Searching for models of de Sitter quantum phenomena in two-dimensions

by Benjamin Pethybridge

Wednesday 12 Nov 2025, 16:00 → 17:00 Europe/Rome

0M04

We develop tools for quantum field theory on a fixed de Sitter background and discuss the use of two dimensional models to understand the microscopic degrees of freedom of gravity and matter in de Sitter spacetime.

We will first consider the role of unitary irreducible representations (UIRs) in understanding the spectrum of allowed quantum states in de Sitter spacetimes. Drawing on the similarities between the two- and four- dimensional cases we focus on a particular series of representations of the de Sitter isometry group: the discrete series representations of SL(2, R). Focusing on theories with states and operators transforming in these representations, we are led to a highly constrained gauge theory, describing non-propagating gravity coupled to matter. In the outlook we will make a conjecture that the microscopic degrees of freedom of the bulk theory may be described in terms of a quantum-mechanical model.