D. Neuenschwander et R. Schott, ON THE LOCAL AND ASYMPTOTIC-BEHAVIOR OF BROWNIAN-MOTION ON SIMPLY CONNECTED NILPOTENT LIE-GROUPS, Journal of theoretical probability, 8(4), 1995, pp. 795-806
The aim of this paper is to study the local and asymptotic behavior of
Brownian motion on simply connected nilpotent Lie groups. We carry ov
er a qualitative version of the Erdos-Renyi law of large numbers for B
rownian motion to simply connected step 2-nilpotent Lie groups. The me
thod applied gives rise to a proof for qualitative results concerning
the modulus of continuity of Brownian motion on simply connected step
3- resp. step 2-nilpotent Lie groups without using the Ventsel-Freidli
n theory as in Baldi.((1, 2))