ADM mass for $C^0$ metrics and distortion under Ricci-DeTurck flow
Paula Burkhardt-Guim
TL;DR
This work develops a robust $C^0$-based notion of ADM-type mass for asymptotically flat manifolds, showing that a quantity $M_{C^0}$ depending only on $C^0$ data matches the classical ADM mass when it exists and, more generally, admits a well-defined limit at infinity under $C^0$-asymptotic flatness with nonnegative scalar curvature in the Ricci flow sense. By coupling a time-evolving test function under Ricci-DeTurck flow, the authors establish a controlled distortion of the local $C^0$ mass and prove monotonicity-like properties, leading to a chart-independent limit for the mass at infinity. The analysis relies on a careful synthesis of RD-flow theory, heat-kernel bounds, mollified transition maps between ends, and gluing arguments, culminating in precise finiteness criteria tied to curvature behavior along RD-flow time slices. These results pave the way for a $C^0$-positive mass framework parallel to the classical PMT, with potential implications for nonsmooth geometry and general relativity in low-regularity settings.
Abstract
We show that there exists a quantity, depending only on $C^0$ data of a Riemannian metric, that agrees with the usual ADM mass at infinity whenever the ADM mass exists, but has a well-defined limit at infinity for any continuous Riemannian metric that is asymptotically flat in the $C^0$ sense and has nonnegative scalar curvature in the sense of Ricci flow. Moreover, the $C^0$ mass at infinity is independent of choice of $C^0$-asymptotically flat coordinate chart, and the $C^0$ local mass has controlled distortion under Ricci-DeTurck flow when coupled with a suitably evolving test function.
