IR modification of gravity and the forbidden mass range of spin-2 particles in De Sitter space

          @misc{ scivideos_PIRSA:08120047,
            doi = {10.48660/08120047},
            url = {https://pirsa.org/08120047},
            author = {Shang, Yanwen},
            keywords = {Particle Physics},
            language = {en},
            title = {IR modification of gravity and the forbidden mass range of spin-2 particles in De Sitter space},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2008},
            month = {dec},
            note = {PIRSA:08120047 see, \url{https://scivideos.org/pirsa/08120047}}
          }
          

Abstract

One of the most challenging problems in theoretical physics today is the so called cosmological constant problem. While current observations are consistent with the prediction of GR with an unexplainable tiny cosmological constant, it remains possible that it\'s the deviation of the law of gravity at large distance from Einstein\'s theory that resolves the puzzle. In this talk, I will briefly review some of the theoretical attempts we made along this line, in particular, the so called \'classically constrained gravity\' and its implications in quantum cosmology. I will also present some most recent study on massive spin-2 particles in De Sitter space, and describe a model, initially motivated by DGP theory, which allows one to explore the Higuchi forbidden mass range of the graviton on the De Sitter background.