I work in geometric analysis, emphasizing connections with general relativity. Einstein’s theory of general relativity describes the universe as a spacetime, which is a four-dimensional continuum containing all points and events, past, present and future. Gravitational effects (for instance, due to a black hole) manifest through the curvature of spacetime, and thus geometry plays an important role in the theory. My research typically involves scalar curvature and explores connections between mass and geometry, including “quasi-local” mass and the total “ADM” mass of a spacetime. My current interests include convergence of sequences of asymptotically flat manifolds, Bartnik’s quasi-local mass conjectures, and codimension-two geometric flows within a spacetime.