Verbal wreath products and certain product varieties of groups

Actions, wreath products of C-varieties and concatenation product

The framework of C-varieties, introduced by the third author, extends the scope of Eilenberg’s variety theory to new classes of languages. In this paper, we first define C-varieties of actions, which are closely related to automata, and prove their equivalence with the original definition of C-varieties of stamps. Next, we complete the study of the wreath product initiated by Ésik and Ito by ex...

Two Problems on Varieties of Groups Generated by Wreath Products

Wreath Products and Existentially Complete Solvable Groups

It is known that the theory of abelian groups has a model companion but that the theory of groups does not. We show that for any fixed 22 a 2 the theory of groups solvable of length s 22 has no model companion. For the metabelian case (22 = 2) we prove the stronger result that the classes of finitely generic, infinitely generic, and existentially complete metabelian groups are all distinct. We ...

Automorphism Groups of Wreath Product Digraphs

We strengthen a classical result of Sabidussi giving a necessary and sufficient condition on two graphs, X and Y , for the automorphsim group of the wreath product of the graphs, Aut(X o Y ) to be the wreath product of the automorphism groups Aut(X) o Aut(Y ). We also generalize this to arrive at a similar condition on color digraphs. The main purpose of this paper is to revisit a well-known an...

Automorphisms of Regular Wreath Product p-Groups

We present a useful new characterization of the automorphisms of the regular wreath product group P of a finite cyclic p-group by a finite cyclic p-group, for any prime p, and we discuss an application. We also present a short new proof, based on representation theory, for determining the order of the automorphism group Aut P , where P is the regular wreath product of a finite cyclic p-group by...