ACTA issues

Inequalities for some positive functionals on operator algebras

Ciprian Foias, Sami M. Hamid, Constantin Onica, Carl Pearcy

Acta Sci. Math. (Szeged) 74:1-2(2008), 239-244

Abstract. In this note we first make a modest improvement of an inequality of Brown--Lomonosov--Simonic on certain transitive operator algebras. Then we use a result of Foias--Pasnicu--Voiculescu to provide similar inequalities for algebras generated by a quasitriangular operator.

AMS Subject Classification (1991): 47A15

Keyword(s): Invariant subspace, hyperinvariant subspace, quasitriangular, transitive operator

Received January 3, 2008, and in revised form February 11, 2008. (Registered under 6014/2009.)