On $H$-simple not necessarily associative algebras

TL;DR

This paper explores generalized H-actions on finite dimensional algebras, establishing the existence of an exponent for the growth of polynomial identities, extending results to non-associative and graded algebras.

Contribution

It introduces a broad framework for H-actions on algebras, including non-associative and graded cases, and proves the existence of codimension growth exponents.

Findings

Existence of an exponent for polynomial H-identity growth in finite dimensional H-simple algebras.

Extension of codimension growth results to graded-simple and non-associative algebras.

Analysis of free-forgetful adjunctions for gradings and H-actions.

Abstract

An algebra A with a generalized H-action is a generalization of an H-module algebra where H is just an associative algebra with 1 and a relaxed compatibility condition between the multiplication in A and the H-action on A holds. At first glance this notion may appear too general, however it enables to work with algebras endowed with various kinds of additional structures (e.g. (co)module algebras over Hopf algebras, graded algebras, algebras with an action of a (semi)group by (anti)endomorphisms). This approach proves to be especially fruitful in the theory of polynomial identities. We show that if A is a finite dimensional (not necessarily associative) algebra over a field of characteristic 0 and A is simple with respect to a generalized H-action, then there exists an exponent of the codimension growth of polynomial H-identities of A. In particular, if A is a finite dimensional (not necessarily group graded) graded-simple algebra, then there exists an exponent of the codimension growth of graded polynomial identities of A. In addition, we study the free-forgetful adjunctions corresponding to (not necessarily group) gradings and generalized H-actions.