English

Hopping from Chebyshev polynomials to permutation statistics

Combinatorics 2019-08-23 v3

Abstract

We prove various formulas which express exponential generating functions counting permutations by the peak number, valley number, double ascent number, and double descent number statistics in terms of the exponential generating function for Chebyshev polynomials, as well as cyclic analogues of these formulas for derangements. We give several applications of these results, including formulas for the (1)(-1)-evaluation of some of these distributions. Our proofs are combinatorial and involve the use of monomino-domino tilings, the modified Foata-Strehl action (a.k.a. valley-hopping), and a cyclic analogue of this action due to Sun and Wang.

Cite

@article{arxiv.1812.10601,
  title  = {Hopping from Chebyshev polynomials to permutation statistics},
  author = {Jordan O. Tirrell and Yan Zhuang},
  journal= {arXiv preprint arXiv:1812.10601},
  year   = {2019}
}

Comments

16 pages

R2 v1 2026-06-23T06:56:59.202Z