Quantum cosmology as automorphic dynamics

TL;DR

This paper explores quantum cosmology in three dimensions, linking Wheeler-DeWitt solutions to automorphic dynamics, Tar{T} deformations, and automorphic forms, providing new insights into the Hartle-Hawking state.

Contribution

It introduces a novel automorphic dynamics framework for 3D quantum cosmology, connecting it to Tar{T} deformations and automorphic forms, and offers a new interpretation of the Hartle-Hawking state.

Findings

Wheeler-DeWitt equation solved perturbatively

Dynamics reduces to a particle on moduli space

Spectral decomposition of the Hartle-Hawking state

Abstract

We revisit pure quantum cosmology in three dimensions. The Wheeler-DeWitt equation can be solved perturbatively and the dynamics reduces to a particle on moduli space. Its time evolution is equivalent to the $T\overline{T}$ deformation. Focusing on spacetimes with torus slices, we show that inflationary cosmologies correspond to particle trajectories in Artin's billiard. The resulting automorphic dynamics is developed both from a first and second quantized perspectives. Our main application is to give an interpretation for the Hartle-Hawking state which is here the analytic continuation of the Maloney-Witten partition function. We obtain its spectral decomposition and an exact representation as an average involving the M\"obius function.