On singular critical points of positive operators in Krein spaces

Citation
B. Curgus et al., On singular critical points of positive operators in Krein spaces, P AM MATH S, 128(9), 2000, pp. 2621-2626
Citations number
6
Categorie Soggetti
Mathematics
Journal title
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY
ISSN journal
00029939 → ACNP
Volume
128
Issue
9
Year of publication
2000
Pages
2621 - 2626
Database
ISI
SICI code
0002-9939(2000)128:9<2621:OSCPOP>2.0.ZU;2-0
Abstract
We give an example of a positive operator B in a Krein space with the follo wing properties: the nonzero spectrum of B consists of isolated simple eige nvalues, the norms of the orthogonal spectral projections in the Krein spac e onto the eigenspaces of B are uniformly bounded and the point infinity is a singular critical point of B.