English

The sorting index

Combinatorics 2010-10-25 v2

Abstract

We consider a bivariate polynomial that generalizes both the length and reflection length generating functions in a finite Coxeter group. In seeking a combinatorial description of the coefficients, we are led to the study of a new Mahonian statistic, which we call the sorting index. The sorting index of a permutation and its type B and type D analogues have natural combinatorial descriptions which we describe in detail.

Keywords

Cite

@article{arxiv.1007.1207,
  title  = {The sorting index},
  author = {T. Kyle Petersen},
  journal= {arXiv preprint arXiv:1007.1207},
  year   = {2010}
}

Comments

14 pages, minor changes, new references added

R2 v1 2026-06-21T15:45:38.953Z