On the possibility of chaotic inflation from a softly-broken superconformal invariance

Abstract

It has recently been suggested by Papantonopoulos, Uematsu and Yanagida that chaotic inflation can occur in a non-linear sigma model. The non-minimal coupling of the real part φ and the imaginary part ξ of a complex scalar field is supposed automatically to give the correct initial conditions for inflation, the potential for which is provided by a soft symmetry breaking term Image. We show that the non-minimal coupling is not essential, but that fine tuning in the potential is, in the sense that m2less, approximate2x10−10. We comment on the relevance of the model to superstring theory.