Special Session 75: Recent developments in Nonlinear PDEs, non-uniformly elliptic problems and related topics

Boundary weak Harnack estimates and regularity for elliptic PDE in divergence form

Boyan Sirakov
PUC-Rio
Brazil
Co-Author(s):    Fiorella Rend\`on and Mayra Soares
Abstract:
We obtain a global extension of the classical weak Harnack inequality which extends and quantifies the Hopf-Oleinik boundary-point lemma, for uniformly elliptic equations in divergence form. Among the consequences is a boundary gradient estimate, due to Krylov and well-studied for non-divergence form equations, but completely novel in the divergence framework. Another consequence is a new more general version of the Hopf-Oleinik lemma.