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 ...

In this work, the notion of extended eigenvalues of a 2 × 2 lower triangular operator matrix has been researched. More precisely, the relations between the extended spectrum of a 2 × 2 lower ...

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