CHAOTIC INFLATION BASED ON AN ABELIAN D-FLAT DIRECTION

We study the inflation due to the D-flat direction of an extra U(1). This scenario is a hybrid of a right-handed sneutrino inflaton scenario and a gauge nonsinglet inflaton scenario. The inflaton is a gauge nonsinglet field which induces a right-handed neutrino mass spontaneously through an extra U(1) D-flat direction. This right-handed neutrino mass can be used to explain the solar neutrino problem. The reheating temperature resulting from the decay of the coherent oscillation of the right-handed sneutrino is sufficiently high so that the baryogenesis based on the lepton number asymmetry can be applicable. We also discuss the realistic model building.