Self-Consistent Theory of Halo Mergers - II: CDM Power Spectra

Abstract

We place additional constraints on the three parameters of the dark matter halo merger rate function recently proposed by Parkinson, Cole & Helly by utilizing Smoluchowski's coagulation equation, which must be obeyed by any binary merging process which conserves mass. We find that the constraints from Smoluchowski's equation are degenerate, limiting to a thin plane in the three dimensional parameter space. This constraint is consistent with those obtained from fitting to N-body measures of progenitor mass functions, and provides a better match to the evolution of the overall dark matter halo mass function, particularly for the most massive halos. We demonstrate that the proposed merger rate function does not permit an exact solution of Smoluchowski's equation and, therefore, the choice of parameters must reflect a compromise between fitting various parts of the mass function. The techniques described herein are applicable to more general merger rate functions, which may permit a more accurate solution of Smoluchowski's equation. The current merger rate solutions are most probably sufficiently accurate for the vast majority of applications.

11 pages, submitted to MNRAS

References in corpus (8)

• The halo mass function from the dark ages through the present day
• Generating Dark Matter Halo Merger Trees
• The Nearly Universal Merger Rate of Dark Matter Haloes in Lambda-CDM Cosmology
• Constructing Merger Trees that Mimic N-Body Simulations
• Self-Consistent Theory of Halo Mergers
• The Epoch of Reionization
• The statistical properties of LCDM halo formation
• Supermassive Black Hole Merger Rates: Uncertainties from Halo Merger Theory

Cited by in corpus (6)

• Galaxy Formation Theory
• The impact of dark matter cusps and cores on the satellite galaxy population around spiral galaxies
• Galaxy Formation Spanning Cosmic History
• The Mass Function of Unprocessed Dark Matter Halos and Merger Tree Branching Rates
• The Cosmic Evolution of Halo Pairs: I. Global Trends
• Smoluchowski Coagulation Equation and the Evolution of Primordial Black Hole Clusters