In this paper we describe the automorphism groups of the endomorphism semigroups of free Burnside groups B(m, n) for odd exponents n ≥ 1003. We prove, that the groups Aut(End(B(m, n))) and Aut(B(m, n)) are canonically isomorphic. In particular, if the groups Aut(End(B(m, n))) and Aut(End(B(k, n))) are isomorphic, then m = k.
1The free Burnside group B(m, n) is the free group of rank m of the variety B n of all groups satisfying the identity x n = 1. The group B(m, n) is isomorphic to the quotient group of the absolutely free group F m of rank m by normal subgroup F n m generated by all n-th powers of its elements. It is well known (see [1, Theorem 2.15] that for all odd n ≥ 665 and rank m > 1 the group B(m, n) is infinite (and even has exponential growth). According to one other theorem of S.I.Adyan (see [1, Theorem 3.21]) for m > 1 and odd periods n ≥ 665 the center of B(m, n) is trivial and hence, B(m, n) is isomorphic to the inner automorphism subgroup Inn(B(m, n)) of the automorphism group Aut (B(m, n)). Other results on automorphisms and monomorphisms of the groups B(m, n) appeared relatively recently in [2]- [10]. In this paper we describe the automorphism groups of the endomorphism semigroups of B(m, n) for odd exponents n ≥ 1003. In particular, we prove, that the groups Aut(End(B(m, n))) and Aut(End(B(k, n))) are isomorphic if and only if m = k. This is a particular problem about End(A), for A a free algebra in a certain variety, was raised by B.I.Plotkin in [14]. Analogous problems for End(F ) with F a finitely generated free group or free monoid were solved by Formanek in [12] and Mashevitzky and Schein in [13] respectively.