Pairs of normal matrices with property L

Abstract

A short proof is given , under weaker ass ump tions, of t he foll owi ng theore m firs t proverl by K. Wiegman n: If t he e igenvalu es a i, /3i of t wo normal n X n matrices A, B may be nUIllbered in s uch a wa .v that t he eigen values I' i(Z) of C ( z )= a +zb are given by I'i(Z) = I' i+ Z/3 i (fo r i =