
arXiv: 1407.7507
In this article, we investigate the set of $\gamma$-sortable elements, associated with a Coxeter group $W$ and a Coxeter element $\gamma\in W$, under Bruhat order, and we denote this poset by $\mathcal{B}_{\gamma}$. We show that this poset belongs to the class of SB-lattices recently introduced by Hersh and Mészáros, by proving a more general statement, namely that all join-distributive lattices are SB-lattices. The observation that $\mathcal{B}_{\gamma}$ is join-distributive is due to Armstrong. Subsequently, we investigate for which finite Coxeter groups $W$ and which Coxeter elements $\gamma\in W$ the lattice $\mathcal{B}_{\gamma}$ is in fact distributive. It turns out that this is the case for the "coincidental" Coxeter groups, namely the groups $A_{n},B_{n},H_{3}$ and $I_{2}(k)$. We conclude this article with a conjectural characteriziation of the Coxeter elements $\gamma$ of said groups for which $\mathcal{B}_{\gamma}$ is distributive in terms of forbidden orientations of the Coxeter diagram.
join-distributive lattices, SB-labelings, sortable elements, Coxeter groups, Bruhat order, crosscut complexes, distributive lattices, Combinatorial aspects of groups and algebras, antimatroids, Combinatorics of partially ordered sets, Reflection and Coxeter groups (group-theoretic aspects), FOS: Mathematics, Other generalizations of distributive lattices, Mathematics - Combinatorics, Combinatorics (math.CO), Möbius functions, 20F55 (Primary), 06D75, 06A07 (Secondary)
join-distributive lattices, SB-labelings, sortable elements, Coxeter groups, Bruhat order, crosscut complexes, distributive lattices, Combinatorial aspects of groups and algebras, antimatroids, Combinatorics of partially ordered sets, Reflection and Coxeter groups (group-theoretic aspects), FOS: Mathematics, Other generalizations of distributive lattices, Mathematics - Combinatorics, Combinatorics (math.CO), Möbius functions, 20F55 (Primary), 06D75, 06A07 (Secondary)
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 2 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
