Consider 3-dimensional Brownian motion started on the unit sphere {|x| = 1} with initial density ρ. Let ρt be the first hitting density on the sphere {|x| = t + 1}, t > 0. Then the linear operators Tt defined by Tt ρ = ρt form a semigroup with an infinitesimal generator which is approximately the square root of the Laplacian. This paper studies the analogous situation for Brownian motion with a drift b, where b is small in a suitable scale invariant norm.
@article{urn:eudml:doc:41366, title = {Fluctuations of brownian motion with drift.}, journal = {Publicacions Matem\`atiques}, volume = {43}, year = {1999}, pages = {85-125}, mrnumber = {MR1697517}, zbl = {0934.60070}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:41366} }
Conlon, Joseph G.; Olsen, Peder. Fluctuations of brownian motion with drift.. Publicacions Matemàtiques, Tome 43 (1999) pp. 85-125. http://gdmltest.u-ga.fr/item/urn:eudml:doc:41366/