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相关论文: Spherical collapse model in agegraphic dark energy…

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In this work, we study the collapse dynamics of an inhomogeneous spherically symmetric star made of dark matter (DM) and dark energy (DE). The dark matter is taken in the form of a dust cloud while anisotropic fluid is chosen as the…

广义相对论与量子宇宙学 · 物理学 2014-11-17 Subenoy Chakraborty , Tanwi Bandyopadhyay

A simple speed-up cosmology model is proposed to account for the dark energy puzzle. We condense contributions from dark energy and curvature term into one effective parameter in order to reduce parameter degeneracies and to find any…

天体物理学 · 物理学 2007-10-10 Xin-He Meng , Meng Su , Zheng Wang

We present a new collapse condition to describe the formation of dark halos via nonspherical gravitational clustering. This new nonspherical collapse condition is obtained by the logical generalization of the spherical model to the…

天体物理学 · 物理学 2009-10-31 Tzihong Chiueh , Jounghun Lee

We investigate dark matter halo properties as a function of a time--varying dark energy equation of state. The dynamics of the collapse of the halo is governed by the form of the quintessence potential, the time evolution of its equation of…

天体物理学 · 物理学 2009-05-04 David F. Mota

Observations have confirmed the accelerated expansion of the universe. The accelerated expansion can be modelled by invoking a cosmological constant or a dynamical model of dark energy. A key difference between these models is that the…

宇宙学与河外天体物理 · 物理学 2018-06-13 Manvendra Pratap Rajvanshi , Jasjeet Singh Bagla

We use a high-resolution $N$-body simulation to study how the formation of cold dark matter (CDM) halos is affected by their environments, and how such environmental effects produce the age-dependence of halo clustering observed in recent…

天体物理学 · 物理学 2008-11-26 H. Y. Wang , H. J. Mo , Y. P. Jing

Observations favor cosmological models with a time-varying dark energy component. But how does dynamical dark energy (DDE) influence the growth of structure in an expanding Universe? We investigate this question using high-resolution…

宇宙学与河外天体物理 · 物理学 2025-07-08 Tomoaki Ishiyama , Francisco Prada , Anatoly A. Klypin

One of the non-canonical descriptions of scalar field dark energy is the tachyon. The present work is devoted to study the dynamics of dark matter overdensity in a conformally coupled tachyon field dark energy model. The model is tuned to…

宇宙学与河外天体物理 · 物理学 2020-09-02 Ankan Mukherjee

We argue that a few per cent of "Early Dark Energy" can be detected by the statistics of nonlinear structures. The presence of Dark Energy during linear structure formation is natural in models where the present tiny Dark-Energy density is…

天体物理学 · 物理学 2009-01-28 Matthias Bartelmann , Michael Doran , Christof Wetterich

Employing the spherical collapse (SC) formalism, we investigate the linear evolution of the matter over-density for energy-momentum-squared gravity (EMSG), which in practical phenomenological terms, one may imagine as an extension of the…

宇宙学与河外天体物理 · 物理学 2023-07-26 Bita Farsi , Ahmad Sheykhi , Mohsen Khodadi

We train a machine learning algorithm to learn cosmological structure formation from N-body simulations. The algorithm infers the relationship between the initial conditions and the final dark matter haloes, without the need to introduce…

宇宙学与河外天体物理 · 物理学 2018-07-02 Luisa Lucie-Smith , Hiranya V. Peiris , Andrew Pontzen , Michelle Lochner

We explore the effects of small scale structure on the formation and equilibrium of dark matter halos in a universe dominated by vacuum energy. We present the results of a suite of four N-body simulations, two with a LCDM initial power…

天体物理学 · 物理学 2011-02-11 Michael T. Busha , August E. Evrard , Fred C. Adams

The top-hat spherical collapse model (TSC) is one of the most fundamental analytical frameworks to describe the non-linear growth of cosmic structure. TSC has motivated, and been widely applied in, various researches even in the current era…

宇宙学与河外天体物理 · 物理学 2016-01-20 Daichi Suto , Tetsu Kitayama , Ken Osato , Shin Sasaki , Yasushi Suto

It is of fundamental importance to determine if and how hierarchical clustering is involved in large-scale structure formation of the universe. Hierarchical evolution is characterized by rules which specify how dark matter halos are formed…

天体物理学 · 物理学 2009-10-30 J. Pando , P. Lipa , M. Greiner , L. Z. Fang

The dark energy dominated warm dark matter (WDM) model is a promising alternative cosmological scenario. We explore large-scale structure formation in this paradigm. We do this in two different ways: with the halo model approach and with…

宇宙学与河外天体物理 · 物理学 2015-06-03 Aurel Schneider , Robert E. Smith , Andrea V. Maccio , Ben Moore

We revisit the non-sphericity of cluster-mass scale halos from cosmological N-body simulation on the basis of triaxial modelling. In order to understand the difference between the simulation results and the conventional ellipsoidal collapse…

宇宙学与河外天体物理 · 物理学 2016-10-12 Daichi Suto , Tetsu Kitayama , Takahiro Nishimichi , Shin Sasaki , Yasushi Suto

We construct $(m,n)$-type holographic dark energy models at a phenomenological level, which can be viewed as a generalization of agegraphic models with the conformal-like age as the holographic characteristic size. For some values of…

广义相对论与量子宇宙学 · 物理学 2013-09-19 Yi Ling , Wen-Jian Pan

Accurate knowledge of the non-linear dark-matter power spectrum is important for understanding the large-scale structure of the Universe, the statistics of dark-matter haloes and their evolution, and cosmological gravitational lensing. We…

宇宙学与河外天体物理 · 物理学 2015-05-18 Carlo Giocoli , Matthias Bartelmann , Ravi K. Sheth , Marcello Cacciato

Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit {\black or overpredict} the development of observed large-scale structures. Traditional approaches to…

宇宙学与河外天体物理 · 物理学 2010-10-28 C. Prescod-Weinstein , N. Afshordi

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…

广义相对论与量子宇宙学 · 物理学 2015-06-11 M. Malekjani , R. Zarei , M. Honari-Jafarpour