Glasnik matematički, Vol. 39 No. 1, 2004.
Original scientific paper
A generalization of the 0-numerical range
Rajna Rajić
Abstract
Let H be a complex Hilbert space. Given a bounded linear operator A on H, we describe the set
Rn(A) = {V*AW : V,W : H, V*V = W*W = In, V*W = 0}.
It is shown that the closed matricial convex hull of Rn(A) is a closed ball of radius
min {|A - I| : }
centered at the origin.
Keywords
q-numerical range of an operator
Hrčak ID:
1270
URI
Publication date:
1.6.2004.
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