Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5772972 | Linear Algebra and its Applications | 2017 | 10 Pages |
Abstract
Let H be a complex Hilbert space and let B(H) be the set of all bounded linear operators on H. For every AâB(H), the numerical range of A is the set W(A)={ãAx,xã:xâHandâxâ=1} and the diameter of W(A) is the number d(W(A))=supâ¡{|λâμ|:λ,μâW(A)}. A mapping T:B(H)âB(H) is called a diameter preserver if d(W(T(A)))=d(W(A)) for all AâB(H). In this article we give a characterization of surjective linear diameter preservers.
Related Topics
Physical Sciences and Engineering
Mathematics
Algebra and Number Theory
Authors
Jor-Ting Chan, Kong Chan,