Abstract
Let w(x, y) be a word in two variables and π the variety determined by w. In this paper we raise the following question: if for every pair of elements a, b in a group G there exists g β G such that w(a g , b) = 1, under what conditions does the group G belong to π? In particular, we consider the n-Engel word w(x, y) = [x, n y]. We show that in this case the property is satisfied when the group G is metabelian. If n = 2, then we extend this result to the class of all solvable groups.
Notes
Communicated by A. Olshanskii.