Quintessential Kination and Thermal Production of SUSY e-WIMPs

TL;DR

This paper studies how a kination-dominated phase affects the thermal production of SUSY e-WIMPs, showing it can evade gravitino constraints and produce viable dark matter candidates.

Contribution

It demonstrates that a quintessential kination phase significantly alters the thermal abundance of SUSY e-WIMPs, enabling viable dark matter scenarios.

Findings

Unstable gravitino constraints are evaded in kination.

Stable gravitino abundance is insufficient for dark matter.

Axino abundance can meet dark matter constraints at high reheating temperatures.

Abstract

The impact of a kination-dominated phase generated by a quintessential exponential model on the thermal abundance of Supersymmetric (SUSY) extremely Weekly Interacting Massive Particles (e-WIMPs) is investigated. For values of the quintessential energy-density parameter on the eve of nucleosynthesis close to its upper bound, we find that: (i) the gravitino constraint is totally evaded for unstable gravitinos; (ii) the thermal abundance of stable gravitinos is not sufficient to account for the cold dark matter of the universe; (iii) the thermal abundance of axinos can satisfy the cold dark matter constraint for values of the initial (``reheating'') temperature well above those required in the standard cosmology.