A variational proof of partial regularity for optimal transportation maps

Michael Goldman (1) , F Otto (2)

1 LJLL - Laboratoire Jacques-Louis Lions
2 MPI-MiS - Max-Planck-Institut für Mathematik in den Naturwissenschaften

We provide a new proof of the known partial regularity result for the optimal transportation map (Brenier map) between two sets. Contrary to the existing regularity theory for the Monge-Ampère equation, which is based on the maximum principle, our approach is purely variational. By constructing a competitor on the level of the Eulerian (Benamou-Brenier) formulation, we show that locally, the velocity is close to the gradient of a harmonic function provided the transportation cost is small. We then translate back to the Lagrangian description and perform a Campanato iteration to obtain an ε-regularity result.

Domaines: Equations aux dérivées partielles [math.AP]

Michael Goldman, F Otto. A variational proof of partial regularity for optimal transportation maps. Annales Scientifiques de l'École Normale Supérieure, In press. ⟨hal-01504078v3⟩