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Related papers: Geodesic Deviation Equation in $f (R,T)$ Gravity

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We shall investigate the properties of a congruence of geodesics in the framework of Palatini f(R) theories. We shall evaluate the modified geodesic deviation equation and the Raychaudhuri's equation and show that f(R) Palatini theories do…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Fatimah Shojai , Ali Shojai

In this paper, we discuss cosmological application of holographic Dark Energy (HDE) in the framework of $f(G)$ modified gravity. For this purpose, we construct $f(G)$ model with the inclusion of HDE and a well-known power law form of the…

General Physics · Physics 2015-06-12 Abdul Jawad , Antonio Pasqua , Surajit Chattopadhyay

Teleparallel theories of gravity are described in terms of the tetrad of a metric and a flat connection with torsion. In this paper, we study spherical symmetry in a modified teleparallel theory of gravity which is based on an arbitrary…

General Relativity and Quantum Cosmology · Physics 2021-05-06 Sebastian Bahamonde , Christian Pfeifer

We discuss the f(R)-theories of gravity with torsion in the framework of jet-bundles. Such an approach is particularly useful since the components of the torsion and curvature tensors can be chosen as fiber jet-coordinates on the bundles…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Capozziello , R. Cianci , C. Stornaiolo , S. Vignolo

In this paper, I consider a $f(R, G, T)$ modified gravity model where $R$ represents the Ricci scalar, $G$ denotes the Gauss-Bonnet invariant, and $T$ signifies the trace of the stress-energy tensor. This model is coupled with two distinct…

General Relativity and Quantum Cosmology · Physics 2024-09-04 Farzad Milani

We consider modified teleparallel gravity, (f(T) gravity), as a framework to explain the present accelerated expansion of the universe. The matter component is assumed to be cold dark matter. To find the explicit form of the function $f$,…

General Relativity and Quantum Cosmology · Physics 2015-06-11 H. Mohseni Sadjadi

We study the geodesic deviation (GD) equation in a generalized version of the S\'{a}ez--Ballester (SB) theory in arbitrary dimensions. We first establish a general formalism and then restrict to particular cases, where (i) the matter-energy…

General Relativity and Quantum Cosmology · Physics 2022-09-27 S. M. M. Rasouli , M. Sakellariadou , Paulo Vargas Moniz

We analyse the implications of the presence of spatial curvature in modified gravity models. As it is well known, the current standard cosmological model, the $\Lambda$CDM, is assumed to be spatially flat based on the results of many…

General Relativity and Quantum Cosmology · Physics 2024-12-03 Serena Gambino , Francesco Pace

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

We show that the gravitational field equations derived from an action composed of i) an arbitrary function of the scalar curvature and other scalar fields plus ii) connection-independent kinetic and source terms, are identical whether one…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Jean-paul Berthias , Bahman Shahid-Saless

For cosmologically interesting $f(R)$ gravity models, we derive the complete set of the linearized field equations in the Newtonian gauge, under environments of the solar system, galaxies and clusters respectively. Based on these equations,…

Astrophysics · Physics 2008-11-26 Pengjie Zhang

The $f(R,T)$ theory of gravitation is an extended theory of gravitation in which the gravitational action contains both the Ricci scalar $R$ and the trace of energy momentum tensor $T$ and hence the cosmological models based on $f(R,T)$…

General Physics · Physics 2020-04-14 Nishant Singla , Mukesh Kumar Gupta , Anil Kumar Yadav

Motivated by earlier works on reconstruction of modified gravity models with dark energy components, we extend them by considering a newly proposed model of (m, n)- type of holographic dark energy for two models of modified gravity, f(R)…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-14 M. Umar Farooq , Mubasher Jamil , Davood Momeni , Ratbay Myrzakulov

The $f(R,T)$ gravity is a model whose action contains an arbitrary function of the Ricci scalar $R$ and the trace of the energy-momentum tensor $T$. We consider the separable model $f (R, T ) = \chi(R) + \varphi(T )$ and shown that, for…

General Relativity and Quantum Cosmology · Physics 2023-06-29 Nicolas R. Bertini , Hermano Velten

Einstein's equations of gravitation are not invariant under geodesic mappings, i. e. under a certain class of mappings of the Christoffel symbols and the metric tensor which leave the geodesic equations in a given coordinate system…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Leonid V. Verozub

In this work, we present a review of Energy-Momentum Squared Gravity (EMSG) -- more specifically, $f(R,T_{\mu\nu}T^{\mu\nu})$ gravity, where $R$ represents the Ricci scalar and $T_{\mu\nu}$ denotes the energy-momentum tensor. The inclusion…

General Relativity and Quantum Cosmology · Physics 2024-08-27 Ricardo A. C. Cipriano , Nailya Ganiyeva , Tiberiu Harko , Francisco S. N. Lobo , Miguel A. S. Pinto , João Luís Rosa

We investigate cosmological solutions of f(R,T) modified theories of gravity for perfect fluid in spatially FLRW metric through phase space analysis, where R is Ricci scalar and T denotes the trace of energy-momentum tensor of matter…

General Relativity and Quantum Cosmology · Physics 2017-05-23 Hamid Shabani , Mehrdad Farhoudi

In this work, we study the late-time cosmological solutions of f(R,T)=g(R)+h(-T) models assuming that the conservation of the energy-momentum tensor (EMT) is violated. We perform our analysis through constructing an autonomous dynamical…

General Relativity and Quantum Cosmology · Physics 2017-08-07 Hamid Shabani , Amir Hadi ziaie

This paper is devoted to investigate the recently introduced $f(\mathcal{G},\textit{T})$ theory of gravity, where $\mathcal{G}$ is the Gauss-Bonnet term, and ${\textit{T}}$ is the trace of the energy-momentum tensor. For this purpose,…

General Physics · Physics 2017-12-13 M. Farasat Shamir

This paper studies the reconstruction criterion in the framework of $f(Q,T)$ gravity using ghost dark energy model, where $Q$ represents the non-metricity and $T$ is the trace of energy-momentum tensor. In this regard, the correspondence…

General Relativity and Quantum Cosmology · Physics 2024-05-09 M. Sharif , Iqra Ibrar
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