The numerical range of non-negative operators in Krein spaces

We define and characterize the Krein space numerical range W(A) and the Krein space co-numerical range Wco(A) of a non-negative operator A in a Krein space. It is shown that the non-zero spectrum of A is contained in the closure of W(A) Wco(A).


Citation style:
Could not load citation form.


Use and reproduction:
All rights reserved