Bowen--Franks groups and minus class groups of cyclotomic number fields with prime conductor
Number Theory
2026-05-05 v1 Combinatorics
Abstract
Let be an odd rational prime and consider the cyclotomic number field of conductor . We construct a directed graph on vertices for which the torsion part of the corresponding Bowen--Franks group is closely related to the minus part of the class group of . In particular, both groups have the same cardinality up to an explicit power of . Furthermore, they are both -modules, and we prove the equality of the cardinalities of their isotypic components after tensoring them with the valuation ring of an appropriate -adic field for .
Cite
@article{arxiv.2605.01398,
title = {Bowen--Franks groups and minus class groups of cyclotomic number fields with prime conductor},
author = {Antonio Lei and Katharina Müller and Daniel Vallières},
journal= {arXiv preprint arXiv:2605.01398},
year = {2026}
}