PreprintCC BY 4.0arXiv
Real-rooted Ehrhart h*-polynomials of crown posets and wheel and whirl matroids
Abstract
We prove that the Ehrhart h*-polynomials of crown order polytopes are real-rooted, settling a conjecture of Lundström and Saud Maia Leite. For each integer r≥3, the crown order polytope on 2r elements and the rank-r whirl base polytope have the same h*-polynomial. The h*-polynomials of the rank-r wheel and whirl base polytopes, as well as every convex combination of the two, have 2r−2 distinct negative roots. Their coefficient sequences are positive, unimodal, and strictly ultra log-concave of order 2r−2.
Related
BibTeX
@misc{cao2026realrooted,
title = {{Real-rooted Ehrhart $h^*$-polynomials of crown posets and wheel and whirl matroids}},
author = {Ying Cao and Houshan Fu},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.40496},
eprint = {2610.40496},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.40496},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Real-rooted Ehrhart h^*-polynomials of crown posets and wheel and whirl matroids
AU - Ying Cao
AU - Houshan Fu
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.40496
UR - https://arxiv.org/abs/2610.40496
AB - We prove that the Ehrhart h^*-polynomials of crown order polytopes are real-rooted, settling a conjecture of Lundström and Saud Maia Leite. For each integer r≥3, the crown order polytope on 2r elements and the rank-r whirl base polytope have the same h^*-polynomial. The h^*-polynomials of the rank-r wheel and whirl base polytopes, as well as every convex combination of the two, have 2r−2 distinct negative roots. Their coefficient sequences are positive, unimodal, and strictly ultra log-concave of order 2r−2.
ER -