中文
相关论文

相关论文: Stability of Modified Gravity Coupled by the Weyl …

200 篇论文

In this study, FRW cosmology in modified gravity containing arbitrary function $f(R)$ is taken into consideration when our action are coupled with Weyl tensor. It is indicated that the bouncing solution emerges in the model while the…

综合物理 · 物理学 2015-03-31 Mohammad Ghanaatian , Farzad Milani

Within the context of modified gravity and dark energy scenarios of the accelerating universe, we study the stability of de Sitter space with respect to inhomogeneous perturbations using a gauge-independent formalism. In modified gravity…

广义相对论与量子宇宙学 · 物理学 2009-11-11 Valerio Faraoni

Conditions for the existence and stability of de Sitter space in modified gravity are derived by considering inhomogeneous perturbations in a gauge-invariant formalism. The stability condition coincides with the corresponding condition for…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Valerio Faraoni , Shahn Nadeau

In this study, we explore the dynamics of the universe using a modified gravity model represented by $f(R, G, T)$, where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet invariant, and $T$ is the trace of the stress-energy tensor. The model…

广义相对论与量子宇宙学 · 物理学 2025-03-27 Farzad Milani

In this paper, I consider a $f(R, G, T)$ modified gravity model where $R$ represents the Ricci scalar, $G$ denotes the Gauss-Bonnet invariant, and $T$ signifies the trace of the stress-energy tensor. This model is coupled with two distinct…

广义相对论与量子宇宙学 · 物理学 2024-09-04 Farzad Milani

In the present paper, we investigate constrained transit cosmological models in the most recent proposed modified gravity theory, $f(R,L_{m},T)$-gravity. We obtain the modified field equations for a flat homogeneous and isotropic…

广义相对论与量子宇宙学 · 物理学 2024-12-20 Dinesh Chandra Maurya

We use a modified Einstein-Maxwell gravity to study stability of an electrostatic spherical star. Correction terms in this model are scalers which are made from contraction of Ricci tensor and electromagnetic vector potential. Our…

广义相对论与量子宇宙学 · 物理学 2023-12-05 Hossein Ghaffarnejad , Tohid Ghorbani , Firoozeh Eidizadeh

We present a thorough stability analysis of modified gravity theories in the presence of matter fields. We use the Effective Field Theory framework for Dark Energy and Modified Gravity to retain a general approach for the gravity sector and…

广义相对论与量子宇宙学 · 物理学 2017-03-14 Antonio De Felice , Noemi Frusciante , Georgios Papadomanolakis

In this paper, we have considered flat Friedmann-Lema\^{i}tre-Robertson-Walker metric in the framework of perfect fluid models and modified $f(G)$ gravity (where $G$ is the Gauss Bonnet invariant). Particularly, we have considered…

广义相对论与量子宇宙学 · 物理学 2017-08-08 Kazuharu Bamba , M. Ilyas , M. Z. Bhatti , Z. Yousaf

A novel function for modified gravity is proposed, $f(R, T)=R+\lambda R^2+2\beta\ln(T)$, with constants $\lambda$ and $\beta$, scalar curvature $R$, and the trace of stress energy tensor $T$, satisfying $T=\rho-3p>0$. Subsequently, two…

综合物理 · 物理学 2020-06-16 Emilio Elizalde , Nisha Godani , Gauranga C. Samanta

In this paper, we have investigated the physical behavior of cosmological models in the framework of modified Teleparallel gravity. This model is established using a Renyi holographic ``dark energy model (RHDE) with a Hubble cutoff. Here we…

广义相对论与量子宇宙学 · 物理学 2023-01-11 Vinod Kumar Bhardwaj , Archana Dixit , Anirudh Pradhan , Symala Krishannair

We study FRW cosmology for a double scalar - tensor theory of gravity where two scalar fields are nonminimally coupled to the geometry. In a framework to study stability and attractor solutions of the model in the phase space, we constraint…

综合物理 · 物理学 2015-06-03 H. Farajollahi , A. Shahabi , A. Salehi

In this paper, we study $F(R)$ gravity by Hu-Sawicki model in Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) background. The Friedmann equations are calculated by modified gravity action, and then the obtained Friedmann equations are…

广义相对论与量子宇宙学 · 物理学 2016-05-25 Ali R. Amani

In this paper, we have studied the dynamical aspects of the cosmological model of the Universe in the Weyl type $f(Q,T)$ gravity, which is an extension of symmetric teleparallel gravity. The non-metricity scalar $Q$ has been expressed in…

广义相对论与量子宇宙学 · 物理学 2023-06-02 Rahul Bhagat , S. A. Narawade , B. Mishra

This paper is devoted to examining cosmological bouncing scenarios in the framework of the recently proposed symmetric teleparallel gravity (or $f(Q)$ gravity), where the non-metricity scalar $Q$ represents the gravitational interaction. We…

宇宙学与河外天体物理 · 物理学 2024-09-17 M. Koussour , N. Myrzakulov

The discovery of apparent cosmological acceleration has spawned a huge number of dark energy and modified gravity theories. The f(R) models of gravity are obtained when one replaces the Ricci scalar in the Einstein-Hilbert action by an…

广义相对论与量子宇宙学 · 物理学 2016-02-08 Boris Bolliet , Richard A. Battye , Jonathan A. Pearson

In this article, the bulk viscosity is introduced in a modified gravity model. The gravitational action has a general $f(R,T)$ form, where $R$ and $ T $ are the curvature scalar and the trace of energy momentum tensor respectively. An…

广义相对论与量子宇宙学 · 物理学 2020-10-02 Simran Arora , Xin-he Meng , S. K. J. Pacif , P. K. Sahoo

In this paper, working in a Friedman-Lemaitre-Robertson-Walker (FLRW), first, in the flat case, we recover the generalized Friedman equation of Quantum Loop cosmology, and therefore the cosmological bounce, in the framework of modified…

广义相对论与量子宇宙学 · 物理学 2021-01-20 Alessandro Casalino , Bruno Sanna , Lorenzo Sebastiani , Sergio Zerbini

In this paper we consider FRW cosmology in modified gravity which contain arbitrary functions $f(\phi)$. It is shown that the bouncing solution appears in the model whereas the equation of state (EoS) parameter crosses the phantom divider.…

广义相对论与量子宇宙学 · 物理学 2011-06-09 H. Farajollahi , F. Milani

We investigate the evolution of non vacuum Friedmann-Lema\^itre-Robertson-Walker (FLRW) with any spatial curvature in the context of Gauss-Bonnet gravity. The analysis employs a new method which enables us to explore the phase space of any…

广义相对论与量子宇宙学 · 物理学 2017-09-13 Sante Carloni , José P. Mimoso
‹ 上一页 1 2 3 10 下一页 ›