PIRSA:18100057

Asymptotic analysis of spin foam amplitude with timelike triangles

Liu, H. (2018). Asymptotic analysis of spin foam amplitude with timelike triangles . Perimeter Institute. https://pirsa.org/18100057

Liu, Hongguang. Asymptotic analysis of spin foam amplitude with timelike triangles . Perimeter Institute, Oct. 04, 2018, https://pirsa.org/18100057 

          @misc{ pirsa_PIRSA:18100057,
            doi = {10.48660/18100057},
            url = {https://pirsa.org/18100057},
            author = {Liu, Hongguang},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Asymptotic analysis of spin foam amplitude with timelike triangles },
            publisher = {Perimeter Institute},
            year = {2018},
            month = {oct},
            note = {PIRSA:18100057 see, \url{https://pirsa.org}}
          }

Hongguang Liu

University of Erlangen-Nuremberg

Talk number
PIRSA:18100057
Collection
Talk Type
Subject
Abstract

The large j asymptotic behavior of 4-dimensional spin foam amplitude is investigated for the extended spin foam model (Conrady-Hnybida extension) on a simplicial complex. We study the most general situation in which timelike tetrahedra with timelike triangles are taken into account. The large j asymptotic behavior is determined by critical configurations of the amplitude. We identify the critical configurations that correspond to the Lorentzian simplicial geometries with timelike tetrahedra and triangles. Their contributions to the amplitude are phases asymptotically, whose exponents equal to Regge action of gravity. The amplitude also contains critical configurations corresponding to non-degenerate split signature 4-simplices and degenerate vector geometries.