Inflation caused by a potential valley with CP violation

Abstract

We propose an inflation scenario caused by an inflaton identified with a potential valley which brings about $CP$ violation in the standard model (SM). If singlet scalars have nonminimal couplings with the Ricci scalar in a suitable way, favorable inflation could be derived through the potential valley composed of such scalars. We study dynamics of the scalars during and after the inflation, which suggests that it could be described as a single field inflation approximately. If these scalars make suitable ingredients of the SM couple with vectorlike fermions and right-handed neutrinos, a CKM phase could be induced and also leptogenesis could occur successfully even at a rather low reheating temperature.