Smoothing L^ Riemannian metrics with nonnegative scalar curvature outside of a singular set

We show that any L^ Riemannian metric g on Rⁿ that is smooth with nonnegative scalar curvature away from a singular set of finite (n-) -dimensional Minkowski content, for some >2, admits an approximation by smooth Riemannian metrics with nonnegative scalar curvature, provided that g is sufficiently close in L^ to the Euclidean metric. The approximation is given by time slices of the Ricci-DeTurck flow, which converge locally in C^ to g away from the singular set.