SUSY-GUTs, SUSY-Seesaw and the neutralino dark matter

We will consider a SUSY-SU(5) with one right-handed neutrino with a large top like Yukawa coupling. Assuming universal soft masses at high scale we compute the low-energy spectrum and subsequently the neutralino LSP relic density taking also into consideration SU(5) as well as the see-saw running effects above the gauge coupling unification scale. We found that there exists no viable region in parameter space for tan beta less than or similar to 35. The (T) over tilde coannihilation process starts becoming efficient for tan beta greater than or similar to 35-40. However, this process is significantly constrained by the limited range in which the stau is lighter than the neutralino. Infact, for a given tan beta we find that there exists an upper bound on the lightest neutralino mass (M-chi 1(0)) in this region. The A-pole funnel region appears at very large tan beta similar or equal to 45-50, while the focus-point region does not make an appearance till large (m(0),M-1/2), namely a few TeV. Large A(0) terms at high scale can lead to extended regions consistent with WMAP constraints and remove the upper bounds in the stau coannihilation regions.