Ricci Flow under Kato-type curvature lower bound

Abstract

In this work, we extend the existence theory of non-collapsed Ricci flows from point-wise curvature lower bound to Kato-type lower bound. As an application, we prove that compact three dimensional non-collapsed strong Kato limit space is homeomorphic to a smooth manifold. The result also holds in higher dimension under uniform strong Kato lower bound of 1-isotropic curvature. We also use the Ricci flow smoothing to study stability problem in scalar curvature geometry.