Anomalous diffusion in comb-shaped domains and graphs

Autor: Gautam Iyer, James Nolen, Robert L. Pego, Samuel Cohn
Rok vydání: 2020
Předmět:
Zdroj: Communications in Mathematical Sciences. 18:1815-1862
ISSN: 1945-0796
1539-6746
DOI: 10.4310/cms.2020.v18.n7.a2
Popis: In this paper we study the asymptotic behavior of Brownian motion in both comb-shaped planar domains, and comb-shaped graphs. We show convergence to a limiting process when both the spacing between the teeth \emph{and} the width of the teeth vanish at the same rate. The limiting process exhibits an anomalous diffusive behavior and can be described as a Brownian motion time-changed by the local time of an independent sticky Brownian motion. In the two dimensional setting the main technical step is an oscillation estimate for a Neumann problem, which we prove here using a probabilistic argument. In the one dimensional setting we provide both a direct SDE proof, and a proof using the trapped Brownian motion framework in Ben Arous \etal (Ann.\ Probab.\ '15).
47 pages, 4 figures
Databáze: OpenAIRE