Central limit theorems for non-symmetric random walks on nilpotent covering graphs: Part II

Autor: Ishiwata, Satoshi, Kawabi, Hiroshi, Namba, Ryuya
Rok vydání: 2018
Předmět:
Zdroj: Potential Analysis 55 (2021), 127-166
Druh dokumentu: Working Paper
DOI: 10.1007/s11118-020-09851-7
Popis: In the present paper, as a continuation of our preceding paper [10], we study another kind of central limit theorems (CLTs) for non-symmetric random walks on nilpotent covering graphs from a viewpoint of discrete geometric analysis developed by Kotani and Sunada. We introduce a one-parameter family of random walks which interpolates between the original non-symmetric random walk and the symmetrized one. We first prove a semigroup CLT for the family of random walks by realizing the nilpotent covering graph into a nilpotent Lie group via discrete harmonic maps. The limiting diffusion semigroup is generated by the homogenized sub-Laplacian with a constant drift of the asymptotic direction on the nilpotent Lie group, which is equipped with the Albanese metric associated with the symmetrized random walk. We next prove a functional CLT (i.e., Donsker-type invariance principle) in a Holder space over the nilpotent Lie group by combining the semigroup CLT, standard martingale techniques, and a novel pathwise argument inspired by rough path theory. Applying the corrector method, we finally extend these CLTs to the case where the realizations are not necessarily harmonic.
Comment: 41 pages, 2 figures. arXiv admin note: text overlap with arXiv:1806.03804"
Databáze: arXiv