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

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Modified gravity theories with the Gauss-Bonnet term $G=R^2-4R^{\mu\nu}R_{\mu\nu}+R^{\mu\nu\rho\sigma}R_{\mu\nu\rho\sigma}$ have recently gained a lot of attention as a possible explanation of dark energy. We perform a thorough phase space…

广义相对论与量子宇宙学 · 物理学 2010-10-01 Shuang-Yong Zhou , Edmund J. Copeland , Paul M. Saffin

We consider a scenario of large-scale modification of gravity that does not invoke extra degrees of freedom but includes coupling between baryonic matter and dark matter in the Einstein frame. The total matter energy density follows the…

广义相对论与量子宇宙学 · 物理学 2022-11-23 Mayukh R. Gangopadhyay , Shibesh K. Jas Pacif , M. Sami , Mohit K. Sharma

We investigate various dark energy models by taking into account the thermal effects induced from Hawking radiation on the apparent horizon of the Universe, for example near a finite-time future singularity. If the dark energy density…

广义相对论与量子宇宙学 · 物理学 2021-02-17 Artyom V. Astashenok , Sergei D. Odintsov , Vasilis K. Oikonomou

In this paper, we first obtain the energy density by the approach of the new agegraphic dark energy model, and then the $f(T,B)$ gravity model is studied as an alternative to the dark energy in a viscous fluid by flat-FRW background, in…

广义相对论与量子宇宙学 · 物理学 2020-06-17 A. Pourbagher , Alireza Amani

One of the main aims in the next generation of precision cosmology experiments will be an accurate determination of the equation of state (EOS) for the dark energy (DE). If the latter is dynamical, the resulting barotropic index \omega…

天体物理学 · 物理学 2009-11-13 Joan Sola , Hrvoje Stefancic

We consider late-time cosmology in a (phantom) scalar-tensor theory with an exponential potential, as a dark energy model with equation of state parameter close to -1 (a bit above or below this value). Scalar (and also other kinds of)…

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

Within the framework of spatially covariant theories, we propose a general model for dark energy (DE) in which the cosmological background and perturbations are independently controlled by different sets of coefficients, and the equation of…

广义相对论与量子宇宙学 · 物理学 2025-08-05 Zhibang Yao , Gen Ye , Alessandra Silvestri

We investigate the oscillating effective equation of state (EoS) of the universe around the phantom divide in the framework of $F(R)$ gravity. We illustrate the behavior of $F(R)$ with realizing multiple crossings of the phantom divide.

宇宙学与河外天体物理 · 物理学 2014-11-20 Kazuharu Bamba , Chao-Qiang Geng

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and keeps positive has been explored in a specific $f(R,T)$ gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological…

广义相对论与量子宇宙学 · 物理学 2019-02-11 Nasr Ahmed , Sultan Z. Alamri

We discuss the modified gravity which includes negative and positive powers of the curvature and which provides the gravitational dark energy. It is shown that in GR plus the term containing negative power of the curvature the cosmic…

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

In this work we present a further investigation about Teleparallel Gravity Cosmology. We demonstrate that according the current astrophysical data (CC+Pantheon+BAO samplers with late universe measurements SH0ES+H0LiCOW), an $f(T,B)$ theory…

广义相对论与量子宇宙学 · 物理学 2021-05-07 Celia Escamilla-Rivera , Jackson Levi Said

We study the cosmological implications of barotropic fluid satisfying affine equation of state (EoS) in the General relativity and $f(Q)$ gravity framework. We describe the impact of affine EoS on the cosmic evolution in the model and…

广义相对论与量子宇宙学 · 物理学 2026-03-10 Romanshu Garg , G. P. Singh , Ashutosh Singh

We consider models where the dilaton, seen as the pseudo-Goldstone boson of broken scale invariance, plays the role of dark energy. We revisit Weinberg's theorem and show that quantum corrections induced by the graviton lead to the…

宇宙学与河外天体物理 · 物理学 2025-07-23 Philippe Brax

We investigate the cosmological dynamics of FHDE within $f(T)$ gravity by employing the dynamical system approach in a spatially flat FRW background. By introducing appropriate dimensionless variables, the field equations are reformulated…

广义相对论与量子宇宙学 · 物理学 2026-02-23 Elangbam Chingkheinganba Meetei , S. Surendra Singh

In this paper, we investigate the behavior of equation of state parameter and energy density for dark energy in the framework of f(T) gravity. For this purpose, we use anisotropic LRS Bianchi type I universe model. The behavior of…

广义相对论与量子宇宙学 · 物理学 2015-06-15 M. Sharif , Sehrish Azeem

A new class of FLRW cosmological models with time-evolving fundamental parameters should emerge naturally from a description of the expansion of the universe based on the first principles of quantum field theory and string theory. Within…

宇宙学与河外天体物理 · 物理学 2011-08-09 Javier Grande , Joan Sola , Spyros Basilakos , Manolis Plionis

Two $F(R)$ gravity models are tested on the basis of their viability during all stages of cosmological evolution. It is shown that these models can describe both the early-time inflationary epoch and the dark energy epoch. The models are…

广义相对论与量子宇宙学 · 物理学 2026-02-10 S. D. Odintsov , V. K. Oikonomou , G. S. Sharov

We use dynamical system methods to explore the general behaviour of $f(T)$ cosmology. In contrast to the standard applications of dynamical analysis, we present a way to transform the equations into a one-dimensional autonomous system,…

广义相对论与量子宇宙学 · 物理学 2018-03-14 A. Awad , W. El Hanafy , G. G. L. Nashed , Emmanuel N. Saridakis

DESI observations of baryon acoustic oscillations (BAOs), combined with cosmic microwave background (CMB) and type-Ia supernova (SN Ia) data, suggest that the dark energy equation of state $w_{\rm DE}$ crosses the phantom divide from…

宇宙学与河外天体物理 · 物理学 2026-02-03 Shinji Tsujikawa

We investigate the corresponding relation between $f(R)$ gravity and an interacting holographic dark energy. By obtaining conditions needed for some observational evidence such as, positive acceleration expansion of universe, crossing the…

宇宙学与河外天体物理 · 物理学 2015-06-04 Kh. Saaidi , A. Aghamohammadi