Region visited by a spherical Brownian particle in the presence of an absorbing boundary

Phys Rev E Stat Nonlin Soft Matter Phys. 2001 Dec;64(6 Pt 1):062104. doi: 10.1103/PhysRevE.64.062104. Epub 2001 Nov 26.

Abstract

We calculate the time dependence of the average volume of a Wiener sausage in the presence of an absorbing boundary in one and three dimensions. In one dimension it is shown that the presence of an absorbing point reduces the time dependence of the average span from being proportional to sqrt[t] in an unbounded space, to being proportional to ln(t) at long times. In three dimensions the average volume increases as sqrt[t] at long times rather than being proportional to t as in free space.