Experimental relevance of low reheating temperature cosmologies

TL;DR

This paper explores how low reheating temperature cosmologies can significantly alter relic particle densities, impacting dark matter and neutrino physics in ways relevant to upcoming experiments.

Contribution

It investigates the effects of non-standard pre-Big Bang Nucleosynthesis conditions on relic particle densities, challenging assumptions of the standard cosmological model.

Findings

Relic densities of neutralinos can vary widely in low reheating scenarios.

Sterile neutrinos with large mixings become cosmologically viable.

Implications for dark matter and neutrino experiments are significant.

Abstract

Standard simple assumptions are usually made about the pre-Big Bang Nucleosynthesis epoch, from which we do not have observations. Modifying these assumptions, the predicted density of relic particles such as neutralinos and sterile neutrinos can be very different from that in the standard case. For example, neutralinos could have the dark matter density in (almost) any supersymmetric model, and sterile neutrinos with mixings large enough to be soon detected in neutrino experiments would become cosmologically acceptable. These possibilities are important in view of what the LHC, and neutrino experiments could soon find.