Fingerprints of the early universe

          @misc{ scivideos_PIRSA:08110021,
            doi = {10.48660/08110021},
            url = {https://pirsa.org/08110021},
            author = {Peiris, Hiranya},
            keywords = {Cosmology},
            language = {en},
            title = {Fingerprints of the early universe},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2008},
            month = {dec},
            note = {PIRSA:08110021 see, \url{https://scivideos.org/pirsa/08110021}}
          }
          

Abstract

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.