Maximal common divisors in monoid algebras
Abstract
A commutative cancellative monoid has the MCD property if every nonempty finite subset has a maximal common divisor, and it has the MCD-finite property if every such subset has only finitely many maximal common divisors up to associates. We study these properties in monoid algebras. We first identify atomic and antimatter families of rank-$1$ torsion-free MCD monoids. We then prove that, for a field F and a torsion-free monoid M, the MCD property ascends from M to F[M] whenever the group algebra F[π’(M)] satisfies the ascending chain condition on principal ideals (π’(M) denotes the Grothendieck group of M). We also record the pre-Schreier case as a consequence of classical GCD ascent. In contrast, for every prime p, we construct a reduced rank-$3$ MCD monoid M such that π½p[M] is not an MCD domain, and an atomic rank-$1$ MCD monoid whose algebra over π½p is not atomic. We further prove that the prime reciprocal monoids considered here are MCD-finite and that MCD-finiteness ascends to polynomial extensions. Finally, for every prime p, we construct a rank-$1$ torsion-free q-GCD monoid whose algebra over π½p is not q-GCD, where the q-GCD property requires at most one maximal common divisor up to associates for every nonempty finite subset.
Related
- Binomial Artin-Schelter Regular Algebras and Twisted Monoid Algebras
- (a,a)-Carmichael numbers and greatest common divisors of pβa
- Properties of the π±-Monoid of Weighted Leavitt Path Algebras
- Orthogonality graphs of real Cayley-Dickson algebras. Part I: Doubly alternative zero divisors and their hexagons
- Zero divisors in group algebras of torsion-free groups in odd characteristic
BibTeX
@misc{blitz2026maximal,
title = {{Maximal common divisors in monoid algebras}},
author = {Grant Blitz and Felix Gotti and Darren Han and Hengrui Liang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.18947},
eprint = {2609.18947},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.18947},
}
RIS
TY - UNPB
TI - Maximal common divisors in monoid algebras
AU - Grant Blitz
AU - Felix Gotti
AU - Darren Han
AU - Hengrui Liang
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2609.18947
UR - https://arxiv.org/abs/2609.18947
AB - A commutative cancellative monoid has the MCD property if every nonempty finite subset has a maximal common divisor, and it has the MCD-finite property if every such subset has only finitely many maximal common divisors up to associates. We study these properties in monoid algebras. We first identify atomic and antimatter families of rank-$1$ torsion-free MCD monoids. We then prove that, for a field F and a torsion-free monoid M, the MCD property ascends from M to F[M] whenever the group algebra F[π’(M)] satisfies the ascending chain condition on principal ideals (π’(M) denotes the Grothendieck group of M). We also record the pre-Schreier case as a consequence of classical GCD ascent. In contrast, for every prime p, we construct a reduced rank-$3$ MCD monoid M such that π½_p[M] is not an MCD domain, and an atomic rank-$1$ MCD monoid whose algebra over π½_p is not atomic. We further prove that the prime reciprocal monoids considered here are MCD-finite and that MCD-finiteness ascends to polynomial extensions. Finally, for every prime p, we construct a rank-$1$ torsion-free q-GCD monoid whose algebra over π½_p is not q-GCD, where the q-GCD property requires at most one maximal common divisor up to associates for every nonempty finite subset.
ER -