English

Cycles and sorting index for matchings and restricted permutations

Combinatorics 2012-06-07 v1

Abstract

We prove that the Mahonian-Stirling pairs of permutation statistics (\sor,\cyc)(\sor, \cyc) and (\inv,rlmin)(\inv, \mathrm{rlmin}) are equidistributed on the set of permutations that correspond to arrangements of nn non-atacking rooks on a Ferrers board with nn rows and nn columns. The proofs are combinatorial and use bijections between matchings and Dyck paths and a new statistic, sorting index for matchings, that we define. We also prove a refinement of this equidistribution result which describes the minimal elements in the permutation cycles and the right-to-left minimum letters. Moreover, we define a sorting index for bicolored matchings and use it to show analogous equidistribution results for restricted permutations of type BnB_n and DnD_n.

Keywords

Cite

@article{arxiv.1206.1301,
  title  = {Cycles and sorting index for matchings and restricted permutations},
  author = {Svetlana Poznanovik},
  journal= {arXiv preprint arXiv:1206.1301},
  year   = {2012}
}

Comments

23 pages

R2 v1 2026-06-21T21:15:15.270Z