The numerical range and numerical radius of derivation operator δA and generalized derivation operator δA,B

Hacene Mecheri

Hacene Mecheri MATHEMAtics DEPARTMENT, COLLEGE of SCIENCE, Jouf UNIVERSITY, P.O. Box: 2014, SAKAKA, SAUDI ARABIA.

Keywords: Derivation Operator, Generalized Derivation, numerical radius.

Abstract

Abstract. Let H be a Hilbert space equipped with the inner product (,) andA, B, X, Z ∈ H.In this work we study a Now estimates for the numerical radius of the Derivation Operator δA and Generalized Derivation Operator δA,B and the product ZδA, ZδA,B are given, all operators are bounded linear on a complex Hilbert space L(H) .

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