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Related papers: G\"{o}del-type solution in $f(R,T)$ modified gravi…

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In literature there is a model of modified gravity in which the matter Lagrangian is coupled to the geometry via trace of the stress-energy momentum tensor $T=T_{\mu}^{\mu}$. This type of modified gravity is called as $f(R,T)$ in which $R$…

General Relativity and Quantum Cosmology · Physics 2016-08-30 M. J. S. Houndjo , M. E. Rodrigues , N. S. Mazhari , D. Momeni , R. Myrzakulov

In the Rastall gravity a non-minimal coupling between geometry and matter fields is considered. Then the usual energy-momentum tensor conservation law is not valid. Here a Lagrangian formalism is proposed to the Rastall theory of gravity.…

General Relativity and Quantum Cosmology · Physics 2019-12-16 W. A. G. De Moraes , A. F. Santos

We examine the question as to whether the Palatini f(R) gravity theories permit space-times in which the causality is violated. We show that every perfect-fluid G\"{o}del-type solution of Palatini f(R) gravity with density $\rho$ and…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-30 J. Santos , M. J. Reboucas , T. B. R. F. Oliveira

We investigate equations of motion and future singularities of $f(R,T)$ gravity where $R$ is the Ricci scalar and $T$ is the trace of stress-energy tensor. Future singularities for two kinds of equation of state (barotropic perfect fluid…

General Relativity and Quantum Cosmology · Physics 2018-08-21 Behrouz Mirza , Fatemeh Oboudiat

In this paper, we deal with the $f(R,Q)$ gravity whose action depends, besides of the scalar curvature $R$, on the higher-derivative invariant $Q=R_{\mu\nu}R^{\mu\nu}$. In order to compare this theory with the usual General Relativity (GR),…

High Energy Physics - Theory · Physics 2017-09-14 F. S. Gama , J. R. Nascimento , A. Yu. Petrov , P. J. Porfirio , A. F. Santos

In this paper, we study the behavior of perfect fluid and massless scalar field for homogeneous and anisotropic Bianchi type I universe model in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Muhammad Sharif , Muhammad Zubair

Here in this work we propose a modified gravity with the action of $f(R) = \sqrt{R^2 - R_0^2}$ instead of Einstein-Hilbert action to describe the late time acceleration of the universe. We obtain the equation of the modified gravity both in…

Astrophysics · Physics 2008-11-26 Shant Baghram , Marzieh Farhang , Sohrab Rahvar

In this paper, we investigate irregularities in a cylindrical self-gravitating system which contains the properties of an imperfect matter and electromagnetic field. For $f(R,T,Q)$ theory, in which $R$ represents the Ricci scalar and $T$…

General Physics · Physics 2021-08-30 Z. Yousaf , M. Z. Bhatti , T. Naseer , I. Ahmad

We study scalar cosmological perturbations in $f(R, T)$ modified gravity theories being $T$ the trace of the energy-momentum tensor. We provide detailed equations for the matter energy density contrast. We solve then numerically to promote…

General Relativity and Quantum Cosmology · Physics 2024-08-28 Jonas Pinheiro da Silva , Hermano Velten

The energy conditions are derived in the context of $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor, which can reduce to the well-known conditions in $f(R)$ gravity and general relativity.…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Muhammad Sharif , Muhammad Zubair

We consider the Palatini formulation of $f(R,T)$ gravity theory, in which a nonminimal coupling between the Ricci scalar and the trace of the energy-momentum tensor is introduced, by considering the metric and the affine connection as…

General Relativity and Quantum Cosmology · Physics 2018-07-24 Jimin Wu , Guangjie Li , Tiberiu Harko , Shi-Dong Liang

We consider cosmological scenarios based on $f(R,T)$ theories of gravity ($R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor) and numerically reconstruct the function $f(R,T)$ which is able to reproduce the same…

General Relativity and Quantum Cosmology · Physics 2015-03-19 M. J. S. Houndjo , Oliver F. Piattella

This article concerns with the characterization of a spacetime and modified gravity, such as $f\left(R,G\right)$, $f\left(R,T\right)$ and $f\left(R,L_{m}\right)$-gravity equipped with the projective curvature tensor. We establish that a…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Young Jin Suh , Krishnendu De , Uday Chand De

The aim of this paper is to introduce a new modified gravity theory named as $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ are the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively) and investigate energy…

General Relativity and Quantum Cosmology · Physics 2016-12-21 M. Sharif , Ayesha Ikram

The main purpose of this paper is to investigate the exact solutions of cylindrically symmetric spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an arbitrary function of Ricci scalar $R$ and trace of the energy momentum…

General Relativity and Quantum Cosmology · Physics 2015-07-01 M. Farasat Shamir , Zahid Raza

In this paper, we investigate the modified Geodesic Deviation Equation (GDE) in the framework of $f(R,T)$ theory of gravity where $R$ and $T$ are the curvature scalar and the trace of the energy-momentum tensor, respectively, using the FLRW…

General Relativity and Quantum Cosmology · Physics 2017-05-04 E. H. Baffou , M. J. S. Houndjo , M. E. Rodrigues , A. V. Kpadonou , J. Tossa

In this article, we considered the bulk viscous fluid in the formalism of modified gravity in which the general form of a gravitational action is $f(R, T)$ function, where $R$ is the curvature scalar and $T$ is the trace of the energy…

General Relativity and Quantum Cosmology · Physics 2017-08-02 G. C. Samanta , R. Myrzakulov

We apply cosmological reconstruction methods to the $f(R,T)$ modified gravity, in its recently developed scalar-tensor representation. We do this analysis assuming a perfect fluid in a Friedmann-Lema\^{i}tre-Robsertson-Walker (FLRW)…

General Relativity and Quantum Cosmology · Physics 2024-07-24 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

A plane symmetric Bianchi-I model is explored in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor. The solutions are obtained with the consideration of a specific Hubble parameter which yields a…

General Relativity and Quantum Cosmology · Physics 2020-03-23 Vijay Singh , Aroonkumar Beesham

We propose a new model of gravity where the Ricci scalar (R) in Einstein-Hilbert action is replaced by an arbitrary function of R and of the norm of energy-momentum tensor i.e., $f(R,T_{\mu\nu}T^{\mu\nu})$. Field equations are derived in…

General Relativity and Quantum Cosmology · Physics 2014-08-04 N. Katirci , Mehmet Kavuk