Spectral inclusion for subnormal -tuples
Author: Mihai Putinar
Journal: Proc. Amer. Math. Soc. 90 (1984), 405-406
MSC: Primary 47B20; Secondary 47A10
MathSciNet review: 728357
Abstract: Let be a subnormal operator on a Hilbert space and let be its minimal extension. Then a celebrated theorem due to P. Halmos asserts that , denoting by the spectrum. This note contains a multidimensional version, with respect to Taylor's joint spectrum, of this spectral inclusion theorem.
Keywords: Subnormal operator, commuting -tuple, Taylor's joint spectrum, minimal normal extension
Article copyright: © Copyright 1984 American Mathematical Society