On a non-abelian Balog-Szemeredi-type lemma

Abstract

We show that if G is a group and A is a finite subset of G with |A^2| < K|A|, then for all k there is a symmetric neighbourhood of the identity S with S^k a subset of A^2A^{-2} and |S| > exp(-K^{O(k)})|A|.

5 pp. Corrected typos. Minor revisions