Speaker
Andrea Calcinari
(University of Sheffield)
Description
Approaches to quantum gravity describing spacetime as emergent, i.e., as the collective behaviour of some discrete fundamental structures, must allow for quantum states which manifest semiclassical features. In this talk I present a realisation of this idea in the context of group field theory (GFT), where we depart from the familiar coherent states by studying properties of the more general Gaussian states in simple cosmological models. We show that while these states do not minimise uncertainty inequalities, they have small quantum fluctuations. I will also discuss thermal states and the interpretation of thermodynamic equilibrium, and different notions of semiclassicality in two quantisation schemes in GFT.
