A microscopic realization of dS3

I will explain a recently proposed holographic scenario for pure dS3 Einstein quantum gravity. The dual description is a double-scaled matrix model, which is capable of capturing bulk cosmological correlators integrated over the metric at future infinity in order to define gauge-invariant observables. Moreover the matrix model has precisely the right number of degrees of freedom to account for the de Sitter entropy associated with the cosmological horizon seen by an observer. A key step in the logic is a reformulation of the gravity theory in terms of a novel topological quantum field theory. Based on work with Lorenz Eberhardt and Beatrix Mühlmann, building on previous work with Victor Rodriguez.