1. Numerical range of operators acting on Banach spaces
- Creator:
- Jahedi, Khadijeh and Yousefi, Bahmann
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- numerical range, weighted Hardy space, compact operator, and composition operator
- Language:
- English
- Description:
- The aim of the paper is to propose a definition of numerical range of an operator on reflexive Banach spaces. Under this definition the numerical range will possess the basic properties of a canonical numerical range. We will determine necessary and sufficient conditions under which the numerical range of a composition operator on a weighted Hardy space is closed. We will also give some necessary conditions to show that when the closure of the numerical range of a composition operator on a small weighted Hardy space has zero.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public