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相关论文: Barotropic FRW cosmologies with a Dirac-like param…

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Assuming equation of state for quintessential matter: $p=w(z)\rho$, we analyse dynamical behaviour of the scale factor in FRW cosmologies. It is shown that its dynamics is formally equivalent to that of a classical particle under the action…

广义相对论与量子宇宙学 · 物理学 2009-11-10 Marek Szydlowski , Wojciech Czaja

In this work, we propose a new model that combines holographic dark energy with modified gravity $f(Q,T)$ to explore a possible explanation for the accelerated expansion of the universe. Since there are several tensions of cosmological…

宇宙学与河外天体物理 · 物理学 2025-07-08 Xuwei Zhang , Xiaofeng Yang , Yunliang Ren , Shuangnan Chen , Yangjun Shi , Cheng Cheng , Xiaolong He

Using a D = 1 supergravity framework I construct a super-Friedmann equation for an isotropic and homogenous universe including dynamical scalar fields. In the context of quantum theory this becomes an equation for a wave-function of the…

广义相对论与量子宇宙学 · 物理学 2019-02-12 J. W. van Holten

Redshift drift is the phenomenon whereby the observed redshift between an emitter and observer comoving with the Hubble flow in an expanding FLRW universe will slowly evolve -- on a timescale comparable to the Hubble time. In a previous…

广义相对论与量子宇宙学 · 物理学 2024-04-03 Francisco S. N. Lobo , José Pedro Mimoso , Jessica Santiago , Matt Visser

In this paper, we have presented the cosmological model of the Universe that represents late time cosmic acceleration in torsion based gravitational theory, the $f(T)$ gravity. A well motivated parametrization for the Hubble parameter has…

广义相对论与量子宇宙学 · 物理学 2025-11-04 Suraj Kumar Behera , Pratik P. Ray , B. Mishra

In the context of metric f(R) gravity, we consider a FLRW space-time, filled with a perfect fluid described by a barotropic equation of state (p = \gamma \rho). We give the equivalent mini-superspace description and use the…

广义相对论与量子宇宙学 · 物理学 2015-06-17 N. Dimakis , T. Christodoulakis , Petros A. Terzis

We obtain the analogues of the Friedman equations in an emergent gravity scenario in the presence of dark energy. The background metric is taken to be Friedman-Lemaitre-Robertson-Walker (FLRW). We show that if $\dot\phi ^{2}$ is the dark…

广义相对论与量子宇宙学 · 物理学 2015-02-24 Debashis Gangopadhyay , Goutam Manna

We consider a possible ways of the dynamics of a homogeneous and isotropic space described by the FLRW metric in the framework of cubic f(R) gravity in the absence of matter. This article points an method for limiting the parameters of…

广义相对论与量子宇宙学 · 物理学 2023-04-20 P. M. Petryakova

In this paper, we have presented the big rip and pseudo rip cosmological models in an extended theory of gravity. The matter field is considered to be that of perfect fluid. The geometrical parameters are adjusted in such a manner that it…

广义相对论与量子宇宙学 · 物理学 2022-07-19 Pratik P. Ray , Sankarsan Tarai , B. Mishra , S. K. Tripathy

The present paper reports a study on the cosmological consequences arising from reconstructing $f(T)$ gravity through new holographic-polytropic dark energy. We assume two approaches, namely a particular form of Hubble parameter $H$ and a…

广义相对论与量子宇宙学 · 物理学 2016-11-01 Surajit Chattopadhyay , Abdul Jawad , Shamaila Rani

In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…

广义相对论与量子宇宙学 · 物理学 2025-10-28 Archana Dixit , Manish Yadav , Anirudh Pradhan , M. S. Barak

We consider the influence of the perturbative bulk viscosity on the evolution of the Hubble parameter in the QCD era of the early Universe. For the geometry of the Universe we assume the homogeneous and isotropic…

广义相对论与量子宇宙学 · 物理学 2010-11-24 A. Tawfik , M. Wahba , H. Mansour , T. Harko

We studied plane symmetric cosmological model in the presence of quark and strange quark matter with the help of f(R,T) theory. To decipher solutions of Plane symmetric space-time, we used power law relation between scale factor and…

广义相对论与量子宇宙学 · 物理学 2017-03-22 P. K. Agrawal , D. D. Pawar

A cosmological model is proposed for the current Universe consisted of non-interacting baryonic matter and interacting dark components. The dark energy and dark matter are coupled through their effective barotropic indexes, which are…

天体物理学 · 物理学 2009-06-15 Luis P. Chimento , Monica Forte , Gilberto M. Kremer

In this manuscript, we investigate the patterns satisfied by the cosmological anisotropy under the hypothesis of the observers being co-moving with a perfect fluid whose induced space sections are homogeneous with vanishing scalar…

广义相对论与量子宇宙学 · 物理学 2021-03-31 Leandro G. Gomes

We study an isotropic flat FLRW-model in Scale-covariant theory of gravity $ f_{\gamma \delta}(\phi) $ \cite{Canuto:1977zz} which is explained in terms of ordinary and covariant differentiation of scalar field $ \phi $. As we know the…

广义相对论与量子宇宙学 · 物理学 2024-05-01 Shaily , J. K. Singh , Joao R. L. Santos , M. Zeyauddin

The cosmological application of a dark viscous fluid in a spatially flat Friedmann-Robertson-Walker (FRW) universe with a modified logarithmic equation of state (EoS), being an analogue of the equation associated with the isotropic…

广义相对论与量子宇宙学 · 物理学 2026-04-02 I. Brevik , A. V. Timoshkin

We study the quantum cosmology of a quadratic $f(R)$ theory with a FRW metric, via one of its equivalent Horndeski type actions, where the dynamics of the scalar field is induced. The classical equations of motion and the Weeler-deWitt…

广义相对论与量子宇宙学 · 物理学 2017-06-22 V. Vázquez-Báez , C. Ramírez

This paper explores models of the FLRW universe that incorporate a time-varying cosmological term $\Lambda(t)$. Specifically, we assume a power-law form for the cosmological term as a function of the scale factor: $\Lambda(t)=\Lambda_{0}…

宇宙学与河外天体物理 · 物理学 2024-05-14 M. Koussour , N. Myrzakulov , J. Rayimbaev

The observations of SNIa suggest that we live in the acceleration epoch when the densities of the cosmological constant term and matter are almost equal. This leads to the cosmic coincidence conundrum. As the explanation for this problem we…

天体物理学 · 物理学 2008-05-24 Marek Szydlowski