The Sobolev Wavefront Set of the Causal Propagator in Finite Regularity

Yafet Sanchez Sanchez, Elmar Schrohe

Given a globally hyperbolic spacetime $M=\mathbb{R}\times \Sigma$ of dimension four and regularity $C^{\tau }$, we estimate the Sobolev wavefront set of the causal propagator $K_G$ of the Kle…