Light Higgsino Dark Matter from Non-thermal Cosmology
  We study the scenario of higgsino dark matter in the context of a
non-standard cosmology with a period of matter-domination prior to Big-Bang
nucleosynthesis. Matter-domination changes the dark matter relic abundance if
it ends via reheating to a temperature below the higgsino thermal freeze-out
temperature. We perform a model independent analysis of the higgsino dark
matter production in such scenario. We show that light higgsino-type dark
matter is possible for reheating temperatures close to 1 GeV. We study the
impact of dark matter indirect detection and collider physics in this context.
We show that Fermi-LAT data rules out non-thermal higgsinos with masses below
300 GeV. Future indirect dark matter searches from Fermi-LAT and CTA would be
able to cover essentially the full parameter space. Contrary to the thermal
case, collider signals from a 100 TeV collider could fully test the non-thermal
higgsino. In the second part of the paper we discuss the motivation of such
non-thermal cosmology from the perspective of string theory with late-time
decaying moduli for both KKLT and LVS moduli stabilization mechanisms. We
describe the impact of embedding dark matter higgsino in these scenarios.
