On the Boundary Point Principle for divergence-type equations
Darya Evgen'evna Apushkinskaya, Alexander Il'ich Nazarov · Rendiconti Lincei Matematica e Applicazioni · 2019
We provide some versions of the Zaremba–Hopf–Oleinik boundary point lemma for general elliptic and parabolic equations in divergence form under the sharp requirements on the coefficients of equations and on the boundaries of domains.