Parabolic Tamari Lattices in Linear Type B

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Wenjie Fang - , École des Ponts ParisTech (Author)
  • Henri Mühle - , Institute of Algebra (Author)
  • Jean Christophe Novelli - , École des Ponts ParisTech (Author)

Abstract

We study parabolic aligned elements associated with the type-B Coxeter group and the so-called linear Coxeter element. These elements were introduced algebraically in (Mühle andWilliams, 2019) for parabolic quotients of finite Coxeter groups and were characterized by a certain forcing condition on inversions. We focus on the type-B case and give a combinatorial model for these elements in terms of pattern avoidance. Moreover, we describe an equivalence relation on parabolic quotients of the type-B Coxeter group whose equivalence classes are indexed by the aligned elements. We prove that this equivalence relation extends to a congruence relation for the weak order. The resulting quotient lattice is the type-B analogue of the parabolic Tamari lattice introduced for type A in (Mühle and Williams, 2019). These lattices have not appeared in the literature before.

Details

Original languageEnglish
Article number62
Number of pages12
JournalSéminaire Lotharingien de Combinatoire : SLC
Volume2022
Issue number86B
Publication statusPublished - 1 Apr 2022
Peer-reviewedYes

Keywords

Keywords

  • Coxeter–Catalan combinatorics, hyperoctahedral group, parabolic quotient, sign-symmetric permutation, Tamari lattice

Library keywords