English
Related papers

Related papers: Non-Singular Bouncing Model in Energy Momentum Squ…

200 papers

The aim of this paper is to reconstruct and analyze the stability of some cosmological models against linear perturbations in $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ represent the Gauss-Bonnet invariant and trace of the…

General Relativity and Quantum Cosmology · Physics 2017-06-22 M. Sharif , Ayesha Ikram

We study a theory of gravity of the form $f(\mathcal{G})$ where $\mathcal{G}$ is the Gauss-Bonnet topological invariant without considering the standard Einstein-Hilbert term as common in the literature, in arbitrary $(d+1)$ dimensions. The…

General Relativity and Quantum Cosmology · Physics 2020-01-30 Francesco Bajardi , Konstantinos F. Dialektopoulos , Salvatore Capozziello

This cosmological model is a study of modified $f(Q,T)$ theory of gravity which was recently proposed by Xu {\it et al.} (Eur. Phys. J. C {\bf 79}, 708 (2019)). In this theory of gravity, the action contains an arbitrary function $f(Q,T)$…

General Physics · Physics 2021-09-03 Anirudh Pradhan , Archana Dixit

Motivated by conventional gauge theories, we consider a theory of gravity in which the Einstein-Hilbert action is replaced by a term that is quadratic in the Riemann tensor. We focus on cosmological solutions to the field equations in flat,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. Lasenby , C. J. L. Doran , R. Heineke

In this work we have investigated the dynamics of a recent modification to the general theory of relativity, the energy-momentum squared gravity model $f(R,\mathbf{T^2})$, where $R$ represents the scalar curvature and $\mathbf{T^2}$ the…

General Relativity and Quantum Cosmology · Physics 2019-10-16 Sebastian Bahamonde , Mihai Marciu , Prabir Rudra

By applying Noether symmetry methods, analytic solutions are obtained for a generalized Einstein-scalar-Gauss-Bonnet model with a $\xi(\phi)f(G)$ component. Variation with respect to the metric, supplemented by small perturbations, produces…

General Relativity and Quantum Cosmology · Physics 2025-12-15 Olga Razina , Dauren Rakhatov , Pyotr Tsyba , Emilio Elizalde

We consider the cosmological implications of a four-dimensional extension of the Gauss-Bonnet $f(G)$ gravity, where $G$ is the Gauss-Bonnet topological invariant, in which the Einstein-Hilbert action is replaced by an arbitrary function…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Ratul Mandal , Himanshu Chaudhary , Tiberiu Harko , Ujjal Debnath , G. Mustafa

We explore the recently introduced modified Gauss-Bonnet gravity [1], $f(\mathcal{G},T)$ pragmatic with $\mathcal{G}$, the Gauss-Bonnet term, and ${T}$, the trace of the energy-momentum tensor. Noether symmetry approach has been used to…

General Physics · Physics 2017-01-31 M. Farasat Shamir , Mushtaq Ahmad

We construct a Born-Infeld-type $f(R,{\cal G})$ modification of gravity, where ${\cal G}$ is the Gauss-Bonnet term, by embedding Born-Infeld electrodynamics in a five-dimensional pure modified gravity. This method leads to the…

General Relativity and Quantum Cosmology · Physics 2026-04-30 Yermek Aldabergenov , Wei Lin , Rongjian Li , Ding Ding , Yidun Wan

A new four-parameters family of constitutive functions for spherically symmetric elastic bodies is introduced which extends the two-parameters class of polytropic fluid models widely used in several applications of fluid mechanics. The four…

Analysis of PDEs · Mathematics 2022-11-30 Simone Calogero

Nonlinear electrodynamics, which acts as a source of gravity Einstein field equations, leads to emergent cosmology, an alternative solution which can avoid Big Bang singularity. In this paper, we explore the emerging universe in models of…

General Relativity and Quantum Cosmology · Physics 2023-01-25 Payel Sarkar , Prasanta Kumar Das

The basic objective of this investigation is to explore the impact of a novel gravitational modification, specifically, the $f(\mathcal{G}, \mathbf{T}^2)$ (where $\mathbf{T}^2 \equiv T_{\alpha\beta}T^{\alpha\beta}$, $T^{\alpha\beta}$…

General Relativity and Quantum Cosmology · Physics 2022-04-12 Z. Yousaf , M. Z. Bhatti , S. Khan , P. K. Sahoo

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

The present paper is elaborated to discuss the energy condition bounds in a modified teleparallel gravity namely $F(T,T_{G})$, involving torsion invariant $T$ and contribution from a term $T_G$, the teleparallel equivalent of the…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Saira Waheed , M. Zubair

We explore the possibility of a consistent cosmology based on the gauge-fixing independent running of the gravitational and cosmological constants ($G$ and $\Lambda$) in the framework of effective quantum gravity. In particular, their…

General Relativity and Quantum Cosmology · Physics 2024-04-30 Nicolas R. Bertini , Davi C. Rodrigues , Ilya L. Shapiro

In this work we examine the internal structure of compact stars within an extended gravitational framework described by the function $f(\mathcal{R},\mathcal{G},\mathcal{T})$. Throughout this work, the quantity $\mathcal{R}$ refers to the…

General Relativity and Quantum Cosmology · Physics 2025-11-25 G. G. L. Nashed

We confront various nonsingular bouncing cosmologies with the recently released BICEP2 data and investigate the observational constraints on their parameter space. In particular, within the context of the effective field approach, we…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-19 Yi-Fu Cai , Jerome Quintin , Emmanuel N. Saridakis , Edward Wilson-Ewing

We study the dynamics of a homogeneous and isotropic Friedmann-Robertson-Walker universe in the context of the Eddington-inspired Born-Infeld theory of gravity. We generalize earlier results, obtained in the context of a radiation dominated…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-16 P. P. Avelino , R. Z. Ferreira

We analyse the gravitational behaviour of a relativistic heat conducting fluid in a shear-free spherically symmetric spacetime. We show that the isotropy of pressure is a consistency condition which realises a second order nonlinear…

General Relativity and Quantum Cosmology · Physics 2015-12-31 B. P. Brassel , S. D. Maharaj , G. Govender

In this paper, we consider an open system from the thermodynamic perspective for an adiabatic FRW universe model in which particle creation occurs within the system. In that case, the modified continuity equation is obtained and then we…

General Relativity and Quantum Cosmology · Physics 2022-12-14 S. Ganjizadeh , Alireza Amani , M. A. Ramzanpour