Going beyond de Sitter

          @misc{ scivideos_PIRSA:10100081,
            doi = {10.48660/10100081},
            url = {https://pirsa.org/10100081},
            author = {Prokopec, Tomislav},
            keywords = {Cosmology},
            language = {en},
            title = {Going beyond de Sitter},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2010},
            month = {oct},
            note = {PIRSA:10100081 see, \url{https://scivideos.org/pirsa/10100081}}
          }
          

Abstract

De Sitter space is a maximally symmetric space, and any (time dependent) backreaction necessarily breaks the symmetry. On the other hand, the backreaction in FLRW spaces (which, from the cosmological perspective, are more realistic spaces) respects the symmetries of the background space. One could therefore argue that it is more natural to study the backreaction on quasi-de Sitter spaces, and more generally on FLRW spaces. As examples, I will present our results on the one loop (Hubble) effective potential calculation, and the one loop stress energy calculation. We find that the backreaction from infrared modes can be important if a massless scalar couples nonminimally to the Ricci with a negative coupling, and if the Universe expands faster than exponentially.