English

On Excess in Finite Coxeter Groups

Group Theory 2014-05-13 v1

Abstract

For a finite Coxeter group WW and ww an element of WW the `excess' of ww is defined to be e(w)=min{(x)+(y)(w)    w=xy,  x2=y2=1}e(w) = \min\{\ell(x) + \ell(y) - \ell(w) \; | \; w=xy, \; x^2 = y^2 = 1\} where \ell is the length function on WW. Here we investigate the behaviour of e(w)e(w), and a related concept reflection excess, when restricted to standard parabolic subgroups of WW. Also the set of involutions inverting ww is studied.

Keywords

Cite

@article{arxiv.1405.2701,
  title  = {On Excess in Finite Coxeter Groups},
  author = {Sarah B. Hart and Peter J. Rowley},
  journal= {arXiv preprint arXiv:1405.2701},
  year   = {2014}
}

Comments

This is a preprint version. It has been accepted, subject to revision, in J. Pure Appl. Alg

R2 v1 2026-06-22T04:11:39.185Z