The Persistent Topology of Optimal Transport Based Metric Thickenings
arXiv:2109.15061 · doi:10.2140/agt.2024.24.393
Abstract
A metric thickening of a given metric space is any metric space admitting an isometric embedding of . Thickenings have found use in applications of topology to data analysis, where one may approximate the shape of a dataset via the persistent homology of an increasing sequence of spaces. We introduce two new families of metric thickenings, the -Vietoris-Rips and -Čech metric thickenings for all , which include all measures on whose -diameter or -radius is bounded from above, equipped with an optimal transport metric. The -diameter (resp. -radius) of a measure is a certain relaxation of the usual notion of diameter (resp. radius) of a subset of a metric space. These families recover the previously studied Vietoris-Rips and Čech metric thickenings when . As our main contribution, we prove a stability theorem for the persistent homology of -Vietoris-Rips and -Čech metric thickenings, which is novel even in the case . In the specific case , we prove a Hausmann-type theorem for thickenings of manifolds, and we derive the complete list of homotopy types of the -Vietoris-Rips thickenings of the -sphere as the scale increases.