English
Related papers

Related papers: Exact Solutions in Locally Anisotropic Gravity and…

200 papers

A general class of cosmological models driven by a nonlocal scalar field inspired by the string field theory is studied. Using the fact that the considering linear nonlocal model is equivalent to an infinite number of local models we have…

High Energy Physics - Theory · Physics 2008-11-26 I. Ya. Aref'eva , L. V. Joukovskaya , S. Yu. Vernov

We construct exact solutions representing a Friedmann-Lema\^itre-Robsertson-Walker (FLRW) universe in a generalized hybrid metric-Palatini theory. By writing the gravitational action in a scalar-tensor representation, the new solutions are…

General Relativity and Quantum Cosmology · Physics 2017-07-18 João L. Rosa , Sante Carloni , José P. S. Lemos , Francisco S. N. Lobo

The conformal gravity remarkably boosts our prehension of gravity theories. We find a series of dynamical solutions in the $W^2$-conformal gravity, including generalized Schwarzschild-Friedmann-Robertson-Walker (GSFRW), charged generalized…

General Relativity and Quantum Cosmology · Physics 2017-06-28 Hongsheng Zhang , Yi Zhang , Xin-Zhou Li

This paper revisits black hole solutions surrounded by clouds and fluids of strings within the framework of general relativity. We introduce a generalized equation of state for a fluid of strings with a variable parameter and derive a…

General Relativity and Quantum Cosmology · Physics 2025-02-25 Luis Cesar Nunes dos Santos

The dynamics of the early universe may have been profoundly influenced by spatial anisotropies. A search for such backgrounds in the context of string cosmology has uncovered the existence of an entire class of (spatatially) homogeneous but…

High Energy Physics - Theory · Physics 2016-09-06 N. A. Batakis , A. A. Kehagias

Einstein gravity at $D\rightarrow 2$ limit can be obtained from the Kaluza-Klein procedure by taking the dimensions of the internal space to zero while keeping only the breathing mode. The resulting scalar-tensor theory can be further…

High Energy Physics - Theory · Physics 2023-03-29 Qi-Yuan Mao , H. Lu

We present an introduction to the geometry of higher order vector and co-vector bundles (including higher order generalizations of the Finsler geometry and Kaluza--Klein gravity) and review the basic results on Clifford and spinor…

Differential Geometry · Mathematics 2007-05-23 Sergiu I. Vacaru , Nadejda A. Vicol

We study brane worlds in an anisotropic higher-dimensional spacetime within the context of $f(R)$ gravity. Firstly, we demonstrate that this spacetime with a concrete metric ansatz is stable against linear tensor perturbations under certain…

High Energy Physics - Theory · Physics 2020-12-22 Zheng-Quan Cui , Zi-Chao Lin , Jun-Jie Wan , Yu-Xiao Liu , Li Zhao

Three-dimensional Einstein gravity coupled to zero, one and two forms is solved in terms of a polyhomogeneous asymptotic expansion, generalising stationary black string solutions. From first order terms we obtain, in closed form, a new…

High Energy Physics - Theory · Physics 2019-09-04 Philippe Spindel

We show how the classical string dynamics in $D$-dimensional gravity background can be reduced to the dynamics of a massless particle constrained on a certain surface whenever there exists at least one Killing vector for the background…

High Energy Physics - Theory · Physics 2009-11-07 P. Bozhilov

In this research manuscript, we explore cylindrically symmetric solutions within the framework of modified $f(R)$ theories of gravity, where $R$ representing the Ricci scalar. The study focuses on analyzing the cylindrical solutions within…

General Relativity and Quantum Cosmology · Physics 2024-04-18 Adnan Malik

We consider exact solutions of Einstein equations defining static black holes parametrized by off-diagonal metrics which by anholonomic mappings can be equivalently transformed into some diagonal metrics with coefficients being very similar…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru , Evghenii Gaburov

We examine strictly static asymptotically flat spacetimes in Einstein-Gauss-Bonnet gravity with U(1) gauge field, revealing that, up to small curvature corrections, confomally flat slices of the spacetime in question are of Minkowski…

High Energy Physics - Theory · Physics 2016-01-26 Marek Rogatko

A toy model of Einstein gravity with a Gauss-Bonnet classically "entropic" term mimicking a quantum correction is considered. The static black hole solution due to Tomozawa is found and generalized with the inclusion of non trivial horizon…

General Relativity and Quantum Cosmology · Physics 2013-10-15 Guido Cognola , Ratbay Myrzakulov , Lorenzo Sebastiani , Sergio Zerbini

We present an introduction to the geometry of higher order vector and co--vector bundles (including higher order generalizations of the Finsler geometry and Kaluza--Klein gravity) and review the basic results on Clifford and spinor…

Differential Geometry · Mathematics 2016-09-07 Sergiu I. Vacaru , Nadejda A. Vicol

In the first part of this thesis, Kerr-Schild metrics and extended Kerr-Schild metrics are analyzed in the context of higher dimensional general relativity. Employing the higher dimensional generalizations of the Newman-Penrose formalism…

General Relativity and Quantum Cosmology · Physics 2012-04-03 Tomáš Málek

We consider black-string-type solutions in five-dimensional Einstein-Gauss-Bonnet gravity. Numerically constructed solutions under static, axially symmetric and translationally invariant metric ansatz are presented. The solutions are…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Tsutomu Kobayashi , Takahiro Tanaka

We search for the gravity description of unidentified field theories at their conformal fixed points by studying the low energy effective action of six dimensional noncritical string theory. We find constant dilaton solutions by solving…

High Energy Physics - Theory · Physics 2009-11-10 Mohsen Alishahiha , Ahmad Ghodsi , Amir E. Mosaffa

The classical Einstein--Maxwell field equations admit static horizonless wormhole solutions with only a circular cosmic string singularity. We show how to extend these static solutions to exact rotating asymptotically flat solutions. For a…

General Relativity and Quantum Cosmology · Physics 2009-07-09 Gérard Clément

We review some results concerning the properties of static, spherically symmetric solutions of multidimensional theories of gravity: various scalar-tensor theories and a generalized string-motivated model with multiple scalar fields and…

General Relativity and Quantum Cosmology · Physics 2015-06-25 K. A. Bronnikov , V. N. Melnikov