Abundance of cosmological relics in low-temperature scenarios

2006/03/31 by Manuel Drees, Hoernisa Iminniyaz, M. Kakizaki +1 · 1 citation
Physics and Astronomy · #Ansatz #Astrophysics #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Geology #Mathematical physics #Particle (ecology) #Physics #Statistical physics #Thermal #Thermal equilibrium #Thermodynamics #astro-ph #hep-ph

paper · pdf · doi:10.1103/physrevd.73.123502

published as Phys.Rev. D73 (2006) 123502 · 26 pages, 8 figures, comments added, to appear in Phys. Rev. D

arxiv created 2006/05/16 · openalex publication_date 2006/06/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We investigate the relic density n_\ensuremathχ of nonrelativistic long-lived or stable particles \ensuremathχ in cosmological scenarios in which the temperature T is too low for \ensuremathχ to achieve full chemical equilibrium. The case with a heavier particle decaying into \ensuremathχ is also investigated. We derive approximate solutions for n_\ensuremathχ(T) which accurately reproduce numerical results when full thermal equilibrium is not achieved. If full equilibrium is reached, our ansatz no longer reproduces the correct temperature dependence of the \ensuremathχ number density. However, it does give the correct final relic density, to an accuracy of about 3% or better, for all cross sections and initial temperatures.

Citations

• Massive particle decay and cold dark matter abundance
• Production of Massive Stable Particles in Inflaton Decay
• Particle dark matter: evidence, candidates and constraints
• First‐Year Wilkinson Microwave Anisotropy Probe ( WMAP ) Observations: Determination of Cosmological Parameters
• Particle Physics Models of Inflation and the Cosmological Density Perturbation
• Towards the theory of reheating after inflation

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