English

Locally uniform random permutations with large increasing subsequences

Probability 2024-12-19 v2 Combinatorics

Abstract

We investigate the maximal size of an increasing subset among points randomly sampled from certain probability densities. Kerov and Vershik's celebrated result states that the largest increasing subset among NN uniformly random points on [0,1]2[0,1]^2 has size asymptotically 2N2\sqrt{N}. More generally, the order Θ(N)\Theta(\sqrt{N}) still holds if the sampling density is continuous. In this paper we exhibit two sufficient conditions on the density to obtain a growth rate equivalent to any given power of NN greater than N\sqrt{N}, up to logarithmic factors. Our proofs use methods of slicing the unit square into appropriate grids, and investigating sampled points appearing in each box.

Keywords

Cite

@article{arxiv.2301.07658,
  title  = {Locally uniform random permutations with large increasing subsequences},
  author = {Victor Dubach},
  journal= {arXiv preprint arXiv:2301.07658},
  year   = {2024}
}

Comments

18 pages, 4 figures

R2 v1 2026-06-28T08:14:42.558Z