  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.
