Quantum Spacetime from Lattice Gravity à la CDT

          @misc{ pirsa_PIRSA:19110084,
            doi = {10.48660/19110084},
            url = {https://pirsa.org/19110084},
            author = {Loll, Renate},
            keywords = {Cosmology, Quantum Fields and Strings, Quantum Gravity},
            language = {en},
            title = {Quantum Spacetime from Lattice Gravity {\`a} la CDT},
            publisher = {Perimeter Institute},
            year = {2019},
            month = {nov},
            note = {PIRSA:19110084 see, \url{https://pirsa.org}}
          }
          

Abstract

Causal Dynamical Triangulations (CDT) is a candidate theory for quantum gravity, formulated nonperturbatively as the scaling limit of a lattice theory in terms of triangulated spacetimes. An important feature of this approach is its elegant resolution of the problem of diffeomorphism symmetry in the full, background-free quantum theory. This has enabled the concrete computation of geometric observables in a highly nonperturbative, Planckian regime, an important step in putting quantum gravity on a quantitative footing, and understanding the structure of quantum spacetime. While the need to find quantum observables describing this regime is common to all approaches, CDT provides a concrete testing ground for implementation and measurements. In particular, a new notion of quantum Ricci curvature has opened a new window on the counterintuitive properties of quantum geometry.