Emergent unitarity in de Sitter from matrix integrals

A bstract We study Jackiw-Teitelboim gravity with positive cosmological constant as a model for de Sitter quantum gravity. focus on the mechanics of at past and future infinity. There is Hilbert space asymptotic states an infinite-time evolution operator between far future. This not unitary, although we find that it acts unitarily subspace up to non-perturbative corrections. These corrections come from processes which involve changes in spatial topology, including nucleation baby universes. significant evidence this 1+1 dimensional dual 0+0 matrix integral double-scaled limit. So bulk mechanics, approximately unitary evolution, emerge classical integral. emergence robust consequence level repulsion eigenvalues along double scaling limit, so rather universal random theory.