New aspects of Krein`s extension theory

• Published in: Український математичний журнал
• Date: 1994
• Main Authors: Brasche, J.F., Koshmanenko, V., Neidhardt, H.
• Format: Article
• Language: English
• Published: Інститут математики НАН України 1994
• Subjects: Статті
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/152533
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: New aspects of Krein`s extension theory / J.F. Brasche, V. Koshmanenko, H. Neidhardt // Український математичний журнал. — 1994. — Т. 46, № 1-2. — С. 37–54. — Бібліогр.: 45 назв. — англ.

The extension problem for closed symmetric operators with a gap is studied. A new kind of parametrization of extensions (the so-called Krein model) is developed. The notion of a singular operator plays the key role in our approach. We give the explicit description of extensions and establish the spe...