Operator Holes and Extensions of Sectorial Operators and Dual Pairs of Contractions
نویسنده
چکیده
A description of the set of m-sectorial extensions of a dual pair {A1, A2} of nonnegative operators is obtained. Some classes of nonaccretive extensions of the dual pair {A1, A2} are described too. Both problems are reduced to similar problems for a dual pair {T1, T2} of nondensely defined symmetric contractions Tj = (I−Aj)(I+Aj), j ∈ {1, 2}. In turn these problems are reduced to the investigation of the corresponding operator ”holes”. A complete description of the set of all proper and improper extensions of a nonnegative operator is obtained too.
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تاریخ انتشار 2005