Tokyo Probability Seminar

Seminar information archive ~04/19Next seminarFuture seminars 04/20~

Date, time & place Monday 16:00 - 17:30 126Room #126 (Graduate School of Math. Sci. Bldg.)
Organizer(s) Makiko Sasada, Shuta Nakajima

2015/11/30

16:50-18:20   Room #128 (Graduate School of Math. Sci. Bldg.)
Raoul Normand (Institute of Mathematics, Academia Sinica)
Self-organized criticality in a discrete model of limited aggregation
[ Abstract ]
We consider a discrete model of coagulation, where a large number of particles are initially given a prescribed number of arms. We successively choose arms uniformly at random and bind them two by two, unless they belong to "large" clusters. In that sense, the large clusters are frozen and become inactive. We study the graph structure obtained, and describe what a typical cluster looks like. We show that there is a fixed time T such that, before time T, a typical cluster is a subcritical Galton-Watson tree, whereas after time T, a typical cluster is a critical Galton-Watson tree. In that sense, we observe a phenomenon called self-organized criticality.