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Isometric Shift Operators on C(X)

Published online by Cambridge University Press:  20 November 2018

F. O. Farid
Affiliation:
Department of Mathematics and Statistics University ofGuelph Guelph, Ontario N1G2WJ
K. Varadarajan
Affiliation:
Department of Mathematics University of Calgary Calgary, Alberta T2N JN4
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Abstract

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Recently A. Gutek, D. Hart, J. Jamison and M. Rajagopalan have obtained many significiant results concerning shift operators on Banach spaces. Using a result of Holsztynski they classify isometric shift operators on C(X) for any compact Hausdorff space X into two (not necessarily disjoint) classes. If there exists an isometric shift operator T: C(X) → C(X) of type II, they show that X is necessarily separable. In case T is of type I, they exhibit a paticular infinite countable set of isolated points in X. Under the additional assumption that the linear functional Γ carrying fC(X) to Tf(p) ∊ is identically zero, they show that D is dense in X. They raise the question whether D will still be dense in X even when Γ ≠ 0. In this paper we give a negative answer to this question. In fact, given any integer l ≥ 1, we construct an example of an isometric shift operator T: C(X) —> C(X) of type I with X \ having exactly / elements, where is the closure of D in X.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1994

References

1. Crownover, R. M., Commutants of shifts on Banach spaces, Michigan Math. J. 19(1972), 233247.Google Scholar
2. Gutek, A., Hart, D., Jamison, J. and Rajagopalan, M., Shift Operators on Banach Spaces, J. Funct. Anal. 101(1991),97-119.Google Scholar
3. Holub, J. R., On Shift Operators, Canad. Math. Bull. 31(1988), 8594.Google Scholar
4. Holsztynski, W., Continuous mappings induced by isometries of spaces of continuous functions, Studia Math. 26(1966), 133136.Google Scholar