Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-26T04:51:33.739Z Has data issue: false hasContentIssue false

Antipodal coincidence sets and stronger forms of connectedness

Published online by Cambridge University Press:  17 April 2009

J.E. Harmse
Affiliation:
Department of Mathematics, University of Auckland, Auckland, New Zealand.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A new notion of α-connectedness (α-path connectedness) in general topological spaces is introduced and it is proved that for a real-valued function defined on a space with this property, the cardinality of the antipodal coincidence set is at least as large as the cardinal number α. In particular, in linear topological spaces, the antipodal coincidence set of a real-valued function has cardinality at least that of the continuum. This could be regarded as a treatment of some Borsuk-Ulam type results in the setting of general topology.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1985

References

[1]Borsuk, K., “Drei Sätze über die n-dimensionale Euklidische Sphäre”, Fund. Math. 20 (1933), 177190CrossRefGoogle Scholar
[2]Bourgin, D.G., “On some separation arid mapping theorems”, Comment. Math. Helv. 29 (1955), 199214.CrossRefGoogle Scholar
[3]Conner, P.E. and Floyd, E.E., “Fixed point free involutions and equivariant maps”, Bull. Amer. Math. Soc. 66 (1960), 416441.CrossRefGoogle Scholar
[4]Connett, J.E., “On the cohomology of the fixed-point sets and coincidence-point sets”, Indiana Univ. Math. J. 24 (1975), 6276311CrossRefGoogle Scholar
[5]Dyson, F.J., “Continuous functions defined on spheres”, Ann. of Math. 54 (1951), 534536.CrossRefGoogle Scholar
[6]Eisenberg, M., Topology (Holt, Rinehart and Winston, New York, London, 1974).Google Scholar
[7]Granas, A., “An extension to functional spaces of Borsuk-Ulam theorem on antipodes”, Bull. Acad. Polon. Sci. Sér. Sci. Math. 10 (1962), 8186.Google Scholar
[8]Holm, P. and Spanier, E.H., “Involutions and Fredliolm maps”, Topology 10 (1971), 203218CrossRefGoogle Scholar
[9]Jaworowski, J., “A continuous version of the Borsuk-Ulam theorem”, Proc. Amer. Math. Soc. 82 (1981), 112114.CrossRefGoogle Scholar
[10]Jaworowski, J., “Fibre preserving maps of sphere bundles into vector space bundles”, Proceedings of the Fixed Point Theory Workshop, Sherbrooke, 1980, 155162 (Lecture Notes in Mathematics, 886. Springer-Verlag, Berlin, Heidelberg, New York, 1981).Google Scholar
[11]Jaworowski, J., “An antipodal coincidence theorem for families of compact perturbations”, Nonlinear analysis and applications, 191195 (Lecture Notes in Pure and Applied Mathematics, 80. Marcell Dekkar, New York, 1982).Google Scholar
[12]Jaworowski, J., “Fibre preserving free involutions”, preprint.Google Scholar
[13]Joshi, K.D., “A non-symmetric generalisation of the Borsuk Ulam theorem”, Fund. Math. 80 (1973), 1333CrossRefGoogle Scholar
[14]Joshi, K.D., “A non-symmetric generalisation of theorems of Dyson and Livesay”, Fund. Math. 90 (1975), 3543.CrossRefGoogle Scholar
[15]Kakutani, S., “A proof that there exists a circumscribing cube about any bounded closed convex set in R3”, Ann. of Math. 43 (1942), 739741.CrossRefGoogle Scholar
[16]Livesay, G.R., “On a theorem of F.J. Dyson”, Ann. of Math. 59 (1951), 227229CrossRefGoogle Scholar
[17]Spiez, S., “On generalisations of theorems of Borsuk-Ulam, Dyson and Livesay”, Bull. Acad. Polon. Sci. Sér. Sci. Math. Astronom. Phys. 26 (1978), 325333Google Scholar
[18]Yamabe, E. and Yujobo, Z., “On the continuous function defined on a sphere”, Osaka Math. J. 2 (1950), 1922Google Scholar
[19]Yang, C.-T., “On theorems of Borsuk-Ulam, Kakutani-Yamabe-Yujobo, and Dyson, I”, Ann. of Math. 60 (1954), 262282CrossRefGoogle Scholar
[20]Yang, C.-T., “On theorems of Borsuk-Ulan, Kakutani-Yamabe-Yujobo, and Dyson, II”, Ann. of Math. 62 (1955), 271283CrossRefGoogle Scholar
[21]Yang, C.-T., “Continuous functions from spheres to Euclidean spaces”, Ann. of Math. 62 (1955), 281292.CrossRefGoogle Scholar