Burdzy, KrzysztofBass, Richard F.2005-11-182005-11-181994Bass, R.F. & K. Burdzy. (1994). The boundary Harnack principle for non-divergence form elliptic operators. Journal of the London Mathematical Society, 50, 157-169.http://hdl.handle.net/1773/2174If L is a uniformly elliptic operator in non–divergence form, the boundary Harnack principle for the ratio of positive L–harmonic functions holds in Hölder domains of order [alpha] if [alpha] > 1/2. A counterexample shows that 1/2 is sharp. For Hölder domains of order [alpha] with [alpha is an element of the set] (0, 1], the boundary Harnack principle holds provided the domain also satisfies a strong uniform regularity condition.179681 bytesapplication/pdfen-USboundary Harnack principleHölder domainsArticle