Matterdriven phase transition in lattice quantum gravity Speaker(s): Andrzej Gorlich
Abstract:
The model of Causal Dynamical Triangulations (CDT) is a backgroundindependent and diffeomorphisminvariant 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 presentday Universe. I will discuss the impact of dynamical matter fields on the geometry of a typical quantum universe in the fourdimensional 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 nontrivial topology since the phase transition can change the topology to a simply connected one.
Date: 06/05/2021  2:30 pm
Series: Quantum Gravity
