English

Geometric realizations of the $s$-weak order and its lattice quotients

Combinatorics 2025-12-08 v4

Abstract

For an nn-tuple ss of non-negative integers, the ss-weak order is a lattice structure on ss-trees, generalizing the weak order on permutations. We first describe the join irreducible elements, the canonical join representations, and the forcing order of the ss-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 ss-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