1996/01/18 by Lisa Randall, Marin Soljacic, Randall, Lisa +3
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #astro-ph #hep-ph #hep-th
paper · pdf · doi:10.48550/arxiv.hep-ph/9601296
10 pages, revtex, epsf, this paper is a short version of hep-ph/9512439
arxiv created 1996/01/18 · arxiv updated 2009/11/30
Most models of inflation have small parameters, either to guarantee sufficient inflation or the correct magnitude of the density perturbations. In this paper we show that, in supersymmetric theories with weak scale supersymmetry breaking, one can construct viable inflationary models in which the requisite parameters appear naturally in the form of the ratio of mass scales that are already present in the theory. Successful inflationary models can be constructed from the flat-direction fields of a renormalizable supersymmetric potential, and such models can be realized even in the context of a simple GUT extension of the MSSM. We evade naive ``naturalness" arguments by allowing for more than one field to be relevant to inflation, as in ``hybrid inflation" models, and we argue that this is the most natural possibility if inflaton fields are to be associated with flat direction fields of a supersymmetric theory. Such models predict a very low Hubble constant during inflation, of order 103-104 GeV, a scalar density perturbation index n which is very close to or greater than unity, and negligible tensor perturbations. In addition, these models lead to a large spike in the density perturbation spectrum at short wavelengths.