THE CAUCHY DUAL AND 2-ISOMETRIC LIFTINGS OF CONCAVE OPERATORS

Catalin Badea (1, 2) , Laurian Suciu

1 Université de Lille
2 LPP - Laboratoire Paul Painlevé - UMR 8524

We present some 2-isometric lifting and extension results for Hilbert space concave operators. For a special class of concave operators we study their Cauchy dual operators and discuss conditions under which these operators are subnormal. In particular, the quasinormality of compressions of such operators is studied.

Mots clés: Cauchy dual operator; 2-isometric liftings; concave operator; A-contraction; subnormal operator

Domaines: Analyse fonctionnelle [math.FA]

Catalin Badea, Laurian Suciu. THE CAUCHY DUAL AND 2-ISOMETRIC LIFTINGS OF CONCAVE OPERATORS. Journal of Mathematical Analysis and Applications, 2019. ⟨hal-03494647⟩