1:00 pm Monday 23 September 2002
In this talk, I will discuss the possibility where comparable amount of both adiabatic and isocurvature perturbations are allowed to be produced during the inflation and remain after reheating due to the conversion of this isocurvature perturbation created during the inflation into the adiabatic perturbation when the non-inflaton field starts oscillation well after reheating era. This will be discussed through a specific potential where one scalar field is responsible for inflation and the other has a rather weak coupling to the other fields so that it is not thermalized in reheating process for the isocurvature perturbation to persist even after reheating. After a brief review on a general formalism for an analytic growing solution to obtain the curvature and entropy perturbations in existence of two fields, the evolutions of these perturbations after horizon exit are examined. I will also look into the perturbation correlations and especially investigate the maximal correlation scenario and `curvaton scenario' as a special case of this scenario, and show explicitly when this can happen using the analytical solution for the perturbations.