1. Propriétés spectrales des restrictions d’opérateurs de la classe $A$ Creator: Benhida, Chafiq Format: bez média and svazek Type: model:article and TEXT Subject: math and restrictions of the class $A$ Language: English Description: We discuss here the question whether there exists an invariant subspace M for a contraction T in the class $A$ such that the spectrum of the restriction of T on M is the whole closed unit disc. Rights: http://creativecommons.org/publicdomain/mark/1.0/ and policy:public