Diffeomorphism symmetry, triangulation independence and constraints in discrete gravity

          @misc{ pirsa_PIRSA:10030027,
            doi = {10.48660/10030027},
            url = {https://pirsa.org/10030027},
            author = {Dittrich, Bianca},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Diffeomorphism symmetry, triangulation independence and constraints in discrete gravity},
            publisher = {Perimeter Institute},
            year = {2010},
            month = {mar},
            note = {PIRSA:10030027 see, \url{https://pirsa.org}}
          }
          

Abstract

Diffeomorphism symmetry is the underlying symmetry of general relativity and deeply intertwined with its dynamics. The notion of diffeomorphism symmetry is however obscured in discrete gravity, which underlies most of the current quantum gravity models. We will propose a notion of diffeomorphism symmetry in discrete models and find that such a symmetry is weakly broken in many models. This is connected to the problem of finding a consistent canonical dynamics for discrete gravity. Finally we will discuss methods to construct models with exact symmetries and elaborate on the connection between diffeomorphism symmetry and triangulation independence.