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Weighted shifts and commuting normal extension

Published online by Cambridge University Press:  09 April 2009

Arthur Lubin
Affiliation:
Mathematics DepartmentIllinois Institute of TechnologyChicago, Illinois 60616, U.S.A.
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Abstract

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The main result of this paper shows that the existence of commuting normal extension (c.n.e.) for an arbitrary family of commuting subnormal operators can be determined by considering appropriate families of multivariable weighted shifts. In proving this some known criteria for c.n.e. are generalized. It is also shown that a family of jointly quasi-normal operators has c.n.e.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1979

References

Abrahamse, M. B. (1978), ‘Commuting subnormal operators’, Ill. J. Math. 22, 171176.Google Scholar
Bram, J. (1955), ‘Subnormal operators’, Duke Math J. 22, 7594.Google Scholar
Embry, M. (1973), ‘A generalization of the Halmos-Bram criterion for subnormality’, Acta Sci. Math. (Szeged) 35, 6164.Google Scholar
Ito, T. (1958), ‘On the commutative family of subnormal operator's, J. Fac. Sci. Hokkaido Univ. 14, 115.Google Scholar
Jewell, N. P. and Lubin, A. (1979), ‘Commuting weighted shifts in several variables’ (to appear).Google Scholar
Lambert, A. (1976), ‘Subnormality and weighted shifts’, J. London Math. Soc. 14, 476480.Google Scholar
Lubin, A. (1976), ‘Models for commuting contractions’, Mich. Math. J. 23, 161165.Google Scholar
Lubin, A. (1977), ‘Weighted shifts and products of subnormal operators’, Ind. U. Math. J. 26, 839845.Google Scholar
Lubin, A. (1978), ‘A subnormal semigroup without normal extension’, Proc. Amer. Math. Soc. 68, 176178.Google Scholar
MacNerney, J. S. (1962), ‘Hermitian moment sequences’, Trans. Amer. Math. Soc. 103, 4581.CrossRefGoogle Scholar
Shields, A. L. (1974), Weighted shift operators and analytic function theory (Math Surveys, 13, Amer. Math. Soc).Google Scholar
Yoshino, T. (1973), ‘On the commuting extensions of nearly normal operators’, Tohoku Math. J. 25, 163272.Google Scholar