Longest increasing subsequences of dyadic-type chaotic orbits

Abstract

This paper studies the longest increasing subsequence (LIS) problem for sequences generated by dyadic-type chaotic interval maps. Starting from a single point $x\in[0,1)$ chosen uniformly at random, we form the order pattern of the first $N$ points of its orbit, with the doubling map as the basic model. Let $λ_1^{(N)}$ be the LIS length, equivalently the length of the first row of the Young diagram obtained by Schensted's insertion. We show that $\mathbb E[λ_1^{(N)}]/\sqrt N\to 2$, matching the leading asymptotics in the classical Ulam--Hammersley problem for uniform random permutations.