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Related papers: Power-law solutions in $f(T)$ gravity

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Considering some modified Newtonian potentials and the Hubble law in writing the total energy of a test mass located at the edge of a flat Friedmann-Robertson-Walker universe, we obtain several modified Friedmann equations. Interestingly…

General Physics · Physics 2019-04-16 M. Kord Zangeneh , H. Moradpour , N. Sadeghnezhad

This paper explores stability of the Einstein universe against linear homogeneous perturbations in the background of $f(\mathcal{G},T)$ gravity. We construct static as well as perturbed field equations and investigate stability regions for…

General Relativity and Quantum Cosmology · Physics 2017-07-26 M. Sharif , Ayesha Ikram

We present the first formulation of the recently proposed $f(R,\mathcal{L}_m,T)$ theory of gravity within the Palatini formalism, a well-known alternative variational approach where the metric and connection are treated as independent…

General Relativity and Quantum Cosmology · Physics 2024-11-26 J. G. de Lima Júnior , P. H. R. S. Moraes , E. Brito , J. A. S. Fortunato

We seek to obtain a new class of exact solutions of regular black holes in $f(T)$ Gravity with non-linear electrodynamics material content, with spherical symmetry in $4D$. The equations of motion provide the regaining of various solutions…

General Relativity and Quantum Cosmology · Physics 2015-11-02 Ednaldo L. B. Junior , Manuel E. Rodrigues , Mahouton J. S. Houndjo

A flat Fiedmann-Robertson-Walker (FRW) multi-scalar field cosmology is studied with a particular potential of the form $ \rm V(\phi,\sigma)=V_0 e^{-\lambda_1 \phi-\lambda_2 \sigma}$, which emerges as a relation between the time derivatives…

General Relativity and Quantum Cosmology · Physics 2019-11-21 J. Socorro , Omar E. Núñez , Rafael Hernández-Jiménez

It has been known for some time that the cosmological Friedmann equation deduced from General Relativity can be also obtained within the Newtonian framework under certain assumptions. We use this result together with quantum corrections to…

General Relativity and Quantum Cosmology · Physics 2016-11-03 Pedro Bargueño , Sergio Bravo-Medina , Marek Nowakowski , Davide Batic

The main objective of this thesis is to discuss scalar-tensor theories in the Palatini approach. Both scalar-tensor theories and Palatini formalism are means of alternating classical theory of gravity, general relativity, in order to…

General Relativity and Quantum Cosmology · Physics 2017-10-27 Aleksander Kozak

The asymptotic solutions of cosmological topologically massive gravity (TMG) are analyzed for values of the mass parameter in the range $\mu\geq1$. At non-chiral values, a new term in the Fefferman-Graham expansion is needed to capture the…

High Energy Physics - Theory · Physics 2011-09-22 Colin Cunliff

A new approach to tackle Einstein equations for an isotropic and homogeneous Friedmann--Robertson--Walker Universe in the presence of a quintessence scalar field is devised. It provides a way to get a simple exact solution to these…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Felipe A. Asenjo , Sergio A. Hojman

The recently proposed $f(Q, T)$ gravity (Xu et al. Eur. Phys. J. C \textbf{79} (2019) 708) is an extension of the symmetric teleparallel gravity. The gravitational action $L$ is given by an arbitrary function $f$ of the non-metricity $Q$…

General Relativity and Quantum Cosmology · Physics 2020-10-02 Simran Arora , P. K. Sahoo

The $f(T)$ theory is recently proposed to explain the present cosmic accelerating expansion of the universe. $f(T)$ theory is an extension of Teleparallel theory of gravity, where $T$ is the torsion scalar. This paper contains the…

General Relativity and Quantum Cosmology · Physics 2015-02-04 M. Jamil Amir , M. Yussouf

We propose an $f(T)$ teleparallel gravity theory including a torsional infrared (IR) correction. We show that the governing Friedmann's equations of a spatially flat universe include a phantom-like effective dark energy term sourced by the…

General Relativity and Quantum Cosmology · Physics 2019-02-04 Amr El-Zant , Waleed El Hanafy , Sherif Elgammal

We study spherically symmetric solutions in f(R) theories and its compatibility with local tests of gravity. We start by clarifying the range of validity of the weak field expansion and show that for many models proposed to address the Dark…

General Relativity and Quantum Cosmology · Physics 2010-10-27 I. Navarro , K. Van Acoleyen

In this paper, we investigate time-dependent Kantowski--Sachs spherically symmetric teleparallel $F(T)$ gravity with a scalar field source. We begin by setting the exact field equations to be solved and solve conservation laws for possible…

General Relativity and Quantum Cosmology · Physics 2025-01-22 Alexandre Landry

We consider a generalized teleparallel theory of gravitation, where the action contains an arbitrary function of the torsion scalar and a scalar field, $f(T,\phi)$, thus encompassing the cases of $f(T)$ gravity and nonminimally coupled…

General Relativity and Quantum Cosmology · Physics 2018-05-23 Manuel Hohmann , Laur Järv , Ulbossyn Ualikhanova

We construct $F(T,\left(\nabla{T}\right)^2,\Box {T})$ gravitational modifications, which are novel classes of modified theories arising from higher-derivative torsional terms in the action, and are different than their curvature analogue.…

General Relativity and Quantum Cosmology · Physics 2016-10-19 Giovanni Otalora , Emmanuel N. Saridakis

The Friedmann equations of Cotton gravity provide a simple parametrization to reproduce, by tuning a single function, the Friedmann equations of several extensions of gravity, such as f(R), modified Gauss-Bonnet f(G), teleparallel f(T), and…

General Relativity and Quantum Cosmology · Physics 2024-02-26 Carlo Alberto Mantica , Luca Guido Molinari

A solution to Einstein's field equations via the Friedman equations is shown to produce a cosmological model that is in exact agreement with the measurements made by the dark energy astronomers. All the essential physical parameters are…

General Physics · Physics 2012-06-26 James G. Gilson

A Friedmann like cosmological model in Einstein-Cartan framework is studied when the torsion function is assumed to be proportional to a single $\phi(t)$ function coming just from the spin vector contribution of ordinary matter. By…

General Relativity and Quantum Cosmology · Physics 2019-11-21 S. H. Pereira , R. de C. Lima , J. F. Jesus , R. F. L. Holanda

This paper is devoted to study the energy conditions in F(R,T) gravity for FRW universe with perfect fluid, where $R$ is the Ricci scalar and $T$ is the torsion scalar. We construct the general energy conditions in this theory and reduce…

General Relativity and Quantum Cosmology · Physics 2013-10-23 M. Sharif , S. Rani , R. Myrzakulov