منابع مشابه
Operators with numerical range in a closed halfplane
Various characterizations are given of real and complex Hilbert space operators with the numerical range in a closed halfplane.
متن کاملOn Closed Operators with Closed Range1
It is well-known that if T is an everywhere defined bounded operator on a Banach space X to a Banach space Y and T* is its adjoint, then the range R(T*) of T* is closed in X* if and only if the range R(T) of T is closed in Y (cf. [2, pp. 487-489]). The object of this note is to establish this result for closed but possibly unbounded operators. This result, for the unbounded case, is of great ut...
متن کاملLinear operators of Banach spaces with range in Lipschitz algebras
In this paper, a complete description concerning linear operators of Banach spaces with range in Lipschitz algebras $lip_al(X)$ is provided. Necessary and sufficient conditions are established to ensure boundedness and (weak) compactness of these operators. Finally, a lower bound for the essential norm of such operators is obtained.
متن کاملIsometric and Closed-Range Composition Operators between Bloch-Type Spaces
We present an overview of the known results describing the isometric and closed-range composition operators on different types of holomorphic function spaces. We add new results and give a complete characterization of the isometric univalently induced composition operators acting between Bloch-type spaces. We also add few results on the closed-range determination of composition operators on Blo...
متن کاملThe Closed Range Property for Banach Space Operators
Let T be a bounded operator on a complex Banach space X. If V is an open subset of the complex plane, we give a condition sufficient for the mapping f(z) 7→ (T − z)f(z) to have closed range in the Fréchet space H(V, X) of analytic X-valued functions on V . Moreover, we show that there is a largest open set U for which the map f(z) 7→ (T − z)f(z) has closed range in H(V, X) for all V ⊆ U . Final...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Tohoku Mathematical Journal
سال: 1972
ISSN: 0040-8735
DOI: 10.2748/tmj/1178241589