English

Non-integrality of some Steinberg modules

Algebraic Topology 2020-09-28 v2 Geometric Topology Number Theory

Abstract

We prove that the Steinberg module of the special linear group of a quadratic imaginary number ring which is not Euclidean is not generated by integral apartments. Assuming the generalized Riemann hypothesis, this shows that the Steinberg module of a number ring is generated by integral apartments if and only if the ring is Euclidean. We also construct new cohomology classes in the top dimensional cohomology group of the special linear group of some quadratic imaginary number rings.

Keywords

Cite

@article{arxiv.1810.07683,
  title  = {Non-integrality of some Steinberg modules},
  author = {Jeremy Miller and Peter Patzt and Jennifer C. H. Wilson and Dan Yasaki},
  journal= {arXiv preprint arXiv:1810.07683},
  year   = {2020}
}

Comments

17 pages. To appear in Journal of Topology

R2 v1 2026-06-23T04:43:34.392Z