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相关论文: Generic feature of future crossing of phantom divi…

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We investigate the validity of cosmological models with an oscillating scale factor in relation to late-time cosmological observations. We show that these models not only meet the required late time observational constraints but can also…

广义相对论与量子宇宙学 · 物理学 2023-05-31 Mohit K. Sharma , Shibesh Kumar Jas Pacif , Gulmira Yergaliyeva , Kuralay Yesmakhanova

In this work we consider a family of cosmological models featuring future singularities. This type of cosmological evolution is typical of dark energy models with an equation of state violating some of the standard energy conditions (e.g.…

广义相对论与量子宇宙学 · 物理学 2016-12-21 Jose Beltran Jimenez , Ruth Lazkoz , Diego Saez-Gomez , Vincenzo Salzano

We have probed a cosmological model in $f(R)$-gravity, which is a cubic equation in scalar curvature $R$. The terms arise due to nonlinear $f(R)$ function are treated as energy due to curvature inspired geometry. As a result, we find…

广义相对论与量子宇宙学 · 物理学 2023-05-03 G. K. Goswami , Rita Rani , Harshna Balhara , J. K. Singh

Despite the significant accomplishments of general relativity, numerous unresolved issues persist in our understanding of the cosmos. One of the most perplexing challenges is the ongoing accelerated expansion of the Universe, which…

宇宙学与河外天体物理 · 物理学 2023-11-22 M. Koussour , N. Myrzakulov , Alnadhief H. A. Alfedeel , Amare Abebe

We study thermodynamics of the apparent horizon in $F(R)$ gravity. In particular, we demonstrate that a $F(R)$ gravity model with realizing a crossing of the phantom divide can satisfy the second law of thermodynamics in the effective…

高能物理 - 理论 · 物理学 2009-09-28 Kazuharu Bamba , Chao-Qiang Geng

In view of late-time cosmic acceleration, a dark energy cosmological model is revisited wherein Einstein's cosmological constant is considered as a candidate of dark energy. Exact solution of Einstein field equations (EFEs) is derived in a…

广义相对论与量子宇宙学 · 物理学 2019-11-22 S. K. J. Pacif , Md Salahuddin Khan , L. K. Paikroy , Shalini Singh

We present a comprehensive phase-space analysis of a quadratic dark energy model where the pressure includes a nonlinear term proportional to the square of the energy density. This minimal extension beyond the $\Lambda$CDM framework…

宇宙学与河外天体物理 · 物理学 2026-05-19 Sahar Mohammadi , Ebrahim Yusofi , Kosar Asadi

We propose a new dark energy (DE) model from four parameter generalized entropy function of apparent horizon in a spatially flat universe. Such kind of generalized entropy is able to generalize all the known entropies proposed so far, for…

广义相对论与量子宇宙学 · 物理学 2025-07-22 Priyanka Adhikary , Sudipta Das , Sergei D. Odintsov , Tanmoy Paul

By choosing the future event horizon as the horizon of the flat FLRW universe, we show that although the interacting holographic dark energy model is able to explain the phantom divide line crossing, but the thermodynamics second law is not…

广义相对论与量子宇宙学 · 物理学 2010-10-27 H. Mohseni Sadjadi

Two parameters scale factor leading to bouncing cosmology is considered. We show that at some model parameters we obtain the deceleration parameter $q_0\approx -0.535$ at the current epoch which is in agreement with the Planck data. The…

综合物理 · 物理学 2026-05-18 S. I. Kruglov

This paper investigates the cosmological implications of the modified gravity framework known as $f(R,\Sigma, T)$ gravity, focusing on its potential to unify and extend current cosmological models. The theory, introduced by Bakry and…

广义相对论与量子宇宙学 · 物理学 2025-03-04 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan

In earlier papers we showed that a frame dependent effective action motivated by the postulates of three-space general coordinate invariance and Weyl scaling invariance exactly mimics a cosmological constant in Friedmann-Robertson-Walker…

宇宙学与河外天体物理 · 物理学 2020-08-25 Stephen L. Adler

In this paper, we investigate the validity of the generalized second law (GSL) of thermodynamics in flat FRW chameleon cosmology where the boundary of the universe is assumed to be enclosed by the dynamical apparent horizon. It has been…

广义相对论与量子宇宙学 · 物理学 2015-05-28 H. Farajollahi , A. Salehi , F. Tayebi

In this paper we study cosmological application of holographic dark energy density in the modified gravity framework. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in…

高能物理 - 理论 · 物理学 2010-11-11 M. R. Setare

Within the limits of the present cosmological observations in f(R,T) gravity theory, we have analyzed a spherically symmetric space-time in 5D setting. The field equations have been carefully studied considering reasonable cosmological…

广义相对论与量子宇宙学 · 物理学 2020-10-28 Pheiroijam Suranjoy Singh , Kangujam Priyokumar Singh

We construct a new cosmological holographic dark energy scenario based on Loop Quantum Gravity inspired entropy, instead of the standard Bekenstein-Hawking one. The former is an extended black-hole entropy that arises from non-extensive…

广义相对论与量子宇宙学 · 物理学 2023-10-03 Andreas Lymperis

We present modified cosmological scenarios that arise from the application of the "gravity-thermodynamics" conjecture, using the Barrow entropy instead of the usual Bekenstein-Hawking one. The former is a modification of the black hole…

广义相对论与量子宇宙学 · 物理学 2020-07-22 Emmanuel N. Saridakis

We deepen the analysis of the cosmological acceleration produced by quantum gravity dynamics in the formalism of group field theory condensate cosmology, treated at the coarse-grained level via a phenomenological model, in the language of…

广义相对论与量子宇宙学 · 物理学 2025-06-19 Daniele Oriti , Xiankai Pang

An interacting dark energy model with interaction term $Q= \lambda_m H\rho_m+\lambda_dH\rho_d$ is considered. By studying the model near the transition time, in which the system crosses the w=-1 phantom-divide-line, the conditions needed to…

广义相对论与量子宇宙学 · 物理学 2008-11-26 H. Mohseni Sadjadi , M. Alimohammadi

A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of the…

广义相对论与量子宇宙学 · 物理学 2018-07-04 J. K. Singh , Kazuharu Bamba , Ritika Nagpal , S. K. J. Pacif