A geometric second-order-rectifiable stratification for closed subsets of Euclidean space
arXiv:1703.09561 · doi:10.2422/2036-2145.201703_021
Abstract
Defining the -th stratum of a closed subset of an dimensional Euclidean space to consist of those points, where it can be touched by a ball from at least linearly independent directions, we establish that the -th stratum is second-order rectifiable of dimension and a Borel set. This was known for convex sets, but is new even for sets of positive reach. The result is based on a new criterion for second-order rectifiability.
13 pages. v2: corrected a typographical error in the introduction, and updated the affiliation of the first author