Schur rings over a product of Galois rings

Sergei Evdokimov1, Ilia Ponomarenko1
1St.Petersburg Department of Steklov Mathematical Institute RAS, St. Petersburg, Russia

Tóm tắt

The recently developed theory of Schur rings over a finite cyclic group is generalized to Schur rings over a ring $$R$$ being a product of Galois rings of coprime characteristics. It is proved that if the characteristic of $$R$$ is odd, then as in the cyclic group case any pure Schur ring over $$R$$ is the tensor product of a pure cyclotomic ring and Schur rings of rank  $$2$$ over non-fields. Moreover, it is shown that in contrast to the cyclic group case there are non-pure Schur rings over $$R$$ that are not generalized wreath products.

Tài liệu tham khảo

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