Canad. J. Math. 57(2005), 61-81
Printed: Feb 2005
Decompositions of spectral type are
obtained for closed Hilbert space operators with empty resolvent
set, but whose square has closure which is spectral. Krein space
situations are also discussed.
unbounded operators, closed operators, spectral resolution, indefinite metric
47A05 - General (adjoints, conjugates, products, inverses, domains, ranges, etc.)
47A15 - Invariant subspaces [See also 47A46]
47B40 - Spectral operators, decomposable operators, well-bounded operators, etc.
47B50 - Operators on spaces with an indefinite metric [See also 46C50]
46C20 - Spaces with indefinite inner product (Kreiin spaces, Pontryagin spaces, etc.) [See also 47B50]