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In this paper we show that a \emph{one-to-one} correspondence exists between any dark energy model and an equivalent (from a cosmological point of view, in the absence of perturbations) quartessence model in which dark matter and dark…

Astrophysics · Physics 2009-11-11 L. M. G. Beca , P. P. Avelino

In this paper, we derive some new invariant solutions of dark energy models in cylindrically symmetric space-time. To quantify the deviation of pressure from isotropy, we introduce three different time dependent skewness parameters along…

General Relativity and Quantum Cosmology · Physics 2014-09-10 Anil Kumar Yadav , Ahmad T Ali

In this paper, we interpret the dark energy as an effect caused by small scale inhomogeneities of the universe with the use of the spatial averaged approach of Buchert. The model considered here adopts the Chevallier-Polarski-Linder(CPL)…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Yan-Hong Yao , Xin-He Meng

In this paper the coupling between dark energy and the other components of the cosmological fluid has been studied. Firstly, it will be shown that the application of general cosmological equations, deduced by the authors in a previous work,…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-02 Alberto C. Balfagon , Raul Ramirez-Satorras , Angel R. Martinez

We demonstrate that the thermodynamics of a perfect fluid describing baryonic matter can, in certain limits, lead to an equation of state similar to that of dark energy. We keep the cosmic fluid equation of state quite general by just…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Georgios Lukes-Gerakopoulos , Giovanni Acquaviva , Charalampos Markakis

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-17 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Olga Mena , David F. Mota , Subenoy Chakraborty

We consider a Friedmann-Robertson-Walker cosmological model with some exotic perfect fluid with spin known as the Weyssenhoff fluid. The possibility that the dark energy may be described in part by the Weyssenhoff fluid is discussed. The…

Astrophysics · Physics 2008-07-22 Marek Szydlowski , Adam Krawiec

In this article, we review a series of recent theoretical results regarding a conventional approach to the dark energy (DE) concept. This approach is distinguished among others for its simplicity and its physical relevance. By compromising…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 Kostas Kleidis , Nikolaos K. Spyrou

This paper introduces the class of omnipotent dark energy (DE) models characterized by nonmonotonic energy densities that are capable of attaining negative values with corresponding equation of state parameters featuring phantom divide line…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-25 Shahnawaz A. Adil , Ozgur Akarsu , Eleonora Di Valentino , Rafael C. Nunes , Emre Ozulker , Anjan A. Sen , Enrico Specogna

Recent DESI baryon acoustic oscillation data reveal deviations from $\Lambda$CDM cosmology, conventionally attributed to dynamical dark energy (DE). We demonstrate that these deviations are equally, if not better, explained by interactions…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-13 Tian-Nuo Li , William Giarè , Guo-Hong Du , Yun-He Li , Eleonora Di Valentino , Jing-Fei Zhang , Xin Zhang

Since the discovery of the accelerated expansion of the universe, it was necessary to introduce a new component of matter distribution called dark energy. The standard cosmological model considers isotropy of the pressure and assumes an…

General Relativity and Quantum Cosmology · Physics 2012-10-25 R. Chan , M. F. A. da Silva , J. F. Villas da Rocha

The present work is a second in the series of investigation of the background dynamics in brane cosmology when dark energy is coupled to dark matter by a suitable interaction. Here, dark matter is chosen in the form of perfect fluid with…

General Physics · Physics 2019-06-21 Sujay Kr. Biswas , Subenoy Chakraborty

We investigate the impacts of dark energy on constraining massive (active/sterile) neutrinos in interacting dark energy (IDE) models by using the current observations. We employ two typical IDE models, the interacting $w$ cold dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-14 Lu Feng , Dong-Ze He , Hai-Li Li , Jing-Fei Zhang , Xin Zhang

Motivated by the current status of the cosmological observations and significant tensions in the estimated values of some key parameters assuming the standard $\Lambda$CDM model, we propose a simple but radical phenomenological emergent…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Xiaolei Li , Arman Shafieloo

We study the integrated Sachs-Wolfe (ISW) effect using a model-independent parameterization of the dark energy equation of state. Cosmic variance severely restricts the class of models distinguishable from Lambda-CDM. In particular if the…

Astrophysics · Physics 2009-11-07 P. S. Corasaniti , B. A. Bassett , C. Ungarelli , E. J. Copeland

We revise the conditions for the physical viability of a cosmological model in which dark matter has bulk viscosity and also interacts with dark energy. We have also included radiation and baryonic matter components; all matter components…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Arturo Avelino , Yoelsy Leyva , L. Arturo Urena-Lopez

In this paper, we study damped oscillating form of dark energy for explaining dynamics of universe. First of all, we consider universe is filled with an ideal fluid which has damped oscillating dark energy in terms of this case we calculate…

General Relativity and Quantum Cosmology · Physics 2015-08-13 Nilay Bostan , Ekrem Aydiner

The evolution of dark energy density is a crucial quantity in understanding the nature of dark energy. Often, the quantity is described by the so-called equation of state, that is the ratio of dark energy pressure to its density. In this…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-14 Ahmad Mehrabi , Maryam Vazirnia

We propose that the Hubble tension arises due to an unaccounted additional component, that behaves as \emph{matter with pressure}. We demonstrate that this fluid remains subdominant compared to both dust and radiation throughout nearly the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 Youri Carloni , Orlando Luongo , Marco Muccino

We investigate models of interacting dark matter and dark energy for the universe in a spatially flat Friedmann-Robertson-Walker (FRW) space-time. We find the "source equation" for the total energy density and determine the energy density…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Luis P. Chimento
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