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In this paper we use the conformal teleparallel gravity to study an isotropic and homogeneous Universe which is settled by the FRW metric. We solve the field equations and we obtain the behavior of some cosmological parameters such as scale…

General Relativity and Quantum Cosmology · Physics 2016-03-30 J. G. Silva , A. F. Santos , S. C. Ulhoa

In this article, we investigate the observed cosmic acceleration in the framework of a cosmological $f(R,L_m)$ model dominated by bulk viscous matter in an anisotropic background. We consider the LRS Bianchi type I metric and derive the…

General Relativity and Quantum Cosmology · Physics 2023-06-14 Raja Solanki , Bina Patel , Lakhan V. Jaybhaye , P. K. Sahoo

In this paper, we consider spatially flat FLRW cosmological models in two contexts in an attempt to derive a set of conditions that characterize when such models exhibit oscillatory behaviour. In the first case, we consider a spatially flat…

General Relativity and Quantum Cosmology · Physics 2017-06-12 Ikjyot Singh Kohli

$f(Q,T)$ 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…

General Relativity and Quantum Cosmology · Physics 2023-05-24 Tee-How Loo , M. Koussour , Avik De

Brane-world cosmology is motivated by recent developments in string/M-theory and offers a new perspective on the hierarchy problem. In the brane-world scenario, our Universe is a four-dimensional subspace or {\em brane} embedded in a…

Astrophysics · Physics 2009-11-11 A. A. Coley

We discuss the dynamical analysis in $f(R,T)$ gravity (where $R$ is Ricci scalar and $T$ is trace of energy momentum tensor) for gravitating sources carrying axial symmetry. The self gravitating system is taken to be anisotropic and line…

General Relativity and Quantum Cosmology · Physics 2015-06-25 M. Zubair , Ifra Noureen

We investigate a non-minimally coupled scalar field theory within the framework of scalar-tensor gravity formulated in non-metricity geometry, focusing on spatially curved FLRW spacetimes. Employing the dynamical systems approach with…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Ghulam Murtaza , Avik De , Andronikos Paliathanasis

Systems of self-gravitating fermions constitute a topic of great interest in astrophysics, due to the wide field of applications. In this paper, we consider the gravitational equilibrium of spherically symmetric Newtonian models of…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-01 Marco Merafina , Giuseppe Alberti

Utilizing the autonomous system of ordinary differential equations derived in arXiv:1809.01458 to define the evolution, we further investigate a class of cosmological models within an Einstein-aether gravitational framework by introducing a…

General Relativity and Quantum Cosmology · Physics 2024-02-28 S. Mohandas , R. J. van den Hoogen , D. Winters , M. Dala

In this paper, we analyze stability regions of a non-static restricted class of axially symmetric spacetime with anisotropic matter distribution. We consider $f(R)=R+{\epsilon}R^2$ model and assume hydrostatic equilibrium of the axial…

General Relativity and Quantum Cosmology · Physics 2014-11-19 M. Sharif , Z. Yousaf

We determine the leading order fall-off behaviour of the Weyl tensor in higher dimensional Einstein spacetimes (with and without a cosmological constant) as one approaches infinity along a congruence of null geodesics. The null congruence…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Marcello Ortaggio , Alena Pravdová

$f(R)$ gravity models belong to an important class of modified gravity models where the late time cosmic accelerated expansion is considered as the manifestation of the large scale modification of the force of gravity. $f(R)$ gravity models…

General Relativity and Quantum Cosmology · Physics 2013-08-27 Umananda Dev Goswami , Kabita Deka

The conformal anomaly in curved spacetime generates a nontrivial anomalous vertex, given by the three-point correlation function $TTT$ of the energy-momentum tensor $T^{\mu\nu}$. We show that a temperature inhomogeneity in a gas of charged…

High Energy Physics - Theory · Physics 2020-01-22 M. N. Chernodub , Claudio Corianò , Matteo Maria Maglio

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…

General Relativity and Quantum Cosmology · Physics 2019-08-01 Özcan Sert , Muzaffer Adak

In this work we investigate several theoretical and phenomenological implications of a scalar -$F(R)$ gravity containing a non-minimal coupling to the scalar curvature. This kind of model is a generalization of axion-$F(R)$ gravity models,…

General Relativity and Quantum Cosmology · Physics 2020-05-20 Shin'ichi Nojiri , S. D. Odintsov , V. K. Oikonomou

We propose a new model of modified $F(R)$ gravity theory with the function $F(R) = (1/\beta) \arcsin(\beta R)$. Constant curvature solutions corresponding to the flat and de Sitter spacetime are obtained. The Jordan and Einstein frames are…

General Physics · Physics 2015-07-24 S. I. Kruglov

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 the work, we present investigation on decoupling gravitational sources under the framework of $f(R,T)$ gravity. Basically the complete geometric deformation technique has been employed here which facilitates finding exact solutions to…

General Relativity and Quantum Cosmology · Physics 2024-03-21 S. K. Maurya , B. Mishra , Saibal Ray , Riju Nag

We construct a model of a universe filled with a perfect fluid with isotropic particle pressure. The anisotropic plane symmetric Kasner spacetime is used as a seed metric and through a conformal mapping a perfect fluid is generated. The…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Sudan Hansraj , Megandhren Govender , Narenee Mewalal

In this work, we study the possibility of finite-time future cosmological singularities appearing in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. We present the theory in both the…

General Relativity and Quantum Cosmology · Physics 2022-05-10 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo