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Related papers: Holographic dark energy with time varying $c^2$ pa…

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In this paper, bulk viscosity is introduced in new holographic dark energy (HDE) to describe the effects of cosmic non-perfect fluid on the evolution of the universe in modified $f(R,T)$ gravity. Assuming $f(R,T)=R+\lambda T$, where $R$ is…

General Relativity and Quantum Cosmology · Physics 2018-04-17 C P Singh , Milan Srivastava

Under the commonly used spherical collapse model, we study how dark energy affects the growth of large scale structures of the Universe in the context of agegraphic dark energy models. The dynamics of the spherical collapse of dark matter…

General Relativity and Quantum Cosmology · Physics 2017-10-11 M. Rezaei , M. Malekjani

We explore an extension of the $\Lambda$CDM model in which the pressure $p$ of the dark energy (DE) fluid evolves with the expansion of the Universe, expressed as a function of the scale factor $a$. The corresponding energy density $\rho$…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-22 Hanyu Cheng , Eleonora Di Valentino , Luis A. Escamilla , Anjan A. Sen , Luca Visinelli

We study the nonlinear evolution of matter overdensities using the spherical collapse model in degenerate higher-order scalar-tensor (DHOST) theories beyond Horndeski, employing the effective field theory (EFT) of dark energy approach. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Toshiki Takadera , Takashi Hiramatsu , Tsutomu Kobayashi

Using the generalized Tsallis entropy, the Tsallis holographic dark energy(THDE) was proposed recently. In this paper we analyze the cosmological consequences of the THDE model with an interaction between dark energy and dark matter…

General Relativity and Quantum Cosmology · Physics 2022-02-01 Qihong Huang , He Huang , Jun Chen , Lu Zhang , Feiquan Tu

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

We propose a two parameter generalization for the dark energy equation of state (EOS) $w_X$ for thawing dark energy models which includes PNGB, CPL and Algebraic thawing models as limiting cases and confront our model with the latest…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-09 Debabrata Adak , Debasish Majumdar , Supratik Pal

In this work we consider a general function for the $c^{2}$ term that appears in the conventional expression for the holographic dark energy in a FLRW curved spacetime. The cut-off prospective is inspired in the apparent horizon length. By…

General Relativity and Quantum Cosmology · Physics 2018-12-07 Miguel Cruz , Samuel Lepe

In the present work, we study the R$\acute{e}$nyi holographic dark energy model (RHDE) in a flat FRW Universe where the infrared cut-off is taken care by the Hubble horizon and also by taking three different parametrizations of the…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Umesh Kumar Sharma , Vipin Chandra Dubey

Considering the power-law corrections to the black hole entropy, which appear in dealing with the entanglement of quantum fields inside and outside the horizon, the holographic energy density is modified accordingly. In this paper we study…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-08 A. Sheykhi , K. Karami , Mubasher Jamil , E. Kazemi , M. Haddad

The holographic dark energy model is proposed by Li as an attempt for probing the nature of dark energy within the framework of quantum gravity. The main characteristic of holographic dark energy is governed by a numerical parameter $c$ in…

Astrophysics · Physics 2008-11-26 Xin Zhang , Feng-Quan Wu

The new agegraphic Dark Energy (NADE) model (based on generalized uncertainty principle) interacting with Dark Matter (DM) is considered in this study via power-law form of the scale factor $a(t)$. The equation of state (EoS) parameter…

General Physics · Physics 2013-11-14 Antonio Pasqua , Surajit Chattopadhyay , Iuliia Khomenko

Knowing the late time evolution of the Universe and finding out the causes for this evolution are the important challenges of modern cosmology. In this work, we adopt a model-independent cosmographic approach and approximate the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 Salvatore Capozziello , Ruchika , Anjan A Sen

In this paper, we consider a recently proposed model of Dark Energy (DE) which contains three terms (one proportional to the squared Hubble parameter, one to the first derivative with respect to the cosmic time of the Hubble parameter and…

General Physics · Physics 2013-09-13 Antonio Pasqua , Surajit Chattopadhyay , Ratbay Myrzakulov

The some models of holographic dark energy for Randall-Sandrum brane are considered. For first class of dark energy models we take energy density in form $\sim L^{2\gamma-4}$ where $L$ is size of events horizon in Universe and $\gamma$ is…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Artyom V. Astashenok , Alexander S. Tepliakov

In this work, we investigate two Dark Energy (DE) models characterized by higher-order derivatives of the Hubble parameter $H$, which generalize previously proposed DE scenarios. Assuming a power-law form of the scale factor $a(t)$ given by…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Antonio Pasqua

The behavior of perturbation in scalar field dark energy and its consequent effect on the cold dark matter (CDM) power spectrum is well understood to be governed by the equation of state (EOS) parameter and the effective speed of sound…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-26 Rizwan Ul Haq Ansari , Sanil Unnikrishnan

In a recent work [Phys. Rev. D 98, 043521 (2018)], we have investigated a dark matter (DM)-photon coupling model in which the DM decays into photons in the presence of dark energy (DE) with the constant equation of state (EoS) parameter.…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-30 Santosh Kumar Yadav

A new dark energy model in anisotropic Bianchi type-III space-time with variable equation of state (EoS) parameter has been investigated in the present paper. To get the deterministic model, we consider that the expansion $\theta$ in the…

General Physics · Physics 2014-07-15 Anirudh Pradhan , Hassan Amirhashchi

So far, there have been no theories or observational data that deny the presence of interaction between dark energy and dark matter. We extend naturally the holographic dark energy (HDE) model, proposed by Granda and Oliveros, in which the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Fei Yu , Jingfei Zhang , Jianbo Lu , Wei Wang , Yuanxing Gui