Leptogenesis in supersymmetric hybrid inflation

The non-supersymmetric as well as the supersymmetric hybrid inflationary model is reviewed. The scenario of baryogenesis via a primordial leptogenesis is discussed and the role of the non-perturbative electroweak sphaleron effects is analyzed in detail. A supersymmetric model based on a left-right symmetric gauge group, which ‘naturally’ leads to hybrid inflation, is presented. The μ problem is solved, in this model, and the baryon asymmetry of the universe is produced through leptogenesis. For masses of ν μ, ν τ from the small angle MSW resolution of the solar-neutrino problem and super-Kamiokande, maximal ν μ−ν τ mixing can be achieved. The required values of the relevant parameters are, however, quite small.