Hybrid Inflation and Supergravity

Hybrid inflation is a natural scenario in the absence of supersymmetry. In the context of supergravity, however, it has to face the naturalness problems of the initial conditions and of the adequate suppression of the inflaton mass. Both can be successfully addressed in a class of models involving Kaehler potentials associated with products of SU(1,1)/U(1) Kaehler manifolds and "decoupled" fields acquiring large vacuum expectation values through D-terms.