Hostname: page-component-848d4c4894-r5zm4 Total loading time: 0 Render date: 2024-07-06T18:22:23.858Z Has data issue: false hasContentIssue false

A representation theorem for a complete Boolean algebra of projections*

Published online by Cambridge University Press:  14 November 2011

H. R. Dowson
Affiliation:
Department of Mathematics, University of Glasgow
T. A. Gillespie
Affiliation:
Department of Mathematics, University of Edinburgh

Synopsis

Let B be a complete Boolean algebra of projections on a complex Banach space X and let (B) denote the closed algebra of operators generated by B in the norm topology. It is shown that there is a complex Hilbert space H, a complete Boolean algebra B0 of self-adjoint projections on H, and an algebraic isomorphism of B onto B. This isomorphism is bicontinuous when B and B are endowed with the norm topologies, the weak operator topologies or the ultraweak operator topologies. It is also bicontinuous on bounded sets with respect to the strong operator topologies on B and B. As an application, it is shown that the weak and ultraweak operator topologies in fact coincide on B.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1979

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1Berberian, S. K.. lectures in functional analysis and operator theory (New York: Springer, 1974).CrossRefGoogle Scholar
2Dieudonné, J.. Sur la bicommutante d'une algèbre d'opérateurs. Portugal. Math. 14 (1955), 3538.Google Scholar
3Dixmier, J.. Les algèbres d'opérateurs dans l'espace hilbertien (Paris: Gauthier-Villars, 1969).Google Scholar
4Dowson, H. R.. On the algebra generated by a hermitian operator. Proc. Edinburgh Math. Soc. 18 (1972), 8991.CrossRefGoogle Scholar
5Dunford, N. and Schwartz, J. T.. Linear operators, 3 (New York: Wiley, 1971).Google Scholar
6Edwards, D. A. and Ionescu Tulcea, C.. Some remarks on commutative algebras of operators on Banach spaces. Trans. Amer. Math. Soc. 93 (1959), 541551.CrossRefGoogle Scholar
7Gillespie, T. A.. Cyclic Banach spaces and reflexive operator algebras. Proc. Roy. Soc. Edinburgh Sect. A 78 (1978), 225235.Google Scholar
8Gillespie, T. A.. Boolean algebras of projections and reflexive algebras of operators. Proc. London Math. Soc. 37 (1978), 5674.Google Scholar
9Halmos, P. R.. Introduction to Hilbert space and the theory of spectral multiplicity (New York: Chelsea, 1951).Google Scholar
10Segal, I. E.. Decompositions of operator algebras II. Mem. Amer. Math. Soc. 9 (1951).Google Scholar
11Segal, I. E.. Equivalences of measure spaces. Amer. J. Math. 73 (1951), 275313.Google Scholar
12Zaanen, A. C.. Integration (Amsterdam: North Holland, 1967).Google Scholar