Problems / geometry-topology
geometry-topology / Metric measure spaces; synthetic lower Ricci bounds; RCD spaces
Bi-Lipschitz charts at every regular point of a noncollapsed RCD(K,n) space
Claims that for every integer n≥2 there is Ln≥1 such that every regular point of every noncollapsed RCD(K,n) space, K∈R, has an open neighborhood Ln-bi-Lipschitz homeomorphic, with the ambient distance, to an open subset of Rn; the neighborhood depends on the space and the point. Corollary: an open set of full Hn measure containing all regular points carries a countable bi-Lipschitz atlas with Ln2 transition maps. It does NOT claim that the regular set is open, any collapsed or non-RCD statement, or regularity of the metric tensor in the charts.