Special Session 128: 

Free singularities in optimal transport

Jun Kitagawa
Michigan State University
USA
Co-Author(s):    Robert McCann
Abstract:
Regularity of solutions in the optimal transport problem require very rigid hypotheses (e.g., convexity of certain sets). In more general cases one can consider the question of partial regularity, i.e. in-depth analysis of the structure of singular sets. In this talk I will discuss finer structure of the set of ``free singularities`` which arise in an optimal transport problem from a connected set to a disconnected set. Such results are proven via a non-smooth implicit function theorem for convex functions, which is of independent interest. Time permitting, I will also discuss an application of this analysis to a stability result for optimal transport maps under perturbations of the target measure. This talk is based on joint work with Robert McCann.