Partial regularity for solutions to subelliptic eikonal equations
Paolo Albano, Piermarco Cannarsa, Teresa Scarinci · Comptes Rendus Mathématique · 2018
On a bounded domain Ω in the Euclidean space R n , we study the homogeneous Dirichlet problem for the eikonal equation associated with a system of smooth vector fields, which satisfies Hörmander's bracket generating condition. We prove that the solution is smooth in the complement of a closed set of Lebesgue measure zero.