London Algebra Colloquium abstract

Verbally prime algebras: tensor products and PI equivalence

Plamen Kochloukov (Campinas, Brazil), 20th May 2010

Abstract

The verbally prime ideals of identities of associative algebras play a prominent role in PI theory. These were described in concrete terms by Kemer, under the assumption of characteristic 0 base field. He also showed that the tensor product of any two verbally prime algebras satisfies the same polynomial identities as another verbally prime algebra. In this talk we shall discuss possible generalisations of this result to the case of positive characteristic. It turns out one may obtain new (and significantly simpler) proofs of the above mentioned result by means of graded polynomial identities. Such an approach has an advantage that it is (almost) characteristic-free. It will be shown that in positive characteristic one does not have the PI equivalences from the characteristic 0 case. Moreover we shall give a “measure” of the distance among the ideals of identities for the algebras involved, in terms of their Gelfand–Kirillov dimensions.