Asymptotic independence of descent sets and being an n-cycle

For each nn, let [n1]={1,,n1}[n-1]=\{1,\ldots,n-1\}, and let βn(I)\beta_n(I) denote the number of permutations in SnS_n with descent set I[n1]I\subseteq[n-1], while βncyc(I)\beta^{\mathrm{cyc}}_n(I) denotes the number of nn-cycles with descent set II. Asymptotic independence conjecture.

limnmaxI[n1]nβncyc(I)βn(I)1=0.\lim_{n\to\infty}\max_{\varnothing \subsetneqq I \subsetneqq [n-1]} \left| \frac{n\, \beta^{\mathrm{cyc}}_n(I)}{\beta_n(I)} - 1\right| = 0.

This asserts that, uniformly over all non-empty proper descent sets, having descent set II and being an nn-cycle are asymptotically independent, with the proportion of nn-cycles tending to 1/n1/n as it does among all permutations. The source presents this as a conjectural strengthening of the known asymptotic independence result for alternating permutations.

Sources & referencesView supporting material

Primary source

Sergi Elizalde and Justin M. Troyka, “Exact and asymptotic enumeration of cyclic permutations according to descent set”, arXiv:1710.05103 (2019).

Progress summary

Never refreshed

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

Solutions 0

No solutions have been posted yet.