Theory HEP Seminar

DBI Inflation: Cold vs Warm

Yi-Fu Cai

Arizona State University

In this talk, I will simply review developments in string cosmology, especially focus on DBI inflation which aims at circumventing the eta-problem. However, the simplest single field DBI model can not explain current observations consistently. Therefore, we generalize the model into a picture involving multiple relativistic branes, and obtained sizable local and equilateral non-gaussianities. It also predicts a scale-invariant spectrum of entropy perturbation, and thus has interesting implication to curvaton scenario. Another important issue of brane inflation is its exiting into radiation era. I will introduce a warm version of brane inflation, and then talk about its cosmological perturbation and show how it circumvents inconsistency problem of usual version.