Gregory F Lawler, Cornell University Vlada Limic, University of British Columbia
Abstract
An estimate of Beurling
states that if K is a curve from 0 to
the unit circle in the complex plane,
then the probability that a Brownian motion starting
at -&epsilon reaches the unit circle without hitting
the curve is bounded above by c &epsilon^{1/2}.
This estimate is very useful in analysis of boundary behavior
of conformal maps, especially for connected but
rough boundaries.
The corresponding estimate for simple random walk was
first proved by Kesten.
In this note we extend this estimate to random walks with
zero mean, finite (3+&delta)-moment.