Title
Braid moves in commutation classes of the symmetric group
Abstract
We prove that the expected number of braid moves in the commutation class of the reduced word (s1s2sn1)(s1s2sn2)(s1s2)(s1) for the long element in the symmetric group Sn is one. This is a variant of a similar result by V.Reiner, who proved that the expected number of braid moves in a random reduced word for the long element is one. The proof is bijective and uses X.Viennots theory of heaps and variants of the promotion operator. In addition, we provide a refinement of this result on orbits under the action of even and odd promotion operators. This gives an example of a homomesy for a nonabelian (dihedral) group that is not induced by an abelian subgroup. Our techniques extend to more general posets and to other statistics.
Year
DOI
Venue
2017
10.1016/j.ejc.2016.10.008
Eur. J. Comb.
Field
DocType
Volume
Braid theory,Discrete mathematics,Abelian group,Combinatorics,Braid,Bijection,Symmetric group,Expected value,Operator (computer programming),Braid group,Mathematics
Journal
62
Issue
ISSN
Citations 
C
0195-6698
1
PageRank 
References 
Authors
0.38
9
4
Name
Order
Citations
PageRank
Anne Schilling1176.74
Nicolas M. Thiéry2124.66
graham white310.38
nathan williams411.06