English

Order polytopes of crown posets

Combinatorics 2025-12-10 v3

Abstract

In the last decade, the order polytope of the zigzag poset has been thoroughly studied. A related poset, called \emph{crown poset}, obtained by adding an extra relation between the endpoints of an even zigzag poset, is not so well understood. In this paper, we study the order polytopes of crown posets. We provide explicit formulas for their ff-vectors. We provide recursive formulas for their Ehrhart polynomial, giving a counterpart to formulas found in the zigzag case by Petersen--Zhuang (2025). We use these formulas to simplify a computation by Ferroni--Morales--Panova (2025) of the linear term of the order polynomial of these posets. Furthermore, we provide a combinatorial interpretation for the coefficients of the hh^*-polynomial in terms of the cyclic swap statistic on cyclically alternating permutations, which provides a circular version of a result by Coons--Sullivant (2023).

Keywords

Cite

@article{arxiv.2504.05123,
  title  = {Order polytopes of crown posets},
  author = {Teemu Lundström and Leonardo Saud Maia Leite},
  journal= {arXiv preprint arXiv:2504.05123},
  year   = {2025}
}

Comments

25 pages, 9 figures. Typos were fixed, Example 5.20 was added, and notation was changed

R2 v1 2026-06-28T22:49:30.882Z