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A Set-Valued Generalization of Fan's Best Approximation Theorem

Published online by Cambridge University Press:  20 November 2018

Xie Ping Ding
Affiliation:
Department of Mathematics, Sichuan Normal University, Chengdu, Sichuan, China
Kok-Keong Tan
Affiliation:
Department of Mathematics, Statistics and Computing Science Dalhousie University, Halifax, Nova Scotia, CanadaB3H 3J5
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Abstract

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Let (E, T) be a Hausdorff topological vector space whose topological dual separates points of E, X be a non-empty weakly compact convex subset of E and W be the relative weak topology on X. If F: (X, W) → 2(E,T) is continuous (respectively, upper semi-continuous if £ is locally convex), approximation and fixed point theorems are obtained which generalize the corresponding results of Fan, Park, Reich and Sehgal-Singh-Smithson (respectively, Ha, Reich, Park, Browder and Fan) in several aspects.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1992

References

1. Aubin, J.P., Mathematical Methods of Game and Economic Theory, Revised Edition, North-Holland, Amsterdam/ New York/Oxford, 1982.Google Scholar
2. Browder, F.E., On a sharpened form of the Schauder fixed point theorem, Proc. Nat. Acad. Sci. U.S.A. 74 (1977), 47494751.Google Scholar
3. Ding, X.P. and Tan, K.K., A minimax inequality with applications to existence of equilibrium point and fixed point theorems, Colloquium Math, to appear.Google Scholar
4. Fan, K., A generalization of Tychonoff's fixed point theorem, Math. Ann. 142 (1961), 305310.Google Scholar
5. Fan, K., Extensions of two fixed point theorems of Browder F.E., Math. Z. 112 (1969), 234240.Google Scholar
6. Fan, K., Some properties of convex sets related to fixed point theorems, Math. Ann. 226 (1984), 519537.Google Scholar
7. Ha, C.W., On a minimax inequality of Ky Fan, Proc. Amer. Math. Soc. 99 (1987), 680682.Google Scholar
8. Lin, T.C., A note on a theorem of Ky Fan, Canad. Math. Bull. 22 (1979), 513515.Google Scholar