Challenges of Explaining Cosmic Acceleration Through Modified Gravity

          @misc{ scivideos_PIRSA:07040011,
            doi = {10.48660/07040011},
            url = {https://pirsa.org/07040011},
            author = {},
            keywords = {Cosmology},
            language = {en},
            title = {Challenges of Explaining Cosmic Acceleration Through Modified Gravity},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2007},
            month = {apr},
            note = {PIRSA:07040011 see, \url{https://scivideos.org/pirsa/07040011}}
          }
          

Abstract

Among the possible explanations for the observed acceleration of the universe, perhaps the boldest is the idea that new gravitational physics might be the culprit. In this colloquium I will discuss some of the challenges of constructing a sensible phenomenological extension of General Relativity, give examples of some candidate models of modified gravity and survey existing observational constraints on this approach. I will conclude by discussing how we might hope to distinguish between modifications of General Relativity and dark energy as competing hypotheses to explain cosmic acceleration.