Geometric realizations of the $s$-weak order and its lattice quotients
Combinatorics
2025-12-08 v4
Abstract
For an -tuple of non-negative integers, the -weak order is a lattice structure on -trees, generalizing the weak order on permutations. We first describe the join irreducible elements, the canonical join representations, and the forcing order of the -weak order in terms of combinatorial objects, generalizing the arcs, the non-crossing arc diagrams, and the subarc order for the weak order. We then extend the theory of shards and shard polytopes to construct geometric realizations of the -weak order and all its lattice quotients as polyhedral complexes, generalizing the quotient fans and quotientopes of the weak order.
Keywords
Cite
@article{arxiv.2405.02092,
title = {Geometric realizations of the $s$-weak order and its lattice quotients},
author = {Eva Philippe and Vincent Pilaud},
journal= {arXiv preprint arXiv:2405.02092},
year = {2025}
}
Comments
50 pages, 33 figures. Version 4: minor corrections, published version