A group G is called unitarizable, if every uniformly bounded representation π:G→B(H) of G on a Hilbert space H is unitarizable. N. Monod and N. Ozawa in [6] prove that free Burnside groups B(m,n) are non unitarizable for arbitrary composite odd number n=n1n2 , where n1≥665 . We prove that for the same n the groups B(4,n) have continuum many non-isomorphic factor-groups, each one of which is non-unitarizable and uniformly non-amenable.
DOI: 10.46991/PYSUA.2010.44.3.040 Physical and Mathematical Sciences, 45(1 (224) 40-43
