
Journal of Convex Analysis 18 (2011), No. 1, 059065 Copyright Heldermann Verlag 2011 A Representation of Ginvariant norms for Eaton Triple Piotr Niemiec Jagiellonian University, Institute of Mathematics, ul. Lojasiewicza 6, 30348 Kraków, Poland piotr.niemiec@uj.edu.pl TinYau Tam Dept. of Mathematics and Statistics, Auburn University, Auburn, AL 368495310, U.S.A. tamtiny@auburn.edu We obtain a representation of unitarily invariant norm in terms of Ky Fan norms [see R. Bhatia, Matrix Analysis, Springer, New York et al., 1997, p. 35]. Indeed we obtain a more general result in the context of Eaton triple with reduced triple. Examples are given. Keywords: Eaton triple, Ginvariant norms, symmetric gauge functions, Ky Fan norms, finite reflection groups. MSC: 15A60, 65F35 [ Fulltextpdf (107 KB)] for subscribers only. 