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In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This…

宇宙学与河外天体物理 · 物理学 2012-10-16 P. P. Avelino , H. M. R. da Silva

Recently, the vacuum energy of the QCD ghost in a time-dependent background is proposed as a kind of dark energy candidate to explain the acceleration of the Universe. In this model, the energy density of the dark energy is proportional to…

高能物理 - 理论 · 物理学 2012-10-03 Chao-Jun Feng , Xin-Zhou Li , Xian-Yong Shen

Dark energy (DE) plays an important role in the expansion history of our universe. But we only got limited knowledge about its nature and properties after decades of study.In most numerical researches, DE is usually considered as a…

宇宙学与河外天体物理 · 物理学 2021-08-02 Ke Wang , Lu Chen

We study the cosmological evolutions of the equation of state for dark energy $w_{\mathrm{DE}}$ in the exponential and logarithmic as well as their combination $f(T)$ theories. We show that the crossing of the phantom divide line of…

宇宙学与河外天体物理 · 物理学 2015-03-17 Kazuharu Bamba , Chao-Qiang Geng , Chung-Chi Lee , Ling-Wei Luo

Following the idea of the induced matter theory, for a non-vacuum five-dimensional version of general relativity, we propose a model in which the induced terms emerging from the extra dimension in our four-dimensional space-time, supposed…

广义相对论与量子宇宙学 · 物理学 2018-07-27 Amir F. Bahrehbakhsh

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

A pressureless dark matter component fits well with several cosmological observations. However, there are indications that cold dark matter may encounter challenges in explaining observations at small scales, particularly at galactic…

宇宙学与河外天体物理 · 物理学 2025-04-17 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Olga Mena , David F. Mota , Subenoy Chakraborty

We present a complete analysis of the observational constraints and cosmological implications of our Bound Dark Energy (BDE) model aimed to explain the late-time cosmic acceleration of the universe. BDE is derived from particle physics and…

宇宙学与河外天体物理 · 物理学 2019-05-15 Erick Almaraz , Axel de la Macorra

In this dissertation, the nature of Dark Energy (DE) is examined from both theoretical and phenomenological perspectives. The possibility of DE being a dynamic quantity in quantum field theory (QFT) in curved spacetime is studied. The…

广义相对论与量子宇宙学 · 物理学 2023-11-14 Cristian Moreno-Pulido

We investigate, in a unified and general way, the thermodynamic properties of dark energy with an arbitrary, varying equation-of-state parameter w(a). We find that all quantities are well defined and regular for every w(a), including at the…

宇宙学与河外天体物理 · 物理学 2009-08-05 Emmanuel N. Saridakis , Pedro F. Gonzalez-Diaz , Carmen L. Siguenza

We explore a spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) universe which is filled with agegraphic dark energy (ADE) with mutual interaction with pressureless dark matter in the background of Brans-Dicke (BD) theory.…

广义相对论与量子宇宙学 · 物理学 2020-01-08 M. Abdollahi Zadeh , A. Sheykhi

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

天体物理学 · 物理学 2009-06-23 Nemanja Kaloper

It is well known that, in the context of general relativity, an unknown kind of matter that must violate the strong energy condition is required to explain the current accelerated phase of expansion of the Universe. This unknown component…

宇宙学与河外天体物理 · 物理学 2019-05-22 Ronaldo C. Duarte , Edésio M. Barboza , Everton M. C. Abreu , Jorge Ananias Neto

Since the discovery of the accelerated expansion of the Universe, the constraints on the equation of state $w_\text{DE}$ of dark energy, the stress-energy component responsible for the acceleration, have tightened significantly. These…

宇宙学与河外天体物理 · 物理学 2017-10-09 Fabian Schmidt

The thermodynamic properties of dark energy fluids described by an equation of state parameter $\omega=p/\rho$ are rediscussed in the context of FRW type geometries. Contrarily to previous claims, it is argued here that the phantom regime…

广义相对论与量子宇宙学 · 物理学 2014-11-18 S. H. Pereira , J. A. S. Lima

In the standard cosmological framework of the 0th-order FLRW metric and the use of perfect fluids in the stress-energy tensor, dark energy with an equation-of-state parameter $w < -1$ (known as phantom dark energy) implies negative kinetic…

广义相对论与量子宇宙学 · 物理学 2015-10-07 Kevin J. Ludwick

We examine cyclic phantom models for the universe, in which the universe is dominated sequentially by radiation, matter, and a phantom dark energy field, followed by a standard inflationary phase. Since this cycle repeats endlessly, the…

宇宙学与河外天体物理 · 物理学 2013-05-30 Hui-Yiing Chang , Robert J. Scherrer

In this paper, we point out thermodynamical description of ghost dark energy and its generalization to the early universe. Thereinafter, we find expressions for the entropy changes of these dark energy candidates. In addition, considering…

广义相对论与量子宇宙学 · 物理学 2015-05-06 M. Honarvaryan , A. Sheykhi , H. Moradpour

In this article, we investigate the existence of accelerating scaling solutions in coupled phantom cosmology without assuming any specific potential for the phantom scalar field. The coupling between phantom dark energy and dark matter is…

广义相对论与量子宇宙学 · 物理学 2026-02-11 Sudip Halder , Supriya Pan , Paulo M. Sá , Tapan Saha

We investigate the dynamical properties of dark energy through a detailed analysis of its equation of state parameter $w(z)$ as a function of redshift. We derive a general expression for $w(z)$ from the Friedmann-Lema\^itre-Robertson-Walker…

宇宙学与河外天体物理 · 物理学 2025-05-29 J. W. Moffat , E. J. Thompson