Uncertainties in the Prediction of the Relic Density of Supersymmetric Dark Matter

One of the very attractive features of the minimal supersymmetric standard model is that it provides a natural candidate for cold dark matter. Cosmology, and in particular the measurement of the relic density of dark matter then put some strong constraints on the supersymmetric model. For example, WMAP [1] which at 2σ constrains the relic density in the range .094 < Ωh < .129 points to very specific scenarios [2]. Within the context of mSUGRA models, the favoured scenarios are slepton coannihilation, heavy Higgs annihilation and Higgsino LSP. The latter occurs in the focus point region with heavy scalars. Predictions for the relic density depend sensitively on the details of the supersymmetric models but also on some assumptions on the cosmological model. Assuming the LHC will discover supersymmetry, the question then is whether one can make precise predictions on the value of the relic density of dark matter, hence confront the cosmological model.