Quasi-sectorial contractions

Valentin A. Zagrebnov (1, 2)

1 CPT - Centre de Physique Théorique - UMR 6207
2 CPT - Centre de Physique Théorique - UMR 7332

We revise the notion of the quasi-sectorial contractions. Our main theorem establishes a relation between semigroups of quasi-sectorial contractions and a class of m-sectorial generators. We discuss a relevance of this kind of contractions to the theory of operator-norm approximations of strongly continuous semigroups.

Mots clés: Operator numerical range; m-Sectorial generators; Contraction semigroups; Quasi-sectorial contractions; Holomorphic semigroups; Semigroup operator-norm approximations

Domaines: Analyse fonctionnelle [math.FA]

Valentin A. Zagrebnov. Quasi-sectorial contractions. Journal of Functional Analysis, 2008, 254 (9), pp.2503-2511. ⟨10.1016/j.jfa.2007.10.010⟩. ⟨hal-00184941⟩