CONFORMAL TRANSFORMATIONS OF DISSIPATIVE OPERATORS
Bernard Aupetit, Driss Drissi · 1999
In the rst part of this paper we give an elementary proof of the Kreiss Theorem [6] and we slightly improve the Leveque{Trefethen{Spijker Theorem [8; 12] for the case of matrices. In the second part we use the previous results to prove that if T is a quasi-dissipative matrix, and if ’ is a conformal transformation of the negative half-plane onto the unit disk, then ’(T ) has bounded powers.