doubly commuting hyponormal \(n\)-tuples
Cartesian form of Putnam's inequality for doubly commuting hyponormal \(n\)-tuples
The authors give some Cartesian form of Putnam's inequality bounded by the area of the joint approximate point spectra for doubly commuting hyponormal \(n\)-tuples by using the inequality bounded by the area of the Xia spectra for semi-hyponormal \(n\)-tuples of operators given by Xia and give also some relation between the Taylor and Xia spectra of such \(n\)-tuples.
scientific article; zbMATH DE number 1633098