Physics (Internal)

Low dimensional de Sitter quantum gravity

This event is part of the HET Seminar Series.

I will discuss quantum mechanical aspects of Jackiw-Teitelboim gravity on nearly two-dimensional de Sitter spacetime, and pure de Sitter gravity in three dimensions. In both cases there are only edge modes, and I will present boundary effective actions for these degrees of freedom. These include boundary gravitons on each connected component of the boundary in addition to topological degrees of freedom. These actions allow us to compute gravitational observables, like the wavefunction of the universe at future infinity or gravitational scattering, at loop level and in some cases to all orders in perturbation theory. If time allows, I will also discuss some tempting connections with random matrix theory and the Sachdev-Ye-Kitaev model.