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相关论文: Modified Gauss-Bonnet Gravity with Radiating Fluid…

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The possible emergence of compact stars has been investigated in the recently introduced modified Gauss-Bonnet $f(\mathcal{G},T)$ gravity, where $\mathcal{G}$ is the Gauss-Bonnet term and ${T}$ is the trace of the energy-momentum tensor.…

广义相对论与量子宇宙学 · 物理学 2017-10-18 M. Farasat Shamir , Mushtaq Ahmad

In this paper, the quasi static-approximation on the hydrodynamics of compact objects is proposed in $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of stress-energy tensor, by exploring the axial and reflection…

广义相对论与量子宇宙学 · 物理学 2024-08-26 Z. Yousaf , Kazuharu Bamba , M. Z. Bhatti , U. Farwa

This work deals with the computation of the power spectrum of large-scale structure using the dynamical system approach for a multi-fluid universe in scalar-tensor theory of gravity. We use the $1+3$ covariant approach to obtain evolution…

广义相对论与量子宇宙学 · 物理学 2022-08-31 Joseph Ntahompagaze , Amare Abebe , Manasse R. Mbonye

In an $n$-dimensional Friedmann-Robertson-Walker metric, it is rigorously shown that any analytical theory of gravity $f(R,{\cal G})$, where $R$ is the curvature scalar and $\cal G$ is the Gauss-Bonnet topological invariant, can be…

广义相对论与量子宇宙学 · 物理学 2019-10-02 Salvatore Capozziello , Carlo Alberto Mantica , Luca Guido Molinari

The general relativistic perturbations of scalar-tensor theories (STT) of gravity are studied in a manifestly gauge invariant Hamiltonian formalism. After the derivation of the Hamiltonian equations of motion in this framework, the gauge…

广义相对论与量子宇宙学 · 物理学 2015-06-08 Yu Han , Kristina Giesel , Yongge Ma

This work is concerned to study the bouncing nature of the universe for an isotropic configuration of fluid $\mathcal{T}_{\alpha\beta}$ and Friedmann-Lema\^{i}tre-Robertson-Walker metric scheme. This work is carried out under the novel…

广义相对论与量子宇宙学 · 物理学 2023-02-08 Z. Yousaf , M. Z. Bhatti , H. Aman , P. K. Sahoo

Scalar-tensor gravity is the simplest and best understood modification of general relativity, consisting of a real scalar field coupled directly to the Ricci scalar curvature. Models of this type have self-accelerating solutions. In an…

天体物理学 · 物理学 2009-09-17 Gabriela Barenboim , Joseph Lykken

In recent few years, the Gauss-Bonnet $f(\mathcal{G},\mathrm{\textit{T}})$ theory of gravity has fascinated considerable researchers owing to its coupling of trace of the stress-energy tensor $T$ with the Gauss-Bonnet term $\mathcal{G}$. In…

广义相对论与量子宇宙学 · 物理学 2023-04-14 Mushtaq Ahmad , M. Farasat Shamir , G. Mustafa

We investigate the first and second order cosmological perturbation equations in f(R) modified gravity theory and provide the equation of motion of second order scalar induced gravitational waves. We find that the effects of modified…

广义相对论与量子宇宙学 · 物理学 2024-11-14 Jing-Zhi Zhou , Yu-Ting Kuang , Di Wu , Fei-Yu Chen , H. Lü , Zhe Chang

We study effects of cosmic fluids on finite-time future singularities in modified $f(R,G)$-gravity, where $R$ and $G$ are the Ricci scalar and the Gauss-Bonnet invariant, respectively. We consider the fluid equation of state in the general…

广义相对论与量子宇宙学 · 物理学 2010-11-15 Olesya Gorbunova , Lorenzo Sebastiani

In this paper we show how the covariant gauge invariant equations for the evolution of scalar, vector and tensor perturbations for a generic $f(R)$-gravity theory can be recast in order to exploit the power of dynamical system methodology.…

天体物理学 · 物理学 2008-12-12 Sante Carloni , Kishore N. Ananda , Peter K. S. Dunsby , Mohamed E. S. Abdelwahab

One of the possible potential candidates for describing the universe's rapid expansion is modified gravity. In the framework of the modified theory of gravity $f(R,G)$, the present work features the materialization of anisotropic matter,…

广义相对论与量子宇宙学 · 物理学 2022-06-29 W. U. Rahman , M. Ilyas , Z. Yousaf , S. Ullah , F. Khan , R. khan

In this paper, we explore the source of gravitational radiation in the context of $f(R)$ gravity by considering axially symmetric dissipative dust under geodesic condition. We evaluate scalars associated with electric and magnetic parts of…

广义相对论与量子宇宙学 · 物理学 2017-03-08 M. Sharif , Aisha Siddiqa

This manuscript aims to establish the gravitational junction conditions(JCs) for the $f(\mathcal{G},~T)$ gravity. In this gravitational theory, $f$ is an arbitrary function of Gauss-Bonnet invariant $\mathcal{G}$ and the trace of the…

广义相对论与量子宇宙学 · 物理学 2022-07-14 M. Z. Bhatti , Z. Yousaf , M. Yousaf

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 $\mathbf{T}^2 \equiv T_{\alpha\beta}T^{\alpha\beta}$, $T^{\alpha\beta}$…

广义相对论与量子宇宙学 · 物理学 2022-04-12 Z. Yousaf , M. Z. Bhatti , S. Khan , P. K. Sahoo

The Gauss-Bonnet invariant connects foundational aspects of geometry with physical phenomena in a variety of ways. Teleparallel gravity offers a novel direction in which to use the Gauss-Bonnet invariant to go beyond standard cosmology. In…

广义相对论与量子宇宙学 · 物理学 2026-04-21 Shivam Kumar Mishra , Jackson Levi Said , B. Mishra

This paper is devoted to investigate the recently proposed modified Gauss-Bonnet $f(\mathcal{G},T)$ gravity, with $\mathcal{G}$, the Gauss-Bonnet term, coupled with ${T}$, the trace of energy-momentum tensor. We have used the Noether…

广义相对论与量子宇宙学 · 物理学 2017-07-12 M. Farasat Shamir , Mushtaq Ahmad

Recent findings from the Neutron Star Interior Composition Explorer (NICER) have opened up opportunities to investigate the potential coupling between matter and geometry, along with its resulting physical implications. Millisecond pulsars…

广义相对论与量子宇宙学 · 物理学 2023-06-21 G. G. L. Nashed

Modified gravity theories on cosmic scales have three key deviations from general relativity. They can cause cosmic acceleration without a physical, highly negative pressure fluid, can cause a gravitational slip between the two metric…

宇宙学与河外天体物理 · 物理学 2014-11-04 Eric V. Linder

We analyze a fully geometric approach to dark energy in the framework of $F(R,{\cal G})$ theories of gravity, where $R$ is the Ricci curvature scalar and ${\cal G}$ is the Gauss-Bonnet topological invariant. The latter invariant naturally…

广义相对论与量子宇宙学 · 物理学 2020-11-09 Micol Benetti , Simony Santos da Costa , Salvatore Capozziello , Jailson S. Alcaniz , Mariafelicia De Laurentis