Burdzy, Krzysztof; Barlow, Martin T.; Bass, Richard F.
(Electronic Journal of Probability, 1997-09-24)
Let B be a Borel subset of R [to the power of] d and let p(t, x, y) be the transition densities of Brownian motion killed on leaving B. Fix x and y in B. If p(t, x, y) is positive for one t, it is positive for every value ...