中文
相关论文

相关论文: Cosmological sudden singularities in $f(R,T)$ grav…

200 篇论文

This paper is devoted to investigate the exact solutions of Bianchi type $I$ spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an arbitrary function of Ricci scalar $R$ and trace of the energy momentum tensor $T$. For this…

广义相对论与量子宇宙学 · 物理学 2015-06-30 M. Farasat Shamir

In this paper, we investigate the late-time cosmic acceleration in mimetic $f(R,T)$ gravity with Lagrange multiplier and potential in a Universe containing, besides radiation and dark energy, a self-interacting (collisional) matter. We…

广义相对论与量子宇宙学 · 物理学 2017-11-22 E. H. Baffou , M. J. S. Houndjo , M. Hamani-Daouda , F. G. Alvarenga

Dynamical behavior and future singularities of $f(R, T,R_{\mu\nu}T^{\mu\nu})$ gravitational theory are investigated. This gravitational model is a more complete form of the $f(R,T)$ gravity which can offer new dynamics for the universe. We…

广义相对论与量子宇宙学 · 物理学 2020-04-06 Maryam Aghaei Abchouyeh , Behrouz Mirza , Parisa Shahidi , Fatemeh Oboudiat

We investigate a bounce realization in the framework of higher order curvature in $ f(R,T) $ modified theory of gravity. We perform a detailed analysis of the cosmological parameters to explain the contraction phase, the bounce phase, and…

广义相对论与量子宇宙学 · 物理学 2023-07-19 J. K. Singh , Shaily , Akanksha Singh , Aroonkumar Beesham , Hamid Shabani

The $f(T,T_G)$ class of gravitational modification, based on the quadratic torsion scalar $T$, as well as on the new quartic torsion scalar $T_G$ which is the teleparallel equivalent of the Gauss-Bonnet term, is a novel theory, different…

广义相对论与量子宇宙学 · 物理学 2014-08-19 Georgios Kofinas , Genly Leon , Emmanuel N. Saridakis

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…

广义相对论与量子宇宙学 · 物理学 2023-03-13 Simran Arora , Aaqid Bhat , P. K. Sahoo

We construct the energy conditions for the recently proposed $f(R,L,T)$ gravity theory, for which $f$ is a generic function of the Ricci scalar $R$, matter lagrangian density $L$ and trace of the energy-momentum tensor $T$. We analyse two…

广义相对论与量子宇宙学 · 物理学 2024-06-25 Simran Arora , P. H. R. S. Moraes , P. K. Sahoo

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

In this paper, we study the dynamical behaviour of the Universe in the $F(R,G)$ theory of gravity, where $R$ and $G$ respectively denote the Ricci scalar and Gauss-Bonnet invariant. Our wide analysis encompasses the energy conditions,…

广义相对论与量子宇宙学 · 物理学 2022-04-22 Santosh V. Lohakare , S. K. Tripathy , B. Mishra

Although $f(R)$ modification of late time cosmology is successful in explaining present cosmic acceleration, it is difficult to satisfy the fifth-force constraint simultaneously. Even when the fifth-force constraint is satisfied, the…

广义相对论与量子宇宙学 · 物理学 2015-09-09 Koushik Dutta , Sukanta Panda , Avani Patel

The variety of theories that can account for the dark energy phenomenon encourages current research to concentrate on a more in-depth examination of the potential impacts of modified gravity on both local and cosmic scales. We discuss some…

广义相对论与量子宇宙学 · 物理学 2023-01-27 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo

The paper deals with $f(R)$ gravity theory in the background of inhomogeneous FLRW--type space time model. With proper choice of the inhomogeneous metric function it is possible to have an emergent scenario for the $f(R)$--cosmology.…

广义相对论与量子宇宙学 · 物理学 2018-11-14 Dipanjana Das , Sourav Dutta , Subenoy Chakraborty

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 present a fully covariant and gauge-invariant analysis of linear cosmological perturbations in Energy-Momentum Squared Gravity. Working within the 1+3 formalism, we derive the exact propagation equations for scalar, vector, and tensor…

广义相对论与量子宇宙学 · 物理学 2025-11-10 Peter K. S. Dunsby , Maria-Alexia Caldis , Eduardo Bittencourt

Currently, in order to explain the accelerated expansion phase of the universe, several alternative approaches have been proposed, among which the most common are dark energy models and alternative theories of gravity. Although these…

广义相对论与量子宇宙学 · 物理学 2021-08-24 I. S. Farias , P. H. R. S. Moraes

We study $f(R,T)$ gravity, in which the curvature $R$ appearing in the gravitational Lagrangian is replaced by an arbitrary function of the curvature and the trace $T$ of the stress-energy tensor. We focus primarily on situations where $f$…

广义相对论与量子宇宙学 · 物理学 2019-10-02 Sarah B. Fisher , Eric D. Carlson

The main purpose of this paper is to investigate the exact solutions of cylindrically symmetric spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an arbitrary function of Ricci scalar $R$ and trace of the energy momentum…

广义相对论与量子宇宙学 · 物理学 2015-07-01 M. Farasat Shamir , Zahid Raza

We consider the fate of future singularities in the effective dynamics of loop quantum cosmology. Non-perturbative quantum geometric effects which lead to $\rho^2$ modification of the Friedmann equation at high energies result in generic…

广义相对论与量子宇宙学 · 物理学 2008-11-26 M. Sami , Parampreet Singh , Shinji Tsujikawa

We investigate the emergence of cosmic hysteresis in cyclic bouncing cosmologies within the framework of $f(R)$ modified gravity theories. Building upon previous studies that explored hysteresis phenomena in braneworld and…

广义相对论与量子宇宙学 · 物理学 2025-06-12 Aritra Sanyal

We demonstrate that finite time singularities of Type IV can be consistently incorporated in the Universe's cosmological evolution, either appearing in the inflationary era, or in the late-time regime. While using only one scalar field…

广义相对论与量子宇宙学 · 物理学 2015-12-02 Shin'ichi Nojiri , S. D. Odintsov , V. K. Oikonomou , Emmanuel N. Saridakis