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Application of a Selection Theorem to Hyperspace Contractibility

Published online by Cambridge University Press:  20 November 2018

D. W. Curtis*
Affiliation:
Louisiana State University, Baton Rouge, Louisiana
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For X a metric continuum, 2X denotes the hyper space of all nonempty subcompacta, with the topology induced by the Hausdorff metric H, and C(X) ⊂ 2X the hyperspace of subcontinua. These hyperspaces are continua, in fact are arcwise-connected, since there exist order arcs between each hyperspace element and the element X. They also have trivial shape, i.e., maps of the hyperspaces into ANRs are homotopic to constant maps. For a detailed discussion of these and other general hyperspace properties, we refer the reader to Nadler's monograph [4].

The question of hyperspace contractibility was first considered by Wojdyslawski [8], who showed that 2X and C(X) are contractible if X is locally connected. Kelley [2] gave a more general condition (now called property K) which is sufficient, but not necessary, for hyperspace contractibility. The continuum X has property K if for every there exists δ > 0 such that, for every pair of points x, y with d(x, y) < δ and every subcontinuum M containing x, there exists a subcontinuum N containing y with .

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1985

References

1. Arhangel'skii, A., Open and almost open mappings of topological spaces, Soviet Math. Dokl. 3 (1962), 17381741.Google Scholar
2. Kelley, J. L., Hyperspaces of a continuum, Trans. Amer. Math. Soc. 52 (1942), 2236.Google Scholar
3. Michael, E., Convex structures and continuous selections, Can. J. Math. 11 (1959), 556575.Google Scholar
4. Nadler, S. B. Jr., Hyperspaces of sets (Marcel Dekker, Inc., New York, 1978).Google Scholar
5. Nishiura, T. and Rhee, C. J., Contractibility of the hyperspace of subcontinua, Houston J. Math. 5 (1982), 119127.Google Scholar
6. Rhee, C.J., On a contractible hyperspace condition, Topology Proceedings 7 (1982), 147155.Google Scholar
7. Wardle, R. W., On a property of J. L. Kelley, Houston J. Math. 3 (1977), 291299.Google Scholar
8. Wojdyslawski, M., Sur la contractilité des hyperespaces des continus localement connexes, Fund. Math. 30 (1938), 247252.Google Scholar