Date of Original Version
The final publication is available at Springer via http://dx.doi.org/10.1007/s00440-015-0617-9
Abstract or Description
It is well known that on long time scales the behaviour of tracer particles diffusing in a cellular flow is effectively that of a Brownian motion. This paper studies the behaviour on “intermediate” time scales before diffusion sets in. Various heuristics suggest that an anomalous diffusive behaviour should be observed. We prove that the variance on intermediate time scales grows like O(t√). Hence, on these time scales the effective behaviour can not be purely diffusive, and is consistent with an anomalous diffusive behaviour.
Probability Theory and Related Fields, 2015, 1-34.