Mixing of fast random walks on dynamic random permutations

• 成果类型: Article; Early Access
• 署名作者: Avena, Luca; van der Hofstad, Remco; den Hollander, Frank; Nagy, Oliver
• 署名单位: University of Florence; Eindhoven University of Technology; Leiden University; Leiden University - Excl LUMC
• 刊物名称: PROBABILITY THEORY AND RELATED FIELDS
• ISSN/ISSBN: 0178-8051
• DOI: 10.1007/s00440-025-01375-8
• 发表日期: 2025
• 关键词: cutoff; models; times; cycles

摘要

We analyse the mixing profile of a random walk on a dynamic random permutation, focusing on the regime where the walk evolves much faster than the permutation. Two types of dynamics generated by random transpositions are considered: one allows for coagulation of permutation cycles only, the other allows for both coagulation and fragmentation. We show that for both types, after scaling time by the length of the permutation and letting this length tend to infinity, the total variation distance between the current distribution and the uniform distribution converges to a limit process that drops down in a single jump. This jump is similar to a one-sided cut-off, occurs after a random time whose law we identify, and goes from the value 1 to a value that is a strictly decreasing and deterministic function of the time of the jump, related to the size of the largest component in Erd & odblac;s-R & eacute;nyi random graphs. After the jump, the total variation distance follows this function down to 0.