Bouncing alternatives to inflation

          @misc{ scivideos_PIRSA:10050009,
            doi = {10.48660/10050009},
            url = {https://pirsa.org/10050009},
            author = {Peter, Patrick},
            keywords = {Cosmology},
            language = {en},
            title = {Bouncing alternatives to inflation},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2010},
            month = {may},
            note = {PIRSA:10050009 see, \url{https://scivideos.org/index.php/pirsa/10050009}}
          }
          

Abstract

Although inflation is, by far, the best known mechanism to explain the observed properties of our Universe, there is still some room for alternative models, most of which implying a contracting phase preceding the current expanding one. Both phases are connected by a bounce at which the expansion rate must vanish. General relativity can only produce such a phase provided the spatial curvature is positive, in contradiction with the current observations. I will discuss the lines along which one can modify either the matter or the gravity sector (or both) in order to implement a bounce, and show the generic observable cosmological consequences it can induce, in particular in the microwave background.