Quintessence and the relic density of neutralinos

Abstract

The archetypal model for the recently discovered dark energy component of the universe is based on the existence of a scalar field whose dynamical evolution comes down today to a non-vanishing cosmological constant. In the past—before big-bang nucleosynthesis for that matter—that scalar field could have gone through a period of kination during which the universe has expanded at a much higher pace than what is currently postulated in the standard radiation dominated cosmology. I examine here the consequences of such a period of kination on the relic abundance of neutralinos and find that the latter could be much higher—by three orders of magnitude—than what is estimated in the canonical derivation. I shortly discuss the implications of this scenario for the dark matter candidates and their astrophysical signatures.