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相关论文: A Quadratic Equation of State to Cosmic Accelerati…

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We investigate the cosmological implications of a generalized total equation of state (EoS) model by constraining its parameters using observational datasets to effectively characterize the universe's expansion history and its dynamic…

宇宙学与河外天体物理 · 物理学 2025-01-14 M. Koussour , S. Bekov , A. Syzdykova , S. Muminov , I. Ibragimov , J. Rayimbaev

The dark energy universe equation of state (EOS) with inhomogeneous,Hubble parameter dependent term is considered. The motivation to introduce such a term comes from time-dependent viscosity considerations and modifications of general…

高能物理 - 理论 · 物理学 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We investigate the general relativistic dynamics of Robertson-Walker models with a non-linear equation of state (EoS), focusing on the quadratic case P = P_0 + \alpha \rho + \beta \rho^2. This may be taken to represent the Taylor expansion…

天体物理学 · 物理学 2008-12-18 Kishore N. Ananda , Marco Bruni

The time evolution of cosmological parameters in early Universe at the deconfinement transition is studied by an equation of state (EoS) which takes into account the finite baryon density and the background magnetic field. The non…

高能物理 - 唯象学 · 物理学 2015-09-30 Paolo Castorina , Vincenzo Greco , Salvatore Plumari

In this study, we introduce a novel late-time effective dark energy model characterized by a quadratic equation of state (EoS) and rigorously examine its observational constraints. Initially, we delve into the background dynamics of this…

宇宙学与河外天体物理 · 物理学 2024-06-11 Hossein Moshafi , Alireza Talebian , Ebrahim Yusofi , Eleonora Di Valentino

In the symmetric teleparallel gravity framework, we study the cosmic dynamics of the universe with dark energy equation of state (EoS) parameter having non-linear forms. The non-metricity scalar induced by the dark energy EoS parameter…

广义相对论与量子宇宙学 · 物理学 2025-07-10 Romanshu Garg , G. P. Singh , Ashutosh Singh

We explore the cosmological evolution of equation of state (EoS) for dark energy in g-essence models, the action of which is described by a function of both the canonical kinetic term of both the scalar and fermionic fields. We examine…

综合物理 · 物理学 2013-05-06 Kazuharu Bamba , Olga Razina , Koblandy Yerzhanov , Ratbay Myrzakulov

Evolution of cosmological perturbations is considered in the model with dynamical dark energy which non-gravitationally interacts with dark matter. The dark energy equation of state parameter (EoS) is varying in time and is parameterized by…

宇宙学与河外天体物理 · 物理学 2020-11-09 R. Neomenko , B. Novosyadlyj

We present the cosmic expansion scenario in the framework of $f(T)$ gravity by employing a dark energy equation of state (EoS) parameter. Specifically, we proceed with the power-law form of the function $f(T) = \alpha$$(-T)^{n}$, in…

广义相对论与量子宇宙学 · 物理学 2026-04-21 Khomesh R. Patle , G. P. Singh

Recent analysis of the DESI Collaboration challenges the $\Lambda$-Cold Dark Matter ($\Lambda$CDM) model, suggesting evidence for a dynamic dark energy. These results are obtained in the context of generic parameterizations of the dark…

宇宙学与河外天体物理 · 物理学 2025-10-21 Rayff de Souza , Gabriel Rodrigues , Jailson Alcaniz

We explore the equation of state (EoS) for dark energy $w_{\mathrm{DE}}$ in modified gravitational theories to explain the current accelerated expansion of the universe. We explicitly demonstrate that the future crossings of the phantom…

广义相对论与量子宇宙学 · 物理学 2017-08-23 Kazuharu Bamba

Scenarios of cosmological evolution having inflationary stages are studied by using equations of state (EoS) inspired by the quark bag model. A crucial point is the existence of states where the specific enthalpy of the cosmological fluid…

宇宙学与河外天体物理 · 物理学 2014-07-30 L. L. Jenkovszky , V. I. Zhdanov , E. J. Stukalo

The equation of state (EOS) in quartessence models interpolates between two stages: $p\simeq 0$ at high energy densities and $p\approx -\rho$ at small ones. In the quartessence models analyzed up to now, the EOS is convex, implying…

天体物理学 · 物理学 2009-11-11 L. Amendola , M. Makler , R. R. R. Reis , I. Waga

The dynamical aspect of accelerating cosmological model has been studied in this paper in the context of modified symmetric teleparallel gravity, the $f(Q)$ gravity. Initially, we have derived the dynamical parameters for two well known…

广义相对论与量子宇宙学 · 物理学 2023-07-18 S. A. Narawade , Shashank P. Singh , B. Mishra

Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology…

天体物理学 · 物理学 2009-07-09 E. M. Barboza , J. S. Alcaniz

We investigate the cosmic acceleration and the evolution of dark energy across the cosmological constant boundary in universal extra dimensions UED. We adopt an empirical approach to solve the higher-dimensional cosmological equations so…

广义相对论与量子宇宙学 · 物理学 2020-05-27 Nasr Ahmed , Anirudh Pradhan

This paper highlights cosmologically viable sine and cosine hyperbolic evolution functions in the framework of $f(Q,\mathcal{L}_m)$ gravity. The models have been tested to check the behavior of the equation of state (EoS) parameter under…

广义相对论与量子宇宙学 · 物理学 2026-02-02 V. A. Kshirsagar , S. A. Kadam , Vishwajeet S. Goswami

We suggest to generalize the dark energy equation of state (EoS) by introduction the relaxation equation for pressure which is equivalent to consideration of the inhomogeneous EoS cosmic fluid which often appears as the effective model from…

高能物理 - 理论 · 物理学 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

We construct cosmological model in nonmetricity scalar functional gravitational Lagrangian $f(Q)$ which describes the dynamical evolution of the late accelerating universe. Cosmological models are constructed considering different…

广义相对论与量子宇宙学 · 物理学 2025-04-23 Bikash Chandra Roy , Aroonkumar Beesham , Bikash Chandra Paul

A thermodynamic description of cosmological spacetimes may provide insights into the fundamentals of the cosmic evolution that remain otherwise obscure, similar to `black hole thermodynamics'. We investigate the thermodynamic properties of…

广义相对论与量子宇宙学 · 物理学 2026-03-31 Dipayan Mukherjee , Harkirat Singh Sahota , Swati Gavas
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