Conjecture on the longest increasing subsequence of conjugation-invariant permutations

From papers

Let (τn)n(\tau_n)_n be a sequence of conjugation-invariant random permutations, where τn\tau_n has size nn and random cycle type t(n)t^{(n)}. Suppose that

t1(n)/n0t_1^{(n)}/\sqrt{n}\longrightarrow0

in probability. Conjecture on the longest increasing subsequence. Then

1nLIS(τn)n2\frac{1}{\sqrt{n}}\operatorname{LIS}(\tau_n)\underset{n\to\infty}{\longrightarrow}2

in probability. The result would identify the same first-order asymptotic as for uniform permutations when the number of fixed points is negligible compared with n\sqrt n; related cases are known for random involutions and under additional cycle constraints.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Victor Dubach, “A geometric approach to conjugation-invariant random permutations”, arXiv:2402.10116 (2025).

Solutions 0

No solutions have been posted yet.