Regge Dilaton Gravity from BF Theory

Abstract: In this work we investigate the relation between gauge and geometric descriptions of two-dimensional dilaton gravity at the level of discrete path integrals. We develop a Regge discretization of Euclidean two-dimensional dilaton gravity using homogeneously curved simplices, as well as a ribbon refined discretization of two-dimensional BF theory adapted to homogeneously curved spacetimes. For Euclidean signature and vanishing or negative cosmological constant we show how the ribbon BF discretization, through appropriate gauge fixings, leads to the Regge dilaton gravity formulation. The resulting correspondence makes explicit how a geometric Regge path integral with its associated measure emerges from its gauge theoretic formulation.