Direct detection of neutralino dark matter in nonstandard cosmologies

We compute the neutralino direct detection rate in nonstandard cosmological scenarios where neutralinos account for the dark matter of the Universe. Significant differences are found when such rates are compared with those predicted by the standard cosmological model. For b-ino-like neutralinos, the main feature is the presence of additional light (mx ≤ 40 GeV) and heavy (mx≥ 600 GeV) neutralinos with detection rates within the sensitivity of future dark matter experiments. For Higgsinolike and W-ino-like neutralinos lighter than mx ~ 1 TeV, enhancements of more than 2 orders of magnitude in the largest detection rates are observed. Thus, if dark matter is made up of neutralinos, the prospects for their direct detection are in general more promising than in the standard cosmology.