In this note we characterize all the linear operators on the linear space of n × n complex matrices which preserve the numerical radius and all the linear operators on the real linear space of n × n ...

We prove the following statements about bounded linear operators on a separable, complex Hilbert space: (1) Every normal operator $N$ that is similar to a Hilbert ...

Measure and Integral, Banach and Hilbert Space, Linear Integral Equations. By Prof. Adriaan Cornelis Zaanen. (Bibliotheca Mathematica: a Series of Monographs on Pure ...