Abstract
In this note we give necessary and sufficient conditions for a holomorphic operator valued function to coincide weakly with the characteristic function of a bounded operator on a Krein space. We also present a sufficient condition such that the weak isomorphism is an isomorphism, i.e., is bounded.
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Dedicated to Israel Gohberg on the occasion of his sixtieth birthday
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© 1989 Birkhäuser Verlag Basel
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Ćurgus, B., Dijksma, A., Langer, H., de Snoo, H.S.V. (1989). Characteristic Functions of Unitary Colligations and of Bounded Operators in Krein Spaces. In: Dym, H., Goldberg, S., Kaashoek, M.A., Lancaster, P. (eds) The Gohberg Anniversary Collection. Operator Theory: Advances and Applications, vol 40/41. Birkhäuser, Basel. https://doi.org/10.1007/978-3-0348-9144-8_26
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DOI: https://doi.org/10.1007/978-3-0348-9144-8_26
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