Peer-reviewedCC BY 4.0The Electronic Journal of Combinatorics
On a q-Analogue of the Zeta Polynomial of Posets
Abstract
We introduce a q-analogue of the classical Zeta polynomial of fiinite partially ordered sets, as a polynomial in one variable x with coefficients depending on the indeterminate q. We prove some properties of this polynomial invariant, including its behaviour with respect to duality, product and disjoint union. The leading term is a q-analogue of the number of maximal chains, but not always with non-negative coefficients. The value at q=0 turns out to be essentially the characteristic polynomial.
Related
BibTeX
@article{chapoton2026qanalogue,
title = {{On a $q$-Analogue of the Zeta Polynomial of Posets}},
author = {Frédéric Chapoton},
journal = {The Electronic Journal of Combinatorics},
year = {2026},
month = oct,
doi = {10.37236/13820},
url = {https://www.combinatorics.org/ojs/index.php/eljc/article/view/v33i4p21},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - On a q-Analogue of the Zeta Polynomial of Posets
AU - Frédéric Chapoton
PY - 2026
DA - 2026/10/23
JO - The Electronic Journal of Combinatorics
DO - 10.37236/13820
UR - https://www.combinatorics.org/ojs/index.php/eljc/article/view/v33i4p21
AB - We introduce a q-analogue of the classical Zeta polynomial of fiinite partially ordered sets, as a polynomial in one variable x with coefficients depending on the indeterminate q. We prove some properties of this polynomial invariant, including its behaviour with respect to duality, product and disjoint union. The leading term is a q-analogue of the number of maximal chains, but not always with non-negative coefficients. The value at q=0 turns out to be essentially the characteristic polynomial.
SN - 1077-8926
ER -