English

Refined inversion statistics on permutations

Combinatorics 2012-01-13 v2

Abstract

We introduce and study new refinements of inversion statistics for permutations, such as k-step inversions, (the number of inversions with fixed position differences) and non-inversion sums (the sum of the differences of positions of the non-inversions of a permutation). We also provide a distribution function for non-inversion sums, a distribution function for k-step inversions that relates to the Eulerian polynomials, and special cases of distribution functions for other statistics we introduce, such as (\leqk)-step inversions and (k1,k2)-step inversions (that fix the value separation as well as the position). We connect our refinements to other work, such as inversion tops that are 0 modulo a fixed integer d, left boundary sums of paths, and marked meshed patterns. Finally, we use non-inversion sums to show that for every number n > 34, there is a permutation such that the dot product of that permutation and the identity permutation (of the same length) is n.

Keywords

Cite

@article{arxiv.1106.1995,
  title  = {Refined inversion statistics on permutations},
  author = {Joshua Sack and Henning Úlfarsson},
  journal= {arXiv preprint arXiv:1106.1995},
  year   = {2012}
}

Comments

27 pages, 3 figures, 6 tables

R2 v1 2026-06-21T18:20:25.212Z