Lattice permutations and Poisson-Dirichlet distribution of cycle lengths
We study random spatial permutations on Z^3 where each jump x -> π(x) is penalized by a factor exp(-T ||x-π(x)||^2). The system is known to exhibit a phase transition for low enough T where macroscopic cycles appear. We observe that the lengths of such cycles are distributed according to Poisson-Dirichlet. This can be explained heuristically using a stochastic coagulation-fragmentation process for long cycles, which is supported by numerical data.
cond-mat.stat-mech↗