English

Weak crossed-product orders over valuation rings

Rings and Algebras 2014-06-30 v1

Abstract

Let FF be a field, let VV be a valuation ring of FF of arbitrary Krull dimension (rank), let KK be a finite Galois extension of FF with group GG, and let SS be the integral closure of VV in KK. Let f:G×GK{0}f:G\times G\mapsto K\setminus \{0\} be a normalized two-cocycle such that f(G×G)S{0}f(G\times G)\subseteq S\setminus \{0\}, but we do not require that ff should take values in the group of multiplicative units of SS. One can construct a crossed-product VV-order Af=σGSxσA_f=\sum_{\sigma\in G}Sx_{\sigma} with multiplication given by xσsxτ=σ(s)f(σ,τ)xστx_{\sigma}sx_{\tau}=\sigma(s)f(\sigma,\tau)x_{\sigma\tau} for sSs\in S, σ,τG\sigma,\tau\in G. We characterize semihereditary and Dubrovin crossed-product orders, under mild valuation-theoretic assumptions placed on the nature of the extension K/FK/F.

Keywords

Cite

@article{arxiv.1406.7065,
  title  = {Weak crossed-product orders over valuation rings},
  author = {John S. Kauta},
  journal= {arXiv preprint arXiv:1406.7065},
  year   = {2014}
}
R2 v1 2026-06-22T04:48:45.540Z