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相关论文: Bounding f(R,T) gravity by particle creation

200 篇论文

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

In this paper we derive a novel cosmological model from the $f(R,T)$ theory of gravitation, for which $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor. We consider the functional form $f(R,T)=f(R)+f(T)$, with…

广义相对论与量子宇宙学 · 物理学 2019-06-04 P. H. R. S. Moraes , P. K. Sahoo , G. Ribeiro , R. A. C. Correa

In this paper, we first obtain the energy density by the approach of the new agegraphic dark energy model, and then the $f(T,B)$ gravity model is studied as an alternative to the dark energy in a viscous fluid by flat-FRW background, in…

广义相对论与量子宇宙学 · 物理学 2020-06-17 A. Pourbagher , Alireza Amani

An exact cosmological solution of Einstein field equations (EFEs) is derived for a dynamical vacuum energy in $f(R,T)$ gravity for Friedmann-Lemaitre-Robertson-Walker (FLRW) space-time. A parametrization of the Hubble parameter is used to…

综合物理 · 物理学 2018-11-22 Ritika Nagpal , S. K. J. Pacif , J. K. Singh , Kazuharu Bamba , A. Beesham

In this paper, we have studied the bouncing behavior of the cosmological models formulated at the background of the Hubble function in the F(R, G) theory of gravity, where R and G denote the Ricci scalar and Gauss-Bonnet invariant. The…

广义相对论与量子宇宙学 · 物理学 2022-12-02 Santosh V Lohakare , Francisco Tello-Ortiz , S. K. Tripathy , B. Mishra

We consider f(R,T) modified theories of gravity, where the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar R and of the trace of the stress-energy tensor T. We obtain the gravitational field equations in the…

广义相对论与量子宇宙学 · 物理学 2011-07-14 Tiberiu Harko , Francisco S. N. Lobo , Shin'ichi Nojiri , Sergei D. Odintsov

We are living in a golden age for experimental cosmology. New experiments with high accuracy precision are been used to constrain proposals of several theories of gravity, as it has been never done before. However, important roles to…

广义相对论与量子宇宙学 · 物理学 2021-02-18 Simran Arora , J. R. L. Santos , P. K. Sahoo

$f(R,T)$ gravity is a widely used extended theory of gravity introduced in \cite{9} which is a straightforward generalization of $f(R)$ gravity. The action in this extended theory of gravity incorporates well motivated functional forms of…

广义相对论与量子宇宙学 · 物理学 2020-07-09 Snehasish Bhattacharjee , P. K. Sahoo

In the context of f(R, T) gravity theory for the flat Friedmann Lemaitre Robertson Walker (FLRW) model, the accelerating expansion of the universe is investigated using a specific form of the emergent Hubble parameter. Datasets from H(z),…

广义相对论与量子宇宙学 · 物理学 2025-01-16 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , Archana Dixit

A bouncing scenario of a flat homogeneous and isotropic universe is explored by using the reconstruction technique for the power-law parametrization of the Hubble parameter in a modified gravity theory with higher-order curvature and trace…

广义相对论与量子宇宙学 · 物理学 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena

The $f(R,T)$ gravity is an extended theory of gravity in which the gravitational action contains general terms of both the Ricci scalar $R$ and trace of the energy-momentum tensor $T$. In this way, $f(R,T)$ models are capable of describing…

广义相对论与量子宇宙学 · 物理学 2017-07-20 P. H. R. S. Moraes , P. K. Sahoo

We extend the idea of unimodular gravity to the modified $f(R,T)$ theories. A new class of cosmological solutions, that the unimodular constraint on the metric imposes on the $f(R,T)$ theories, are studied. This extension is done in both…

广义相对论与量子宇宙学 · 物理学 2017-11-22 F. Rajabi , K. Nozari

We develop a method for computing the Bogoliubov transformation experienced by a confined quantum scalar field in a globally hyperbolic spacetime, due to the changes in the geometry and/or the confining boundaries. The method constructs a…

量子物理 · 物理学 2021-10-26 Luis C. Barbado , Ana L. Báez-Camargo , Ivette Fuentes

Teleparallel Gravity offers the possibility of reformulating gravity in terms of torsion by exchanging the Levi-Civita connection with the Weitzenb\"ock connection which describes torsion rather than curvature. Surprisingly, Teleparallel…

广义相对论与量子宇宙学 · 物理学 2020-07-23 Maria Caruana , Gabriel Farrugia , Jackson Levi Said

This paper is devoted in the study of the hydrostatic equilibrium of stellar structure in the framework of modified $f(R, T)$ gravity theory that allows the non-conservation of energy-momentum, with possible implications for several…

综合物理 · 物理学 2019-12-24 S. K. Maurya , Ayan Banerjee , Francisco Tello-Ortiz

In this work, we investigate the bouncing behavior of the universe within the framework of $f(R,L_m)$ gravity, using a simple form of $f(R,L_m)=\frac{R}{2}+L_m^\gamma$ (where $\gamma$ is a free model parameter) as previously studied. The…

广义相对论与量子宇宙学 · 物理学 2024-03-29 M. Koussour , N. Myrzakulov , Javlon Rayimbaev , Alnadhief H. A. Alfedeel , H. M. Elkhair

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…

广义相对论与量子宇宙学 · 物理学 2017-05-23 Hamid Shabani , Mehrdad Farhoudi

In this paper, we considered the study of Friedmann-Robertson-Walker (FRW) model in the framework of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity, recently defined by Y. Xu et al. \cite{Xu}. The non-linear model…

广义相对论与量子宇宙学 · 物理学 2021-05-05 Nisha Godani , Gauranga C Samanta

In this work, we investigate Big Bang Nucleosynthesis (BBN) within the framework of $f(T,{L}_m)$ gravity, where the gravitational Lagrangian is generalized as a function of the torsion scalar $T$ and the matter Lagrangian ${L}_m$. We…

宇宙学与河外天体物理 · 物理学 2025-09-25 Daniel F. P. Cruz , David S. Pereira , Francisco S. N. Lobo , José P. Mimoso

In the present article, we developed a dynamical system in the context of modified $f(R,G,T)$ gravity, where $R$, $G$ and $T$ are Ricci scalar, Gauss-Bonnet term and energy-momentum tensor respectively. Development of the dynamical system…

广义相对论与量子宇宙学 · 物理学 2025-05-30 Elangbam Chingkheinganba Meetei , S. Surendra Singh