Axions and the dark matter of the universe

Spin(10) axion models are constructed which offer the possibility that axions comprise all or a significant part of the dark matter of the Universe

Mu Problem and Hybrid Inflation in Supersymmetric SU(2)_L x SU(2)_R x U(1)_B-L

We present a solution of the mu problem within a supersymmetric model based on the SU(2)_L x SU(2)_R x U(1)_{B-L} gauge group. We show that this solution implies a built-in hybrid inflationary scenario, which may result in a successful baryogenesis via leptogenesis. Baryon number is essentially conserved as a result of an R-symmetry. Neutrinos with mass in the eV range can provide the `hot' dark matter component.Comment: 11 pages, LaTeX, RevTeX, no fig

Supersymmetric And Smooth Hybrid Inflation In The Light Of WMAP3

In their minimal form both supersymmetric and smooth hybrid inflation yield a scalar spectral index n_s close to 0.98, to be contrasted with the result n_s=0.951+0.015-0.019 from WMAP3. To realize better agreement, following hep-ph/0604198, we extend the parameter space of these models by employing a non-minimal Kaehler potential. We also discuss non-thermal leptogenesis by inflaton decay and obtain new bounds in these models on the reheat temperature to explain the observed baryon asymmetry.Comment: 21 pages, 12 figures, revtex4. v2: minor revisions, additional references, to appear in PR