Seminário Análise Funcional e Aplicações 

13/02/2009, 15:00 — 16:00 — Sala P3.10, Pavilhão de Matemática
Chafiq Benhida, Université de Lille 1, France

Hyponormality and subscalarity

Starting from M. Putinar's result showing that a hyponormal operator has a scalar extension which means that it is similar to the restriction to an invariant subspace of a (generalized) scalar operator (in the sense of Colojoara-Foias), we discuss this notion and show that backward Aluthge iterates of hyponormal operators are subscalar.