Spherical collapse model and cluster formation beyond the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Λ</mml:mi></mml:math>cosmology: Indications for a clustered dark energy?

Basilakos, Spyros; Sánchez, Juan C. Bueno; Perivolaropoulos, Leandros

doi:10.1103/physrevd.80.043530

Cited by 56 publications

(48 citation statements)

References 99 publications

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“…For completeness, we also examine the case where the dark energy field is clustered (see, e.g., Refs. [37,38]). From the previous results of δ c , we found that the homogeneous case shows slightly higher value than the inhomogeneous one in both freezing and thawing models.…”

Section: Fig 3: Left Panelsmentioning

confidence: 99%

Constraining thawing and freezing models with cluster number counts

Devi¹,

González²,

Alcaniz³

2014

J. Cosmol. Astropart. Phys.

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Measurements of the cluster abundance as a function of mass and redshift provide an important cosmological test that probe not only the expansion rate but also the growth of perturbations. In this paper we adopt a scalar field scenario which admits both thawing and freezing solutions from an appropriate choice of the model parameters and derived all relevant expressions to calculate the mass function and the cluster number density. We discuss the ability of cluster observations to distinguish between these scalar field behaviors and the standard ΛCDM scenario by considering the eROSITA and SPT cluster surveys.PACS numbers: 98.80.Es, 95.36.+x

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Section: Fig 3: Left Panelsmentioning

confidence: 99%

Constraining thawing and freezing models with cluster number counts

Devi¹,

González²,

Alcaniz³

2014

J. Cosmol. Astropart. Phys.

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“…It has also been shown that predictions of the spherical collapse model strongly depend on the scalar field potential adopted in a minimally coupled scalar field scenario (Mota & van de Bruck 2004). When DE clusters, Basilakos et al (2009Basilakos et al ( , 2010 showed that more concentrated structures can be formed with respect to a homogeneous DE model. Bartelmann et al (2006) and Pace et al (2010) extended the spherical collapse model in the presence of early DE models and showed that the growth of structures is slowed down with respect to the ΛCDM model.…”

Section: Introductionmentioning

confidence: 99%

Evolution of spherical overdensities in holographic dark energy models

Naderi¹,

Malekjani²,

Pace³

2015

Monthly Notices of the Royal Astronomical Society

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In this work we investigate the spherical collapse model in flat FRW dark energy universes. We consider the Holographic Dark Energy (HDE) model as a dynamical dark energy scenario with a slowly time-varying equation-of-state (EoS) parameter w de in order to evaluate the effects of the dark energy component on structure formation in the universe. We first calculate the evolution of density perturbations in the linear regime for both phantom and quintessence behavior of the HDE model and compare the results with standard Einstein-de Sitter (EdS) and ΛCDM models. We then calculate the evolution of two characterizing parameters in the spherical collapse model, i.e., the linear density threshold δ c and the virial overdensity parameter ∆ vir . We show that in HDE cosmologies the growth factor g(a) and the linear overdensity parameter δ c fall behind the values for a ΛCDM universe while the virial overdensity ∆ vir is larger in HDE models than in the ΛCDM model. We also show that the ratio between the radius of the spherical perturbations at the virialization and turn-around time is smaller in HDE cosmologies than that predicted in a ΛCDM universe. Hence the growth of structures starts earlier in HDE models than in ΛCDM cosmologies and more concentrated objects can form in this case. It has been shown that the non-vanishing surface pressure leads to smaller virial radius and larger virial overdensity ∆ vir . We compare the predicted number of halos in HDE cosmologies and find out that in general this value is smaller than for ΛCDM models at higher redshifts and we compare different mass function prescriptions. Finally, we compare the results of the HDE models with observations.

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“…Bernardeau 1994;Bardeen et al 1986;Ohta et al 2003Ohta et al , 2004Basilakos et al 2009;Pace et al 2010;Basilakos et al 2010) assuming that dark energy perturbations are negligible, while other studies took into account also the effects of perturbations for the dark energy fluid (see Mota & van de Bruck 2004;Nunes & Mota 2006;Abramo et al 2007Abramo et al , 2008Creminelli et al 2010;Basse et al 2011;Batista & Pace 2013). More recently, the spherical collapse model was extended to investigate coupled (Pettorino & Baccigalupi 2008;Wintergerst & Pettorino 2010;Tarrant et al 2012) and extended dark energy (scalar-tensor) models (Pettorino & Baccigalupi 2008;Pace et al 2014).…”

Section: Extended Spherical Collapse Model (Escm)mentioning

confidence: 99%

Effects of shear and rotation on the spherical collapse model for clustering dark energy

Pace¹,

Batista²,

Popolo³

2014

Monthly Notices of the Royal Astronomical Society

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In the framework of the spherical collapse model we study the influence of shear and rotation terms for dark matter fluid in clustering dark energy models. We evaluate, for different equations of state, the effects of these terms on the linear overdensity threshold parameter, δ c , and on the virial overdensity, ∆ V . The evaluation of their effects on δ c allows us to infer the modifications occurring on the mass function. Due to ambiguities in the definition of the halo mass in the case of clustering dark energy, we consider two different situations: the first is the classical one where the mass is of the dark matter halo only, while the second one is given by the sum of the mass of dark matter and dark energy. As previously found, the spherical collapse model becomes mass dependant and the two additional terms oppose to the collapse of the perturbations, especially on galactic scales, with respect to the spherical non-rotating model, while on clusters scales the effects of shear and rotation become negligible. The values for δ c and ∆ V are higher than the standard spherical model. Regarding the effects of the additional non-linear terms on the mass function, we evaluate the number density of halos. As expected, major differences appear at high masses and redshifts. In particular, quintessence (phantom) models predict more (less) objects with respect to the ΛCDM model and the mass correction due to the contribution of the dark energy component has negligible effects on the overall number of structures.

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Spherical collapse model and cluster formation beyond theΛcosmology: Indications for a clustered dark energy?

Cited by 56 publications

References 99 publications

Constraining thawing and freezing models with cluster number counts

Constraining thawing and freezing models with cluster number counts

Evolution of spherical overdensities in holographic dark energy models

Effects of shear and rotation on the spherical collapse model for clustering dark energy

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