English
Related papers

Related papers: New Classes of Off-Diagonal Cosmological Solutions…

200 papers

Density linear perturbations in Einstein-Cartan two fluid cosmologies where the outer model is an isotropic Friedmann solution with closed model while the inner model is a flat anisotropic Einstein-Cartan (EC) cosmology with shear are…

Astrophysics · Physics 2007-05-23 L. C. Garcia de Andrade

We construct a new class of exact solutions describing spacetimes possessing Lie algebroid symmetry. They are described by generic off-diagaonal 5D metrics embedded in bosonic string gravity and possess nontrivial limits to the Einstein…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sergiu I. Vacaru

We present a new class of solutions in odd dimensions to Einstein's equations containing either a positive or negative cosmological constant. These solutions resemble the even-dimensional Eguchi-Hanson--(anti)-de Sitter ((A)dS) metrics,…

High Energy Physics - Theory · Physics 2008-11-26 R. Clarkson , R. B. Mann

This paper presents solutions to Einstein's equation -- and the numerical methods used to construct them -- that describe simple cosmological models on manifolds with compact non-orientable spatial slices. These solutions have been…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Fan Zhang , Lee Lindblom

Near the singularity, gravity should be modified to an effective theory, in the same sense as with the Euler-Heisenberg electrodynamics. This effective gravity surmounts to higher derivative theory, and as is well known, a much more reacher…

General Relativity and Quantum Cosmology · Physics 2013-08-02 Daniel Müller

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.…

General Physics · Physics 2012-11-15 Anirudh Pradhan , Ajay Kumar Singh , H. Amirhashchi

We apply a new general method of anholonomic frames with associated nonlinear connection structure to construct new classes of exact solutions of Einstein-Dirac equations in five dimensional (5D)gravity. Such solutions are parametrized by…

High Energy Physics - Theory · Physics 2009-11-07 Sergiu I. Vacaru , Florian Catalin Popa

A new framework to perturbative quantum gravity is proposed following the geometry of nonholonomic distributions on (pseudo) Riemannian manifolds. There are considered such distributions and adapted connections, also completely defined by a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Sergiu I. Vacaru

We initiate a non-perturbative study of anisotropic, non-conformal and confining gauge theories that are holographically realized in gravity by generic Einstein-Axion-Dilaton systems. In the vacuum our solutions describe RG flows from a…

High Energy Physics - Theory · Physics 2018-09-25 Dimitrios Giataganas , Umut Gürsoy , Juan F. Pedraza

In the context of the Minimal Geometric Deformation method, in this paper we implement the inverse problem in a black hole scenario. In order to deal with an anisotropic polytropic black hole solution of the Einstein field equations with…

General Relativity and Quantum Cosmology · Physics 2018-12-04 Ernesto Contreras , Pedro Bargueño

We establish a deformation framework for highly symmetric solutions to the Einstein equations. In this framework, four-dimensional metrics are constructed from three-dimensional {\eta}-Einstein metrics admitting a deformation determined by…

General Relativity and Quantum Cosmology · Physics 2026-04-23 Hiroshi Kozaki , Satsuki Matsuno , Tatsuhiko Koike , Yoshiyuki Morisawa , Hideki Ishihara

The gravitational equations of the three dimensional (3D) brane world are investigated for both off-diagonal and warped 5D metrics which can be diagonalized with respect to some anholonomic frames when the gravitational and matter fields…

High Energy Physics - Phenomenology · Physics 2007-05-23 Sergiu I. Vacaru

In $D$-dimensional dilaton gravitational model with the central charge deficit the generalized Friedmann-type cosmological solutions (spatially homogeneous and isotropic) are obtained and classified.

High Energy Physics - Theory · Physics 2007-05-23 G. S. Sharov , E. G. Vorontsova

The book contains a collection of works on Riemann-Cartan and metric-affine manifolds provided with nonlinear connection structure and on generalized Finsler-Lagrange and Cartan-Hamilton geometries and Clifford structures modelled on such…

General Relativity and Quantum Cosmology · Physics 2014-11-17 S. Vacaru , P. Stavrinos , E. Gaburov , D. Gonţa

The (n +1)-dimensional Einstein-Gauss-Bonnet (EGB) model is considered. For diagonal cosmological metrics, the equations of motion are written as a set of Lagrange equations with the effective Lagrangian containing two "minisuperspace"…

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

By using anholonomic frames in (pseudo) Riemannian spaces we define anisotropic extensions of Euclidean Taub-NUT spaces. With respect to coordinate frames such spaces are described by off-diagonal metrics which could be diagonalized by…

High Energy Physics - Theory · Physics 2009-11-07 Sergiu I. Vacaru , Ovidiu Tintareanu-Mircea

In the scope of the nonlinear massive gravity, we study fixed points of evolution equations for a Bianchi type--I universe. We find a new attractor solution with non-vanishing anisotropy, on which the physical metric is isotropic but the…

High Energy Physics - Theory · Physics 2012-10-17 A. Emir Gumrukcuoglu , Chunshan Lin , Shinji Mukohyama

The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein's general relativity could alleviate the different problems associated with it that result…

General Relativity and Quantum Cosmology · Physics 2022-10-14 The FADE Collaboration , Heliudson Bernardo , Benjamin Bose , Guilherme Franzmann , Steffen Hagstotz , Yutong He , Aliki Litsa , Florian Niedermann

Advantages of inhomogeneous cosmological models that are exact solutions of Einstein's equations over linearised perturbations of homogeneous models are presented. Examples of effects that can be described in the inhomogeneous ones are…

General Relativity and Quantum Cosmology · Physics 2011-12-05 Andrzej Krasiński

This work investigates alternative theories of gravity, the solutions to their field equations and the constraints that can be imposed upon them from observation and experiment. Specifically, we consider the cosmologies and spherically…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Clifton