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Cosmological observations of the recent universe suggest that dark energy equation of state parameter $w$ is growing with time, departing from a cosmological constant for which $w=-1$. Standard quintessence models allow for a varying…

High Energy Physics - Theory · Physics 2025-07-11 David Andriot

Recent determinations of the equation of state of dark energy hint that this may well be of the phantom type, i.e., $w_{de} < -1$. If confirmed by future experiments, this would strongly point to the existence of fields that violate the…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Rafael C. Nunes , Diego Pavón

In this paper, we study an interacting holographic dark energy model in the framework of fractal cosmology. The features of fractal cosmology could pass ultraviolet divergencies and also make a better understanding of the universe in…

General Relativity and Quantum Cosmology · Physics 2018-10-16 Ehsan Sadri , Martiros Khurshudyan , Surajit Chattopadhyay

Dark energy (DE) models with many free parameters are often considered excessive, as constraining all parameters poses a significant challenge. While such models offer greater flexibility to probe the DE sector in more detail. With the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 Hanyu Cheng , Supriya Pan , Eleonora Di Valentino

The present work is an attempt to investigate whether the evolutionary history of the Universe from the offset of inflation can be described by assuming the cosmic fluid to be an ideal gas with a specific gas constant but a varying negative…

General Physics · Physics 2018-04-10 Subhajit Saha , Anindita Mondal , Christian Corda

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

We study a cosmological model in which phantom dark energy is coupled to dark matter by phenomenologically introducing a coupled term to the equations of motion of dark energy and dark matter. This term is parameterized by a dimensionless…

High Energy Physics - Theory · Physics 2009-11-10 Rong-Gen Cai , Anzhong Wang

The phenomenologically emergent dark energy (PEDE) model is a varying dark energy model with no extra degrees of freedom proposed by Li and Shafieloo\citep{Li_2019} to alleviate the Hubble tension. The statistical consistency of the model…

General Relativity and Quantum Cosmology · Physics 2023-08-09 Rosemin John , Sarath N. , Titus K. Mathew

In this work we discuss a general approach for the dark energy thermodynamics considering a varying equation of state (EoS) parameter of the type $\omega(a)=\omega_0+F(a)$ and taking into account the role of a non-zero chemical potential…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-12 H. H. B. Silva , R. Silva , R. S. Gonçalves , Zong-Hong Zhu , J. S. Alcaniz

It is extraordinary that a number of observations indicate that we live in a spatially flat, low matter density Universe, which is currently undergoing a period of accelerating expansion. The effort to explain this current state has focused…

Astrophysics · Physics 2010-02-18 R. R. Caldwell

We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an…

General Relativity and Quantum Cosmology · Physics 2017-07-07 Yoelsy Leyva , Mirko Sepúlveda

Dynamical dark energy (DE) phenomenon emerges as a geometrical effect accompanying the cosmological expansion of nonrelativistic fermionic matter. This occurs without the need for any fluid, like e.g. dynamical scalar field (quintessence,…

General Relativity and Quantum Cosmology · Physics 2013-03-14 E. I. Guendelman , A. B. Kaganovich

Dark matter drops out of kinetic equilibrium with standard model particles when the momentum-transfer rate equals the expansion rate. In a radiation-dominated universe, this occurs at essentially the same time as dark matter kinetically…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-12 Isaac Raj Waldstein , Adrienne L. Erickcek , Cosmin Ilie

Exploring the accelerated expansion of the universe, we investigate the generalized ghost dark energy (GGDE) model from the statefinder diagnosis analysis in a flat FRW universe. First we calculate the cosmological evolution and statefinder…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Mohammad Malekjani

We investigate the new agegraphic dark energy (NADE) model with power-law corrected entropy in the framework of Ho\v{r}ava-Lifshitz cosmology. For a non-flat universe containing the interacting power-law entropy-corrected NADE (PLECNADE)…

General Physics · Physics 2012-05-14 K. Karami , A. Sheykhi , Mubasher Jamil , R. Myrzakulov , S. Ghaffari , A. Abdolmaleki

We uncover the general mechanism producing the dark energy(DE). This is only based on well known quantum physics and cosmology. We show that the observed DE originates from the cosmological quantum vacuum of light particles which provides a…

Astrophysics · Physics 2023-04-05 Hector J. de Vega , Norma G. Sanchez

A so-called "entropy-corrected holographic dark energy" (ECHDE), was recently proposed to explain the dark energy-dominated universe with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology.…

General Physics · Physics 2014-11-20 Mubasher Jamil , Ahmad Sheykhi , M. Umar Farooq

Recently, the observed equation of state for dark energy appears to favor values below $-1$. The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant. In view of the adjustment on the…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Yu-Ping Teng , Wolung Lee , Kin-Wang Ng

We have developed an accelerating cosmological model for the present universe which is phantom for the period $ (0 \leq z \leq 1.99)$ and quintessence phase for $(1.99 \leq z \leq 2.0315)$. The universe is assumed to be filled with…

General Relativity and Quantum Cosmology · Physics 2021-08-02 G. K. Goswami , Anirudh Pradhan , A. Beesham

In this work, we have considered the recently proposed new Tsallis Agegraphic Dark Energy model (NTADE) (Mod. Phys. Lett. A 34, 1950086, 2019) within the framework of a flat Friedmann-Robertson-Walker(FRW) Universe by taking various values…

General Relativity and Quantum Cosmology · Physics 2021-05-18 Umesh Kumar Sharma , Shikha Srivastava