Low scale inflation and the immediate heavy curvaton decay

Abstract

The end of a thermal inflation era, driven by the rolling of a flaton field coupled to the curvaton, cause a huge increment in the curvaton mass and decay rate while the curvaton is still frozen. It is shown that, if this increment is enough for the curvaton to immediately decay, low scale inflation with Hubble parameter H_\ast \sim 10^3 GeV is achieved for more natural values of the flaton-curvaton coupling constant \lambda (10^{-10} \lsim \lambda \lsim 10^{-4}) and the curvaton bare mass m_\sigma (m_\sigma \lsim 1 GeV).