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Related papers: Exact Solutions in Locally Anisotropic Gravity and…

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In this work, we apply the anholonomic deformation method for constructing new classes of anisotropic cosmological solutions in Einstein gravity and/or generalizations with nonholonomic variables. There are analyzed four types of, in…

Mathematical Physics · Physics 2015-05-18 Sergiu I. Vacaru

We numerically investigate limits of a two-parameter family of stationary solutions to the Einstein-Vlasov system. The solutions are toroidal and have non-vanishing angular momentum. As one tunes to more relativistic solutions (measured for…

General Relativity and Quantum Cosmology · Physics 2019-01-16 Ellery Ames , Håkan Andréasson , Anders Logg

We extend the derivation of mass formulas for stationary axisymmetric asymptotically locally flat solutions with string singularities on the polar axis to general supergravity actions containing vector and scalar fields. It is based on the…

General Relativity and Quantum Cosmology · Physics 2024-05-30 Igor Bogush , Dmitri Gal'tsov , Gérard Clément

We study black holes with linear equation of state within the framework of asymptotically safe gravity. This study extends previous work on gravitational collapse in asymptotically safe gravity (that has been done for a dust fluid) by…

General Relativity and Quantum Cosmology · Physics 2026-02-17 Ramin Hassannejad , Fatimah Shojai , Kazuharu Bamba

We review the geometric setting of the field theory with locally anisotropic interactions. The concept of locally anisotropic space is introduced as a general one for various type of extensions of Lagrange and Finsler geometry and higher…

dg-ga · Mathematics 2008-02-03 Sergiu I. Vacaru

This brief report presents analytical solutions to the equations of motion of a null string. The background spacetime is a magnetically charged Kaluza-Klein black hole. The string coordinates are expanded with the world-sheet velocity of…

High Energy Physics - Theory · Physics 2009-10-31 H. K. Jassal , A. Mukherjee

We find the general behaviour of homogeneous and isotropic cosmological models in some fourth-order theories of gravity. Explicit, exact, general solutions are given for both empty universes and those filled with a perfect fluid. For the…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Timothy Clifton

A new method of construction of integral varieties of Einstein equations in three dimensional (3D) and 4D gravity is presented whereby, under corresponding redefinition of physical values with respect to anholonomic frames of reference with…

General Relativity and Quantum Cosmology · Physics 2010-02-03 Sergiu I. Vacaru

We obtain an exact solution of Einstein's equations for a charged, static and spherically symmetric body, surrounded by a fluid of strings and with a cosmological constant. This corresponds to the Reissner-Nordstr\"om (de Sitter)-Anti de…

General Relativity and Quantum Cosmology · Physics 2020-12-30 J. M. Toledo , V. B. Bezerra

We present several classes of exact solutions in the Einstein-Klein-Gordon system with a cosmological constant. The spacetime has spherical, plane, or hyperbolic symmetry and the higher-dimensional solutions are obtained in a closed form…

General Relativity and Quantum Cosmology · Physics 2013-02-15 Hideki Maeda

This paper explores the Friedmann field equations within the framework of Lovelock gravity, a natural extension of Einstein's gravity, focusing on both flat and open universes. Utilizing an approach based on independent Riemann tensor…

General Relativity and Quantum Cosmology · Physics 2024-12-30 Aleksei Nikolaev

We find U(1)_{E} \times U(1)_{M} non-extremal black hole solutions of 6-dimensional Kaluza-Klein supergravity theories. Extremal solutions were found by Cveti\v{c} and Youm\cite{C-Y}. Multi black hole solutions are also presented. After…

High Energy Physics - Theory · Physics 2010-11-01 Jaemo Park

A generalized model of space-time is given, taking into consideration the anisotropic structure of fields which are depended on the position and the direction (velocity).In this framework a generalized FRW-metric the Raychaudhouri and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 P. C. Stavrinos , A. P. Kouretsis , M. Stathakopoulos

Theoretical considerations of fundamental physics, as well as certain cosmological observations, persistently point out to permissibility, and maybe necessity, of macroscopic modifications of the Einstein general relativity. The…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Stanislav V. Babak , L. P. Grishchuk

We consider the action principles that are the lower dimensional limits of the Einstein-Gauss-Bonnet gravity {\it via} the Kaluza-Klein route. We study the vacua and obtain some exact solutions. We find that the reality condition of the…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Liang Ma , H. Lu

Recent nonlinear completions of Fierz-Pauli theory for a massive spin-2 field include nonlinear massive gravity and bimetric theories. The spectrum of black-hole solutions in these theories is rich, and comprises the same vacuum solutions…

General Relativity and Quantum Cosmology · Physics 2013-08-26 Richard Brito , Vitor Cardoso , Paolo Pani

Anisotropic exponential cosmological solutions for a space of arbitrary dimension filled with ordinary matter in the 4th and 5th orders of Lovelock gravity are obtained. Also we have supposed a generalization of such solutions on an…

General Relativity and Quantum Cosmology · Physics 2017-02-24 Ilya V. Kirnos

It has been noticed that the k-string observables can be expressed in terms of the fundamental string ones. We identify a sufficient condition for a generic gravity dual background which when satisfied the mapping can be done. The condition…

High Energy Physics - Theory · Physics 2015-04-01 Dimitrios Giataganas

We review analytical solutions of the Einstein equations which are expressed in terms of elementary functions and describe Friedmann-Lema\^itre-Robertson-Walker universes sourced by multiple (real or effective) perfect fluids with constant…

General Relativity and Quantum Cosmology · Physics 2021-12-15 Valerio Faraoni , Sonia Jose , Steve Dussault

A general class of gravitational models driven by a nonlocal scalar field with a linear or quadratic potential is considered. We study the action with an arbitrary analytic function $F(\Box)$, which has both simple and double roots. The way…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Sergey Yu. Vernov
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