Ellipsoidal collapse and previrialization

Abstract

We study the non-linear evolution of a dust ellipsoid,embedded in a Friedmann flat background universe, in order to determine the evolution of the density of the ellipsoid as the perturbation to it related detaches from general expansion and begins to collapse. We show that while the growth rate of the density contrast of a mass element is enhanced by the shear in agreement with Hoffman (1986a), the angular momentum acquired by the ellipsoid has the right magnitude to counterbalance the effect of the shear. The result confirms the previrialization conjecture (Peebles & Groth 1976; Davis & Peebles 1977; Peebles 1990) by showing that initial asphericities and tidal interactions begin to slow down the collapse after the system has broken away from the general expansion.

Cited by in corpus (26)

• Small scale problems of the $\Lambda$CDM model: a short review
• Accelerated expansion from structure formation
• The Cusp/Core problem and the Secondary Infall Model
• Collapse Barriers and Halo Abundance: Testing the Excursion Set Ansatz
• Dark matter and structure formation a review
• Environmental dependence in the ellipsoidal collapse model
• Evaluating backreaction with the peak model of structure formation
• Effects of shear and rotation on the spherical collapse model for clustering dark energy
• A theoretical study of the mass temperature relation for clusters of galaxies
• A high precision semi-analytic mass function
• On the Average Comoving Number Density of Halos
• Some improvements to the spherical collapse model
• An Improved Semi-Analytical Spherical Collapse Model for Non-linear Density Evolution
• The Local Hubble Flow: Is it a Manifestation of Dark Energy?
• On the cosmological mass function theory
• A theoretical study of the luminosity temperature relation for clusters of galaxies
• On the effect of angular momentum on the prompt cusp formation via the gravitational collapse
• Phase Space dynamics of triaxial collapse: Joint density-velocity evolution
• Evolution of the cosmological mass function in a moving barrier model
• The mass and temperature functions in a moving barrier model
• On the dwarf galaxies rotation curves diversity problem
• Improvements in the M-T relation and mass function and the measured Omega_m through clusters evolution
• Evaluating backreaction with the ellipsoidal collapse model
• Barions and $\Lambda$CDM Model Problems
• Morphology of dark matter haloes beyond triaxiality
• Cosmological constraints from clustering properties of galaxy clusters