Supersymmetric Dark Matter 2004

Abstract

Recent cosmological data allow to determine the universal Dark Matter (DM) density to a precision of about 10%, if a simple, well-motivated ansatz for the spectrum of primordial density perturbations is correct. Not surprisingly, a thermal neutralino χwill have the correct relic density only in ``small'' regions of parameter space. In particular, for fixed values of the other parameters, the allowed region in the (m_0, m_{1/2} plane (in mSUGRA or similar models) seems quite small, if standard assumptions about the Universe at temperature T \simeq m_χ/ 10 are correct. I argue that the allowed parameter space is actually still quite large, when all uncertainties are properly taken into account. In particular, the current lower limits on sparticle and Higgs masses that can be derived within mSUGRA do not change appreciably when the DM relic density constraint is imposed. I also show that deviating from mSUGRA does not alleviate the finetuning required to obtain the correct relic density, unless one also postulates a non-standard cosmology. Finally, I briefly discuss claimed positive evidence for particle Dark Matter.