalar field with an exponential potential are investigated. New variables are defined which lead to a compact state space, and dynamical systems methods are…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Alan Coley , Martin Goliath

In this paper we performed investigation of the spatially-flat cosmological models whose spatial section is product of three- ("our Universe") and extra-dimensional parts. The matter source chosen to be the perfect fluid which exists in the…

General Relativity and Quantum Cosmology · Physics 2019-02-11 Sergey A. Pavluchenko

We consider a D-dimensional cosmological model describing an evolution of Ricci-flat factor spaces, M_1,...M_n (n > 2), in the presence of an m-component perfect fluid source (n > m > 1). We find characteristic vectors, related to the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 U. Kasper , V. R. Gavrilov , V. N. Melnikov , M. Rainer

A five-dimensional cosmological model including a single perfect fluid is studied in the framework of dynamical system analysis. All the critical points of the system with their stability properties are listed and some representative phase…

General Relativity and Quantum Cosmology · Physics 2020-02-17 A. Savaş Arapoğlu , Ezgi Canay , A. Emrah Yükselci

We consider multidimensional cosmologies in even-dimensional space-times (D=2n) containg perfect fluid and a multidimensional generalization of the Maxwell field, preserving its conformal invariance (the F field, an n-form). Among models…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kirill A. Bronnikov

We consider the Bianchi I geometry coupled to several species of comoving barotropic perfect fluids with a linear equation of state in the context of general relativity. The solution of the dynamics can be reduced to a quadrature, which can…

General Relativity and Quantum Cosmology · Physics 2024-10-29 David Brizuela , Sara F. Uria

The integration procedure for multidimensional cosmological models with multicomponent perfect fluid in spaces of constant curvature is developed. Reduction of pseudo-Euclidean Toda-like systems to the Euclidean ones is done. Some known…

General Relativity and Quantum Cosmology · Physics 2015-06-25 V. R. Gavrilov , V. D. Ivashchuk , V. N. Melnikov

The article is devoted to cosmology. It deals with homogeneous anisotropic cosmological models. Scale factors have been evaluated for the multicomponent models with perfect fluid, taking account of its expansion, rotation and shear. The…

General Relativity and Quantum Cosmology · Physics 2019-06-10 K. K. Ernazarov

In this paper we study the evolution of spatially homogeneous and anisotropic Bianchi type-I Universe models with the cosmological constant, \Lambda, and filled with nonlinear viscous fluid. The dynamical equations for these models are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nouraddin Mostafapoor , Oyvind Gron

We investigated a flat multidimensional cosmological model in Gauss-Bonnet gravity in presence of a matter in form of perfect fluid. We found analytically new stationary regimes (these results are valid for arbitrary number of spatial…

General Relativity and Quantum Cosmology · Physics 2015-03-13 I. V. Kirnos , S. A. Pavluchenko , A. V. Toporensky

In the present work, we study the dynamical evolution of an homogeneous and anisotropic, noncommutative (NC) Bianchi I (BI) model coupled to a radiation perfect fluid. Our first motivation is determining if the present model tends to an…

General Relativity and Quantum Cosmology · Physics 2024-03-07 G. Oliveira-Neto , T. M. Abreu
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