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相关论文: Evolution of Spherical Overdensity in Thawing Dark…

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We investigate in this paper the cosmological evolution of a dark energy model with two scalar fields where one of the scalar has canonical kinetic energy and another scalar has negative kinetic energy term. For such a system with…

天体物理学 · 物理学 2007-05-23 Zong-Kuan Guo , Yun-Song Piao , Xinmin Zhang , Yuan-Zhong Zhang

We extend the analysis of Pace et al., JCAP, 2019, 060, by considering the virialization process in the extended spherical collapse model for clustering dark-energy models, i.e., accounting for dark-energy fluctuations. Differently from the…

宇宙学与河外天体物理 · 物理学 2022-04-07 Francesco Pace , Carlo Schimd

We perform a study both statistical and theoretical for cosmological models of matter creation and their ability to describe effective phantom models of dark energy. Such models are beyond the $\Lambda$CDM model since the resulting cosmic…

广义相对论与量子宇宙学 · 物理学 2020-04-23 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe , Shin'ichi Nojiri , Sergei D. Odintsov

Cool cluster cores are in global thermal equilibrium but are locally thermally unstable. We study a nonlinear phenomenological model for the evolution of density perturbations in the ICM due to local thermal instability and gravity. We have…

星系天体物理 · 物理学 2015-06-22 Ashmeet Singh , Prateek Sharma

We investigate the influence of dark energy on structure formation, within five different cosmological models, namely a concordance $\Lambda$CDM model, two models with dynamical dark energy, viewed as a quintessence scalar field (using a RP…

宇宙学与河外天体物理 · 物理学 2015-05-19 Cristiano De Boni , Klaus Dolag , Stefano Ettori , Lauro Moscardini , Valeria Pettorino , Carlo Baccigalupi

We investigate the evolution of non-linear density perturbations by taking into account the effects of deviations from spherical symmetry of a system. Starting from the standard spherical top hat model in which these effects are ignored, we…

天体物理学 · 物理学 2009-10-31 S. Engineer , Nissim Kanekar , T. Padmanabhan

We study structure formation using relativistic cosmological linear perturbation theory in the presence of intrinsic and relative (with respect to matter) non-adiabatic dark energy perturbations. For different dark energy models we assess…

宇宙学与河外天体物理 · 物理学 2017-10-04 Hermano Velten , Raquel Fazolo

Applying the parametrization of dark energy density, we can construct directly independent-model potentials. In Born-Infeld type phantom dark energy model, we consider four special parametrization equation of state parameter. The evolutive…

高能物理 - 理论 · 物理学 2009-10-29 Z. G. Huang , H. Q. Lu , W. Fang

We examine a dark energy model where a scalar unparticle degree of freedom plays the role of quintessence. In particular, we study a model where the unparticle degree of freedom has a standard kinetic term and a simple mass potential, the…

宇宙学与河外天体物理 · 物理学 2009-11-06 De-Chang Dai , Sourish Dutta , Dejan Stojkovic

We study the evolution of spatial curvature for thawing class of dark energy models. We examine the evolution of the equation of state parameter, $w_\phi$, as a function of the scale factor $a$, for the case in which the scalar field $\phi$…

宇宙学与河外天体物理 · 物理学 2011-01-27 Sergio del Campo , Victor H. Cardenas , Ramon Herrera

It is well known that a canonical scalar field is able to describe either dark matter or dark energy but not both. We demonstrate that a non-canonical scalar field can describe both dark matter and dark energy within a unified setting. We…

宇宙学与河外天体物理 · 物理学 2016-05-12 Varun Sahni , Anjan A Sen

Within the framework of Unimodular Gravity, we consider non-gravitational interactions between dark matter and dark energy. Particularly, we describe such interactions in the dark sector by considering diffusion models that couple the cold…

宇宙学与河外天体物理 · 物理学 2021-03-31 Francisco X. Linares Cedeño , Ulises Nucamendi

We investigate a spherical collapse model with and without the spatial curvature. We obtain the exact solutions of dynamical quantities such as the ratio of the scale factor to its value at the turnaround epoch and the ratio of the…

宇宙学与河外天体物理 · 物理学 2010-03-29 Seokcheon Lee

We consider different classes of scalar field models including quintessence, and tachyon scalar fields with a variety of generic potential belonging to thawing type. Assuming the scalar field is initially frozen at $w=-1$, we evolve the…

宇宙学与河外天体物理 · 物理学 2015-05-13 S. Sen , A. A. Sen , M. Sami

In existing literatures about the top-hat spherical collapse model of galaxy clusters formation in cosmology containing dark energies, dark energies are usually assumed not to cluster on this scale. But all these literatures ignored the…

天体物理学 · 物理学 2016-08-30 Ding-fang Zeng , Yi-hong Gao

The cosmological evolution in Nonlinear Born-Infeld(hereafter NLBI) scalar field theory with negative potentials was investigated. The cosmological solutions in some important evolutive epoches were obtained. The different evolutional…

高能物理 - 理论 · 物理学 2008-11-26 Wei Fang , H. Q. Lu , Z. G. Huang

Considering an arbitrary, varying equation of the state parameter, the thermodynamic properties of the dark energy fluid in a semiclassical loop quantum cosmology scenario, which we consider the inverse volume modification, is studied. The…

广义相对论与量子宇宙学 · 物理学 2011-03-22 Kui Xiao , Jian-Yang Zhu

We study a class of Unified Dark Matter (UDM) models based on generalized K-essence, where a single scalar field with non-canonical kinetic terms accounts for dark radiation, dark matter, and dark energy. Starting from the purely kinetic…

宇宙学与河外天体物理 · 物理学 2026-02-26 Eladio Moreno , Josue De-Santiago

We study, for the first time, how shear and angular momentum modify typical parameters of the spherical collapse model, in dark energy dominated universes. In particular, we study the linear density threshold for collapse…

宇宙学与河外天体物理 · 物理学 2014-02-04 A. Del Popolo , F. Pace , J. A. S. Lima

We provide a generic but physically clear discussion of the clustering properties of dark energy models. We explicitly show that in quintessence-type models the dark energy fluctuations, on scales smaller than the Hubble radius, are of the…

天体物理学 · 物理学 2008-11-26 P. P. Avelino , L. M. G. Beca , C. J. A. P. Martins