Séminaire de Physique ThéoriquePseudoscalars, natural chaotic inflation, and their cosmological signatures
Lorenzo Sorbo (Univ. of Massachusetts)
Tuesday 15 June 2010 11:00 - Tours - Salle 1180 (Bât E2)
Pseudoscalar particles provide an elegant candidate for radiatively stable models of inflation. I will first review the observational status of pseudoscalar-driven inflation and the difficulties one faces when trying to embed these models in string theory. I will then discuss how a pseudoscalar can naturally get a quadratic potential in theories where it mixes with a 4-form. String theory naturally provides such a mixing, and the mass which arises from it is protected by the axionic shift symmetry. Since the potential is quadratic with very good approximation, this model provides a natural example of chaotic inflation. In the final part of the talk I will discuss signatures that can characterize models of pseudoscalar inflation and in particular natural chaotic inflation.