Topological centers of module actions induced by unitary representations

In this paper, we study the topological centers of bilinear maps induced by unitary representations, giving a characterization when the center is minimal and also conditions which guarantee that the center is maximal. Various examples whose topological centers are maximal, minimal or neither will be given. We will also investigate the topological centers of sub-representations, direct sums and tensor products. © 2010 Elsevier Inc. All rights reserved.