Unitarizing Higgs inflation

by Hyun Min Lee

Friday 8 Oct 2010, 11:30 → 12:30 Europe/Zurich

Auditoire 234 (Geneva University)

We consider a simple extension of the Standard Model Higgs inflation with one new real-scalar field in which there is no unitarity problem up to the Planck scale. The new scalar field, the so called sigma field, is responsible for completing the Higgs inflation by linearizing the Higgs kinetic term in Einstein frame just as the non-linear sigma model is unitarized into its linear one. In this setup, both the Higgs field and the sigma field participate in the inflationary dynamics, following the flat direction of the potential. The mass of the heavy field is of order the unitarity cutoff of the original Higgs inflation, varying with the background scalar field values. We obtained the same slow-roll parameters and spectral index as in the original Higgs inflation but found that the inflation energy depends on the Higgs self-coupling as well as the unknown couplings of the sigma field.