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In this work we investigate the spherical collapse model in flat FRW universe containing dark energy component. We consider the Holographic Dark Energy (HDE) model as a dynamical dark energy scenario with slowly time varying EoS parameter…

General Relativity and Quantum Cosmology · Physics 2014-05-27 Tayebe Naderi , Mohammad Malekjani

We study the structure formation by investigating the spherical collapse model in the context of new agegraphic dark energy model in flat FRW cosmology. We compute the perturbational quantities $g(a)$, $\delta_{c}(z_{c})$, $\lambda(z_{c})$,…

General Relativity and Quantum Cosmology · Physics 2017-07-05 M. R. Setare , F. Felegary , F. Darabi

We study the spherical collapse model for several dark energy scenarios using the fully nonlinear differential equation for the evolution of the density contrast within homogeneous spherical overdensities derived from Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Pace , J. -C. Waizmann , M. Bartelmann

We study the imprints on the formation of cosmic structures of a particular class of dark energy parameterizations dubbed PADE parameterization. Here we investigate how dark energy can affect the growth of large scale structures of the…

General Relativity and Quantum Cosmology · Physics 2019-05-07 Mehdi Rezaei

We use the non-linear spherical model in cold dark matter (CDM) cosmologies with dark energy to investigate the effects of dark energy on the growth of structure and the formation of virialised structures. We consider dark energy models…

Astrophysics · Physics 2010-12-09 Cathy Horellou , Joel Berge

We investigate the clustering effect of dark energy (DE) in the formation of galaxy clusters using the spherical collapse model. Assuming a fully clustered DE component, the spherical overdense region is treated as an isolated system which…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-02 Chia-Chun Chang , Wolung Lee , Kin-Wang Ng

We investigate the virialization of cosmic structures in the framework of flat FLRW cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 S. Basilakos , M. Plionis , J. Sola

There is now strong evidence that the current energy density of the Universe is dominated by dark energy with an equation of state w<-1/3, which is causing accelerated expansion. The build-up of structure within such Universes is subject to…

Astrophysics · Physics 2008-11-26 Will J. Percival

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

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

While in the standard cosmological model the accelerated expansion of the Universe is explained by invoking the presence of the cosmological constant term, it is still unclear the true origin of this stunning observational fact. It is…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Mohammad Malekjani , Tayebe Naderi , Francesco Pace

Inspired by the multiverse scenario, we study a heterotic dark energy model in which there are two parts, the first being the cosmological constant and the second being the holographic dark energy, thus this model is named the $\Lambda$HDE…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 Yazhou Hu , Miao Li , Nan Li , Zhenhui Zhang

We study non-linear structure formation in high-resolution simulations of Early Dark Energy (EDE) cosmologies and compare their evolution with the standard LCDM model. Extensions of the spherical top-hat collapse model predict that the…

Astrophysics · Physics 2011-02-11 Margherita Grossi , Volker Springel

Holographic dark energy theories present a fascinating interface to probe late-time cosmology, as guided by contemporary ideas about quantum gravity. In this work, we present a new holographic dark energy scenario designated Fractional…

General Relativity and Quantum Cosmology · Physics 2024-12-03 Oem Trivedi , Ayush Bidlan , Paulo Moniz

R\'enyi Holographic Dark Energy (RHDE) Models has been studied in different dimensions considering a flat FRW metric, subsequently exploring the nature of evolution of different cosmological parameters. It is seen that the number of…

General Relativity and Quantum Cosmology · Physics 2022-02-22 A. Saha , A. Chanda , S. Dey , B. C. Paul , S. Ghose

We consider the holographic dark energy model in which the model parameter $c^2$ evolves slowly with time. First we calculate the evolution of EoS parameter as well as the deceleration parameter in this generalized version of holographic…

General Relativity and Quantum Cosmology · Physics 2015-06-11 M. Malekjani , R. Zarei , M. Honari-Jafarpour

We review the paradigm of holographic dark energy (HDE), which arises from a theoretical attempt of applying the holographic principle (HP) to the dark energy (DE) problem. Making use of the HP and the dimensional analysis, we derive the…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-24 Shuang Wang , Yi Wang , Miao Li

In a previous paper, we proposed a heterotic dark energy model, called $\Lambda$HDE, in which dark energy is composed of two components: cosmological constant (CC) and holographic dark energy (HDE). The aim of this work is to give a more…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-17 Shuang Wang , Sixiang Wen , Lanjun Zhou , Miao Li

We investigate a spherical overdensity model for the non-clustering dark energy (DE) with the constant equation of state, w in a flat universe. In this case, the exact solution for the evolution of the scale factor is obtained for general…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-27 Seokcheon Lee , Kin-Wang Ng

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
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