I will review recent progress in testing with cosmological data the inflationary hypothesis for describing the very early universe. I will present snapshots of different aspects of confronting the theory with data, including a \'bottom-up\' approach: the latest results from a systematic reconstruction of the inflationary dynamics; and a \'top- down\' approach: testing specific string theoretic constructions that attempt to implement inflation, while predicting distinctive observables not found in simple field-theory models. I will discuss the ambiguities inherent in attempting to quantify generic predictions of the inflationary \'paradigm\' (as opposed to the predictions of specific models). Finally, I will discuss (in a manner accessible to theoreticians) the astrophysical complexities underlying an observational program to look for primordial tensor modes that will discriminate between inflation and alternative theories.


Talk Number PIRSA:08110021
Speaker Profile Hiranya Peiris