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相关论文: On Kasner solution in Bianchi I $f(T)$ cosmology

200 篇论文

We investigate the evolution of cosmological anisotropies within the framework of $f\left(G\right)$-gravity. Specifically, we consider a locally rotationally symmetric geometry in four-dimensional spacetime that describes the Bianchi I,…

广义相对论与量子宇宙学 · 物理学 2025-12-25 R. Bogadi , A. Giacomini , M. Govender , C. Hansraj , G. Leon , A. Paliathanasis

We use one of the simplest forms of the K-essence theory and we apply it to the classical anisotropic Bianchi type I cosmological model, with a barotropic perfect fluid modeling the usual matter content and with cosmological constant. The…

广义相对论与量子宇宙学 · 物理学 2014-09-11 J. Socorro , Luis O. Pimentel , Abraham Espinoza-García

In the present paper an attempt has been made to study the spatially homogeneous and isotropic FRW model and axially symmetric spacetime in f(R) theory of gravity. We have obtained the solutions of the field equations in vacuum. To find the…

广义相对论与量子宇宙学 · 物理学 2017-03-21 P. K. Agrawal , D. D. Pawar

The dynamics of a self-gravitating neutron gas in presence of a magnetic field is being studied taking the equation of state of a magnetized neutron gas obtained in a previous study [2]. We work in a Bianchi I spacetime characterized by a…

天体物理学 · 物理学 2008-10-15 D. Manreza Paret

It is well-known that static vacuum solutions of Einstein equations are analytic in suitable coordinates. We ask here for an extension of this result in the context of Finsler gravity. We consider Finsler spacetimes that retain several…

微分几何 · 数学 2020-04-23 Erasmo Caponio , Antonio Masiello

We study the dynamics of homogeneous isotropic FRW cosmologies with positive spatial curvature in $f(R)$-gravity, paying special attention to the existence of Einstein static models and only study forms of $f(R)=R^n$ for which these static…

广义相对论与量子宇宙学 · 物理学 2009-04-17 Naureen Goheer , Rituparno Goswami , Peter K. S. Dunsby

We propose that the solution to the cosmological vacuum energy puzzle may come from the infrared sector of the effective theory of gravity, where the impact of the trace anomaly is of upmost relevance. We proceed by introducing two…

广义相对论与量子宇宙学 · 物理学 2009-08-12 Evan C. Thomas , Federico R. Urban , Ariel R. Zhitnitsky

We consider a D dimensional Kasner type diagonal spacetime where metric functions depend only on a single coordinate and electromagnetic field shares the symmetries of spacetime. These solutions can describe static cylindrical or…

广义相对论与量子宇宙学 · 物理学 2013-10-31 Özgür Delice , Pınar Kirezli , Dilek K. Çiftci

A bouncing universe is a viable candidate to solve the initial singularity problem. Here we consider bouncing solutions in the context of $f(R,\mathcal{G})$ gravity by using an order reduction technique which allows one to find solutions…

广义相对论与量子宇宙学 · 物理学 2020-06-24 Bruno J. Barros , Elsa M. Teixeira , Daniele Vernieri

In this paper we analyze spherically symmetric static vacuum solutions with various topologies in mimetic gravity. When the Einstein's tensor is different from zero, a new class of solutions different from the Schwarzschild one emerges from…

广义相对论与量子宇宙学 · 物理学 2015-09-21 Ratbay Myrzakulov , Lorenzo Sebastiani

This manuscript is devoted to investigate Bianchi Type $I$ universe in the context of $f(R,T)$ gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type $I$ spacetime. The modified field…

综合物理 · 物理学 2015-08-07 M. Farasat Shamir

The dynamics and evolution of Bianchi type I space-times is considered in the framework of the four-dimensional truncation of a reduced theory obtained from the N=2,D=5 supergravity. The general solution of the gravitational field equations…

高能物理 - 理论 · 物理学 2009-10-31 Chiang-Mei Chen , T. Harko , M. K. Mak

In this paper, we investigate the behavior of equation of state parameter and energy density for dark energy in the framework of f(T) gravity. For this purpose, we use anisotropic LRS Bianchi type I universe model. The behavior of…

广义相对论与量子宇宙学 · 物理学 2015-06-15 M. Sharif , Sehrish Azeem

$f(Q,T)$ theory of gravity is very recently proposed to incorporate within the action Lagrangian, the trace $T$ of the energy-momentum tensor along with the non-metricity scalar $Q$. The cosmological application of this theory in a…

广义相对论与量子宇宙学 · 物理学 2023-05-24 Tee-How Loo , M. Koussour , Avik De

We show under the assumption of small data that solutions to the Einstein-Vlasov system with a pure magnetic field and Bianchi I symmetry isotropise and tend to dust solutions. We also obtain the decay rates for the main variables. This…

广义相对论与量子宇宙学 · 物理学 2024-06-18 Ho Lee , Ernesto Nungesser

Considering the condition on conservation of energy momentum tensor (EMT), we study late time cosmological solutions in the context of $f(R,T)=R+\alpha T^{n}$ gravity (where $\alpha$ and $n$ are constants) in a flat FLRW spacetime. The…

广义相对论与量子宇宙学 · 物理学 2024-03-06 Hamid Shabani , Norman Cruz , Amir Hadi Ziaie

We present a brief review of the modified Brans-Dicke theory (MBDT) in arbitrary dimensions, whereby the ($N+1$)-dimensional field equations reduce to the $N$-dimensional $(ND)$ configuration with sources and an effective induced scalar…

广义相对论与量子宇宙学 · 物理学 2014-05-27 S. M. M. Rasouli

Applying a non-diagonal spherically symmetric tetrad field having arbitrary function, $S(r)$, that is corresponding to local Lorentz transformation, to the field equations of f(T) gravity theories. An analytic vacuum solutions with…

综合物理 · 物理学 2015-06-11 Gamal G. L. Nashed

We investigate the existence of anisotropic self-similar exact solutions in symmetric teleparallel $f\left( Q\right)$-theory. For the background geometry we consider the Kantowski-Sachs and the Locally Rotationally Symmetric Bianchi type…

广义相对论与量子宇宙学 · 物理学 2023-08-29 N. Dimakis , M. Roumeliotis , A. Paliathanasis , T. Christodoulakis

We investigate anisotropic cosmological solutions of the theory with non-minimal couplings between electromagnetic fields and gravity in $Y(R) F^2$ form. After we derive the field equations by the variational principle, we look for…

广义相对论与量子宇宙学 · 物理学 2019-08-01 Özcan Sert , Muzaffer Adak