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Related papers: Constraining $f(T,\mathcal{T})$ Gravity with Gravi…

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We investigate the cosmological evolution in a new modified teleparallel theory, called $f(T,B)$ gravity, which is formulated by connecting both $f(T)$ and $f(R)$ theories with a boundary term $B$. Here, $T$ is the torsion scalar in…

General Physics · Physics 2018-11-14 M. Zubair , Saira Waheed , M. Atif Fayyaz , Iftikhar Ahmad

We present an analysis of an $f(T, \mathcal{T})$ extension of the Teleparallel Equivalent of General Relativity, where $T$ denotes the torsion and $\mathcal{T}$ the trace of the energy-momentum tensor. This extension includes non--minimal…

General Relativity and Quantum Cosmology · Physics 2016-07-27 Diego Saez-Gomez , C. Sofia Carvalho , Francisco S. N. Lobo , Ismael Tereno

We study the gravitational baryogenesis mechanism for generating baryon asymmetry in the context of running vacuum models. Regardless if these models can produce a viable cosmological evolution, we demonstrate that they produce a non-zero…

General Relativity and Quantum Cosmology · Physics 2017-09-06 V. K. Oikonomou , Supriya Pan , Rafael C. Nunes

Recently, a generalized gravity theory was proposed by Harko etal where the Lagrangian density is an arbitrary function of the Ricci scalar R and the trace of the stress-energy tensor T, known as F(R,T) gravity. In their derivation of the…

General Physics · Physics 2015-06-12 Subenoy Chakraborty

In considering alternative higher-order gravity theories, one is liable to be motivated in pursuing models consistent and inspired by several candidates of a fundamental theory of quantum gravity. Indeed, motivations from string/M-theory…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Nadiezhda Montelongo García , Tiberiu Harko , Francisco S. N. Lobo , José P. Mimoso

We present the coupling of the torsion scalar $T$ and the trace of energy-momentum tensor $\mathcal{T}$, which produces new modified $f(T,\mathcal{T})$ gravity. Moreover, we consider the functional form $f(T,\mathcal{T}) =\alpha…

General Relativity and Quantum Cosmology · Physics 2023-03-13 Simran Arora , Aaqid Bhat , P. K. Sahoo

In this paper, we have explored the observed matter-antimatter asymmetry in the Universe to constrain the model parameters in extended symmetric teleparallel gravity (STG) or $f(Q,T)$ gravity, where $Q$ be the nonmetricity and $T$ be the…

General Relativity and Quantum Cosmology · Physics 2024-05-30 S. A. Narawade , S. K. Tripathy , Raghunath Patra , B. Mishra

The growth rate of the large-scale structure of the universe has been advocated as the observable par excellence for testing gravity on cosmological scales. By considering linear-order deviations from General Relativity, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-12 Tessa Baker , Pedro G. Ferreira , Constantinos Skordis

The equation of motion for test particles in $f(R)$ modified theories of gravity is derived. By considering an explicit coupling between an arbitrary function of the scalar curvature, $R$, and the Lagrangian density of matter, it is shown…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Orfeu Bertolami , Christian G. Boehmer , Tiberiu Harko , Francisco S. N. Lobo

The modified gravity with $f(R)=R^{1+\epsilon}$ ($\epsilon>0$) allows a scaling solution where the density of gravity sector follows the density of the dominant fluid. We present initial conditions of background and perturbation variables…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Chan-Gyung Park , Jai-chan Hwang , Hyerim Noh

We consider the cosmology where some function f(G) of the Gauss-Bonnet term G is added to the gravitational action to account for the late-time accelerating expansion of the universe. The covariant and gauge invariant perturbation equations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Baojiu Li , John D. Barrow , David F. Mota

I examine how two specific examples of modified gravity explanations of cosmic acceleration help us understand some general problems confronting cosmological tests of gravity: how do we distinguish modified gravity from dark energy if they…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 Wayne Hu

The Standard Model Extension with the inclusion of gravity is studied in the framework of the gravitational baryogenesis, a mechanism to generate the baryon asymmetry based on the coupling between the Ricci scalar curvature and the baryon…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Lambiase

In standard approach to cosmological modeling in the framework of general relativity, the energy conditions play an important role in the understanding of several properties of the Universe, including singularity theorems, the current…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-10 Di Liu , M. J. Reboucas

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

LHC provides a excellent laboratory to probe massive gravitons effects in scenarios with low scale gravity up to several Tev. Based on this fact, in the present work we are interested in analyzing the possible constraints on the free…

General Relativity and Quantum Cosmology · Physics 2016-11-26 J. A. Helayël Neto , N. Panza

Nonlinear generalizations of teleparallel gravity entail the modification of a Lagrangian that is pseudoinvariant under local Lorentz transformations of the tetrad field. This procedure consequently leads to the loss of the local…

General Relativity and Quantum Cosmology · Physics 2020-04-27 Rafael Ferraro , María José Guzmán

We discuss the validity of the energy conditions in a newly modified theory named as $f(R,T,R_{\mu\nu}T^{\mu\nu})$ gravity, where $R$ and $T$ represent the scalar curvature and trace of the energy-momentum tensor. The corresponding energy…

General Relativity and Quantum Cosmology · Physics 2014-02-20 M. Sharif , M. Zubair

The amplification of the primordial magnetic fields and the gravitational baryogenesis, a mechanism that allows to generate the baryon asymmetry in the Universe by means of the coupling between the Ricci scalar curvature and the baryon…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-18 Herman J. Mosquera Cuesta , Gaetano Lambiase

The gravitational baryogensis may not generate a sufficient baryon asymmetry in the standard thermal history of the Universe when we take into account the gravitino problem. Hence it has been suggested that anisotropy of the Universe can…

High Energy Physics - Phenomenology · Physics 2016-06-01 Mitsuhiro Fukushima , Shuntaro Mizuno , Kei-ichi Maeda