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Related papers: Cylindrical solutions in Mimetic gravity

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This topical review deals with a multidimensional gravitational model containing dilatonic scalar fields and antisymmetric forms. The manifold is chosen in the form M = M_0 x M_1 x ...x M_n, where M_i are Einstein spaces (i >0). The…

High Energy Physics - Theory · Physics 2010-04-06 V. D. Ivashchuk , V. N. Melnikov

Inspired by some recent works of Lovelock Brans-Dicke gravity and mimetic gravity, cosmology solutions in extensions of these two modified gravities are investigated. A non-local term is added to the Lovelock Brans-Dicke action and…

General Relativity and Quantum Cosmology · Physics 2016-12-14 Yi Zhong , Emilio Elizalde

In this work, exact solutions of static and spherically symmetric space-times are analyzed in f(R) modified theories of gravity coupled to nonlinear electrodynamics. Firstly, we restrict the metric fields to one degree of freedom,…

General Relativity and Quantum Cosmology · Physics 2012-06-22 Lukas Hollenstein , Francisco S. N. Lobo

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

We consider Kasner-type static, cylindrically symmetric interior string solutions in the $f\left(R,L_m\right)$ theory of modified gravity. The physical properties of the string are described by an anisotropic energy-momentum tensor…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Tiberiu Harko , Matthew J. Lake

We complete the proof of Weinberg's no-go theorem on the cosmological constant problem in classical gravity when the theory has a (global) scale symmetry. Stimulated with this proof, we explore a solution to the cosmological constant…

High Energy Physics - Theory · Physics 2018-12-27 Ichiro Oda

We consider equations of modified gravity involving critical accelerations and find its solutions for the point-like source by suggesting the appropriate symmetry of metrics in the empty space-time.

General Physics · Physics 2019-11-28 Ja. V. Balitsky , V. V. Kiselev

In this paper, we study the various cylindrical solutions (cosmic strings) in gravity's rainbow scenario. In particular, we calculate the gravitational field equations corresponding to energy-dependent background. Further, we discuss the…

General Relativity and Quantum Cosmology · Physics 2017-08-03 Davood Momeni , Sudhaker Upadhyay , Yerlan Myrzakulov , Ratbay Myrzakulov

We study spherically symmetric solutions in a covariant massive gravity model, which is a candidate for a ghost-free non-linear completion of the Fierz-Pauli theory. There is a branch of solutions that exhibits the Vainshtein mechanism,…

High Energy Physics - Theory · Physics 2011-11-04 Kazuya Koyama , Gustavo Niz , Gianmassimo Tasinato

Certain versions of mimetic gravity have recently been claimed to present potential covariant theories of canonically modified spherically symmetric gravity, motivated by ingredients from loop quantum gravity. If such an equivalence were to…

General Relativity and Quantum Cosmology · Physics 2024-04-22 Martin Bojowald , Erick I. Duque

We consider dynamics of a flat anisotropic Universe filled by a perfect fluid near a cosmological singularity in quadratic gravity. Two possible regimes are described -- the Kasner anisotropic solution and an isotropic "vacuum radiation"…

General Relativity and Quantum Cosmology · Physics 2017-01-04 A. Toporensky , D. Müller

Massive gravity may be viewed as a suitable limit of bimetric gravity. The limiting procedure can lead to an interesting interplay between the "background" and "foreground" metrics in a cosmological context. The fact that in bimetric…

General Relativity and Quantum Cosmology · Physics 2013-02-13 Prado Martin-Moruno , Valentina Baccetti , Matt Visser

We present an exact stationary {\it axially symmetric} vacuum solution of metric-affine gravity (MAG) which generalises the recently reported spherically symmetric solution. Besides the metric, it carries nonmetricity and torsion as…

General Relativity and Quantum Cosmology · Physics 2009-10-28 E. J. Vlachynsky , R. Tresguerres , Yu. N. Obukhov , F. W. Hehl

We find new solutions to the Einstein-Maxwell equations in the presence of mimetic field in $ D $ dimensions, all of which are asymptotically Antide Sitter. We derive the solutions in five-dimensional spacetime, in detail. By extending the…

General Relativity and Quantum Cosmology · Physics 2022-07-13 Hamid R. Bakhtiarizadeh

We study some properties of exact cosmological solutions for a flat multidimensional anisotropic Universe in Lovelock gravity. A particular attention is paid to some features of solution in a general Lovelock gravity which have no their…

General Relativity and Quantum Cosmology · Physics 2014-06-11 S. Pavluchenko , A. Toporensky

One of the most important achievements in general relativity has been discovery of the $(2+1)$-dimensional black hole solutions of Einstein gravity in anti-de Sitter (AdS) spacetime [Phys. Rev. Lett. {\bf69}, 1849 (1992)]. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2021-02-12 Ahmad Sheykhi

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

A method is presented to construct a particular, non-minimally coupled scalar-tensor theory such that a given metric is an exact vacuum solution in that theory. In contrast to the standard approach in studies of gravitational dynamics,…

General Relativity and Quantum Cosmology · Physics 2021-01-13 Arthur G. Suvorov

The idea of "asymptotically free" gravity is implemented using a constrained mimetic scalar field. The effective gravitational constant is assumed to vanish at some limiting curvature. As a result singularities in contracting spatially flat…

High Energy Physics - Theory · Physics 2020-08-05 Ali H. Chamseddine , Viatcheslav Mukhanov , Tobias Russ

In this work, we derive the general solutions for a cylindrically symmetric space-time filled with a cosmological perfect fluid obeying $p=\gamma \rho$ ($0\leq \gamma \leq 1$), where $\gamma=1$ represents a stiff or Zeldovich fluid. Using…

General Relativity and Quantum Cosmology · Physics 2026-04-06 Tiberiu Harko , Francisco S. N. Lobo , Man Kwong Mak