Spherical collapse of dark matter haloes in tidal gravitational fields

Abstract

We study the spherical collapse model in the presence of external gravitational tidal shear fields for different dark energy scenarios and investigate the impact on the mass function and cluster number counts. While previous studies of the influence of shear and rotation on ${\delta }_{\mathrm{c}}$ have been performed with heuristically motivated models, we try to avoid this model dependence and sample the external tidal shear values directly from the statistics of the underlying linearly evolved density field based on first order Lagrangian perturbation theory. Within this self-consistent approach, in the sense that we restrict our treatment to scales where linear theory is still applicable, only fluctuations larger than the scale of the considered objects are included into the sampling process which naturally introduces a mass dependence of ${\delta }_{\mathrm{c}}$. We find that shear effects are predominant for smaller objects and at lower redshifts, i. e. the effect on ${\delta }_{\mathrm{c}}$ is at or below the percent level for the $\Lambda$CDM model. For dark energy models we also find small but noticeable differences, similar to $\Lambda$CDM. The virial overdensity ${\Delta }_{\mathrm{V}}$ is nearly unaffected by the external shear. The now mass dependent ${\delta }_c$ is used to evaluate the mass function for different dark energy scenarios and afterwards to predict cluster number counts, which indicate that ignoring the shear contribution can lead to biases of the order of $1\sigma$ in the estimation of cosmological parameters like ${\Omega }_{\mathrm{m}}$, ${\sigma }_8$ or $w$.

arXiv comment12 pages, 10 figures, submitted to MNRAS

References in corpus (39)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Dynamics of dark energy
• Large scale bias and the peak background split
• Exploring the Expansion History of the Universe
• Accelerating Universes with Scaling Dark Matter
• The 2dF Galaxy Redshift Survey: Power-spectrum analysis of the final dataset and cosmological implications
• Ellipsoidal collapse and an improved model for the number and spatial distribution of dark matter haloes
• Mass function of dark matter halos
• Quintessence arising from exponential potentials
• On the spherical collapse model in dark energy cosmologies
• On Formation and Evolution of Disk Galaxies: Cosmological Initial Conditions and the Gravitational Collapse
• A model independent approach to the dark energy equation of state
• Skewness and Kurtosis in Large-Scale Cosmic Fields
• Review: galactic angular momenta and angular momentum correlations in the cosmological large-scale structure
• Structure formation in the presence of dark energy perturbations
• Cosmological parameter constraints from SDSS luminous red galaxies: a new treatment of large-scale clustering
• Quintessence models in Supergravity
• Spherical collapse model in dark energy cosmologies
• Spherical collapse model with shear and angular momentum in dark energy cosmologies
• An analytic approach to number counts of weak-lensing peak detections
• Effects of shear and rotation on the spherical collapse model for clustering dark energy
• A comparison of structure formation in minimally and non-minimally coupled quintessence models
• Extended Spherical Collapse and the Accelerating Universe
• Structure formation in cosmologies with oscillating dark energy
• Cosmological Density Distribution Function from the Ellipsoidal Collapse Model in Real Space
• Evolution of Cosmological Density Distribution Function from the Local Collapse Model
• The correlation of peaks in the microwave background
• Spherical collapse in modified gravity with the Birkhoff-theorem
• Imprints of primordial non-Gaussianity on the number counts of cosmic shear peaks
• The signature of dark energy perturbations in galaxy cluster surveys
• Galactic angular momenta and angular momentum couplings in the large-scale structure
• Triaxial collapse and virialisation of dark-matter haloes
• Constraining Dark Energy by Combining Cluster Counts and Shear-Shear Correlations in a Weak Lensing Survey
• The hybrid SZ power spectrum: Combining cluster counts and SZ fluctuations to probe gas physics
• Extreme value statistics of weak lensing shear peak counts
• Statistics of gravitational potential perturbations: A novel approach to deriving the X-ray temperature function
• Phenomenological aspects of dark energy dominated cosmologies

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• Tidal virialization of dark matter haloes with clustering dark energy
• Effects of dynamical friction on perturbations for evolving dark energy