PIRSA:21050009

Matter-driven phase transition in lattice quantum gravity

APA

Gorlich, A. (2021). Matter-driven phase transition in lattice quantum gravity . Perimeter Institute. https://pirsa.org/21050009

MLA

Gorlich, Andrzej. Matter-driven phase transition in lattice quantum gravity . Perimeter Institute, May. 06, 2021, https://pirsa.org/21050009

BibTex

          @misc{ pirsa_21050009,
            doi = {},
            url = {https://pirsa.org/21050009},
            author = {Gorlich, Andrzej},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Matter-driven phase transition in lattice quantum gravity },
            publisher = {Perimeter Institute},
            year = {2021},
            month = {may},
            note = {PIRSA:21050009 see, \url{https://pirsa.org}}
          }
          

Abstract

The model of Causal Dynamical Triangulations (CDT) is a background-independent and diffeomorphism-invariant approach to quantum gravity,

which provides a lattice regularization of the formal gravitational path integral. The framework does not involve any coordinate system and employs only geometric invariants. For a Universe with toroidal spatial topology, we can introduce coordinates using classical scalar fields with periodic boundary conditions with a jump. The field configurations reveal pictures of cosmic voids and filaments surprisingly similar to the ones observed in the present-day Universe. I will discuss the impact of dynamical matter fields on the geometry of a typical quantum universe in the four-dimensional CDT model and explain several observed phenomena. In particular, a phase transition is triggered by the change of the scalar field jump amplitude. This discovery may have important consequences for quantum universes with non-trivial topology since the phase transition can change the topology to a simply connected one.