PIRSA:18100057

Video URL

https://pirsa.org/18100057

Asymptotic analysis of spin foam amplitude with timelike triangles

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

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

          @misc{ scivideos_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 for Theoretical Physics},
            year = {2018},
            month = {oct},
            note = {PIRSA:18100057 see, \url{https://scivideos.org/index.php/pirsa/18100057}}
          }

Hongguang Liu University of Erlangen-Nuremberg

Talk numberPIRSA:18100057
DOI10.48660/18100057
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
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.