Speaker
Description
Spin foam quantum gravity describes quantum space-time as a sum over (pre-)geometric configurations encoded in group theoretic labels. In absence of experimental data, it is therefore crucial to establish connection to classical, continuum physics. While the connection to discrete (Regge) gravity is well established for small discretisations, large triangulations are far less explored. To learn about their geometry, extraction of observables, e.g. the spectral dimension, via numerical simulations is indispensable. In this talk, I will briefly review the numerical challenges and progress made in the last years. Then I present the so-called hybrid representation of spin foams that allows us to understand spin foams as a superposition of non-matching building blocks in the semi-classical regime. This allows us to explore two directions: on the one hand, we can define an effective model utilizing semi-classical amplitudes, which will give indications which configurations dominate in the path integral. On the other hand, we use it to define probability distribution (for intertwiner labels) that can be used for Monte Carlo simulations.
