ISOMETRIES OF THE TRACE CLASS
BERNARD RUSSO1
Let 3 denote the Banach space of trace class operators on a com- plex Hilbert space H, in the norm ||P||i=Tr(| P|). The space 3 is a two-sided ideal in the algebra £ of all bounded operators on H. See [4]. Theorem. // References 1. J. Dixmier, Les algebres d'operateurs dans I'espace hilbertien, Gauthier-Villars, Paris, 1957. 2. R. V. Kadison, Isometries of operator algebras, Ann. of Math. (2) 54 (1951), 325-338. 3. B. Russo, Isometries of L" spaces associated with finite von Neumann algebras, Bull. Amer. Math. Soc. 74 (1968),228-232. 4. R. Schatten, Norm ideals of completely continuous operators, Springer-Verlag, Berlin, 1960. University of California, Irvine Received by the editors March 7, 1969. 1 This research was supported by the National Science Foundation Grant GP- 8291. 213 License or copyright restrictions may apply to redistribution; see https://www.ams.org/journal-terms-of-use