Improving estimates to Harnack inequalities
arXiv:0911.0947 · doi:10.1112/plms/pdp002
Abstract
We consider operators of the form , where is an elliptic operator and is a singular potential, defined on a smooth bounded domain with Dirichlet boundary conditions. We allow the boundary of to be made of various pieces of different codimension. We assume that has a generalized first eigenfunction of which we know two sided estimates. Under these assumptions we prove optimal Sobolev inequalities for the operator , we show that it generates an intrinsic ultracontractive semigroup and finally we derive a parabolic Harnack inequality up to the boundary as well as sharp heat kernel estimates.