Is imaginary Starobinsky model real?

Abstract

We investigate the recently proposed possibility of chaotic inflation with\nrespect to the imaginary part of the field T in a supersymmetric embedding of\nthe Starobinsky model. We show that the stage of rapid expansion driven by Im T\nin this model ends almost instantly, and the subsequent stages of inflation are\ndriven by the real part of the field T, as in the standard Starobinsky model.\nThus, the Starobinsky model and its supersymmetric generalizations remain\ndisfavored by the recent BICEP2 data.\n