Curvatons in the minimally supersymmetric standard model

Abstract

Curvaton is an effectively massless field whose energy density during inflation is negligible but which later becomes dominant. This is a novel mechanism to generate the scale invariant perturbations. I discuss the possibility that the curvaton could be found among the fields of the minimally supersymmetric standard model (MSSM), which contains a number of flat directions along which the renormalizable potential vanishes. The requirements of late domination and the absence of damping of the perturbations pick out essentially a unique candidate for the MSSM curvaton. One must also require that inflation takes place in a hidden sector. If the inflaton energy density can be radiated into extra dimensions, many constraints can be relaxed, and the simplest flat direction consisting of the Higgses H_u and H_d would provide a working example of an MSSM curvaton.