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In this Reply we reassert the failure of the model $f(R,T)=R+\alpha T+ \beta T^2$ in providing a transition from deceleration to an accelerated stage as we have pointed out in [H. Velten and Thiago R. P. Caram\^es, Phys. Rev. D 95 (2017)…

广义相对论与量子宇宙学 · 物理学 2017-09-26 Hermano Velten , Thiago Carames

In this work we present cosmological solutions from the simplest non-trivial $T$-dependence in $f(R,T)$ theory of gravity, with $R$ and $T$ standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Although such…

高能物理 - 理论 · 物理学 2016-06-29 P. H. R. S. Moraes , G. Ribeiro , R. A. C. Correa

Among many alternative gravitational theories to General Relativity (GR), $f(R,T)$ gravity (where $R$ is the Ricci scalar and $T$ the trace of the energy-momentum tensor) has been widely studied recently. By adding a matter contribution to…

广义相对论与量子宇宙学 · 物理学 2017-07-05 Hermano Velten , Thiago R. P. Caramês

This work examines the cosmological implications of two functional forms of $f(R,T) = R + \alpha T^n$ gravity: for two different value of $n $ where $n=1$ and $n\neq 1$, and $\alpha$ and $n$ are free parameters. The modified Friedmann…

宇宙学与河外天体物理 · 物理学 2026-02-24 Mustapha Lamaaoune

In a recent paper, "Reexamining $f\left(R,T\right)$ gravity", by S. B. Fisher and E. D. Carlson, Phys. Rev. D 100, 064059 (2019), the authors claim that for the particular $f(R,T)$ modified gravity model, with $f(R,T)=f_1(R)+f_2(T)$, the…

广义相对论与量子宇宙学 · 物理学 2020-03-19 Tiberiu Harko , Pedro H. R. S. Moraes

The expansion of the universe in $f(R,T)$ gravity is studied. By focusing on functions of the form $f(R,T)=f_1(R)+f_2(T)$, we assert that present day acceleration can be achieved if the functional form of $f_2(T)$ either grows slowly or…

广义相对论与量子宇宙学 · 物理学 2025-02-05 Vincent R. Siggia , Eric D. Carlson

In a recent paper [1] (PRL 98,131302,2007) we have shown that f(R)=R + mu R^{n} modified gravity dark energy models are not cosmologically viable because during the matter era that precedes the accelerated stage the cosmic expansion is…

天体物理学 · 物理学 2008-11-26 Luca Amendola , David Polarski , Shinji Tsujikawa

This article deals with a cosmological scenario in $ f(R,T) $ gravity for a flat FLRW model of the universe. We consider the $ f(R,T) $ function as $ f(R)+f(T) $ which starts with a quadratic correction of the geometric term $ f(R) $ having…

广义相对论与量子宇宙学 · 物理学 2022-05-03 Ritika Nagpal , J. K. Singh , A. Beesham , Hamid Shabani

In this paper, we have considered a quadratic variation of the deceleration parameter ($q$) as a function of cosmic time ($t$) which describes a smooth transition from the decelerating phase of the Universe to an accelerating one and also…

广义相对论与量子宇宙学 · 物理学 2022-06-30 Ritika Nagpal , Shibesh Kumar Jas Pacif

In this paper, we explore the model of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity where the nonmetricity scalar $Q$ is non-minimally coupled to the trace of the energy-momentum tensor $T$. To ensure general covariance…

广义相对论与量子宇宙学 · 物理学 2025-09-09 Rahul Bhagat , Santosh V. Lohakare , B. Mishra

We review the status of $f(R,T)$ cosmological models, where $T$ is the trace of the energy momentum tensor $T^{\mu\nu}$. We start focusing on the modified Friedmann equations for the minimally coupled gravitational Lagrangian of the type…

宇宙学与河外天体物理 · 物理学 2024-03-08 Ana Paula Jeakel , Jonas Pinheiro da Silva , Hermano Velten

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…

综合物理 · 物理学 2018-11-14 M. Zubair , Saira Waheed , M. Atif Fayyaz , Iftikhar Ahmad

The expansion of the Universe in $f(R,T)$ gravity is studied. We consider functions of the form $f(R,T)=R+\lambda T^\epsilon$ where $\epsilon<1$. We find that for all models with $\epsilon<0$, the Universe transitions to exponential growth…

广义相对论与量子宇宙学 · 物理学 2026-03-26 Vincent R. Siggia , Eric D. Carlson , P. Lee Pryor

All $f(R)$ modified gravity theories are conformally identical to models of quintessence in which matter is coupled to dark energy with a strong coupling. This coupling induces a cosmological evolution radically different from standard…

天体物理学 · 物理学 2008-11-26 Luca Amendola , David Polarski , Shinji Tsujikawa

Harko and Moraes claim that in $f(R,T)$ gravity with $f(R,T)=f_1(R)+f_2(T)$, the term $f_2(T)$ cannot be incorporated in the matter Lagrangian ${\cal L}_m$. A careful examination of their Comment finds that they have made several dubious…

广义相对论与量子宇宙学 · 物理学 2020-06-24 Sarah B. Fisher , Eric D. Carlson

The problem of cosmic acceleration and dark energy is one of the mysteries presently posed in the scientific society that general relativity has not been able to solve. In this work, we have considered alternative models to explain this…

广义相对论与量子宇宙学 · 物理学 2022-12-01 M. Koussour , N. Myrzakulov , S. H. Shekh , M. Bennai

This thesis explores the late-time cosmic acceleration within the framework of $f(R,T)$ gravity, a general relativity modification that incorporates the Ricci scalar $R$ and the trace of the energy-momentum tensor $T$. Motivated by…

广义相对论与量子宇宙学 · 物理学 2025-07-29 Parbati Sahoo

In this article, we explore the comprehensive narrative of cosmic evolution within a cosmological framework by utilizing a novel form of gravity known as generalized symmetric teleparallel gravity, denoted as $f(Q,T)$ gravity. Here, $Q$…

综合物理 · 物理学 2024-09-10 Surajit Das , Sanjay Mandal

The basic aim of this manuscript is to investigate the cosmological solutions in the context of the modified $f(R, T)$ theory of gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor. For our current…

广义相对论与量子宇宙学 · 物理学 2024-03-26 Adnan Malik , Tayyaba Naz , Aimen Rauf , M. Farasat Shamir , Z. Yousaf

In this paper, we consider a theory of gravity with a metric-dependent torsion namely the $F(R,T)$ gravity, where $R$ is the curvature scalar and $T$ is the torsion scalar. We study a geometric root of such theory. In particular we give the…

广义相对论与量子宇宙学 · 物理学 2012-11-20 Ratbay Myrzakulov
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