Probability & Statistics Seminar

Boundary Behaviors at ∞ for Fragments in Simple Exchangeable Fragmentation-Coalescence Process

  • 演讲者:Xiaowen Zhou(康考迪亚大学)

  • 时间:2021-07-05 09:00-10:00

  • 地点:腾讯会议 ID 841890547

Abstract

    Exchangeable fragmentation-coagulation (EFC) processes are partition-valued stochastic processes first introduced by Berestycki. In this talk we consider the EFC processes for which the coagulations are multiple and not simultaneous, as in a A-coalescent, and the fragmentations dislocate at finite rate an individual block into sub-blocks of infinite size. Sufficient conditions are found for the block counting process to explode (i.e., to reach ∞) or not and for ∞ to be either an exit boundary or an entrance boundary. In a case of regularly varying fragmentation and coagulation mechanisms, we find regimes where the boundary ∞ can be either an exit, an entrance or a regular boundary.

    This talk is based on joint work with Clement Foucart.