Integral representations of a certain twisted group ring
Let K be a global field, L a Galois extension of K of degree 2 with Galois group G, R a Dedekind domain with quotient field K, and S the integral closure of R in L. If \(\Lambda\) is the twisted group ring of G over S, the authors study the \(\Lambda\) lattices. An interesting explicit formula (which involves the class number of R) for the number of non- isomorphic indecomposable lattices is obtained by studying the related problem over local fields. Here, with R a complete discrete valuation ring with quotient field K, the authors give a complete list of the indecomposable \(\Lambda\) lattices.
number of non-isomorphic indecomposable lattices
scientific article; zbMATH DE number 4134247