Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-26T05:17:32.381Z Has data issue: false hasContentIssue false

On Mosco convergence of convex sets

Published online by Cambridge University Press:  17 April 2009

Gerald Beer
Affiliation:
Department of Mathematics, California State University, Los Angeles, Los Angeles, CA 90032, United States of America
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.

We present a natural topology compatible with the Mosco convergence of sequences of closed convex sets in a reflexive space, and characterise the topology in terms of the continuity of the distance between convex sets and fixed weakly compact ones. When the space is separable, the topology is Polish. As an application, we show that in this context, most closed convex sets are almost Chebyshev, a result that fails for the stronger Hausdorff metric topology.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1988

References

[1]Attouch, H., ‘Famille d'opérateurs maximaux monotones et mésurabilité’, Ann. Mat. Pura Appl. (4) 120 (1979), 35111.CrossRefGoogle Scholar
[2]Attouch, H., Variational convergence for functions and operators (Pitman Publishers, Boston, 1984).Google Scholar
[3]Baronti, M. and Papini, P., ‘Convergence of sequences of sets, in’, Methods of functional analysis in approximation theory ISNM 76 (Birkhäuser Verlag, 1986).Google Scholar
[4]Beer, G., ‘Metric spaces with nice closed balls and distance functions for closed sets’, Bull Austral. Soc. 35 (1987), 8196.Google Scholar
[5]Beer, G., ‘On the straight line path for convex sets’, Israel J. Math. 58 (1987), 205212.CrossRefGoogle Scholar
[6]Beer, G., ‘Metric projections and the Fell topology’, (submitted).Google Scholar
[7]Beer, G., ‘Convergence of continuous linear functionals and their level sets’, (submitted).Google Scholar
[8]Brown, A., ‘A rotund reflexive space having a subspace of codimension two with a discontinuous metric projection’, Michigan Math. J. 21 (1976), 145151.Google Scholar
[9]Castaing, C. and Valadier, M., Convex analysis and measurable multifunctions: Lecture notes in mathematics 580 (Springer-Verlag, Berlin, 1977).Google Scholar
[10]Christensen, J.P.R., ‘Theorems of Namioka and R.E. Johnson type for upper semicontinuous and compact valued set-valued mappings’, Proc. Amer. Math. Soc. 88 (1982), 649655.CrossRefGoogle Scholar
[11]DeBlasi, F. and Myjak, J., ‘On the minimum, distance to a closed convex set in a Banach space’, Bull. Acad. Pol. Sci. 29 (1981), 373376.Google Scholar
[12]De Blasi, F. and Myjak, J., ‘Weak convergence of convex sets in Banach spaces’, Arch. Math. 47 (1986), 448456.CrossRefGoogle Scholar
[13]Deutsch, F., Pollul, W. and Singer, I., ‘On set-valued metric projections, Hahn-Banach extension maps and spherical image maps’, Duke Math. J. 40 (1973), 355370.CrossRefGoogle Scholar
[14]Deutsch, F. and Kenderov, P., ‘Continuous selections and approximate selections for set-valued mappings and applications to metric projections’, SIAM J. Math. Anal 14 (1983), 185194.CrossRefGoogle Scholar
[15]Diestel, J., Geometry of Banach spaces–selected topics: Lecture notes in mathematics 485 (Springer-Verlag, New York, 1975).Google Scholar
[16]Fell, J., ‘A. Hausdorff topology for the closed subsets of a locally compact non-Hausdorff space’, Proc. Amer. Math. Soc. 13 (1962), 472476.CrossRefGoogle Scholar
[17]Fort, M., ‘Points of continuity of semi-continuous functions’, Publ. Math. Debrecen 2 (1951), 100102.CrossRefGoogle Scholar
[18]Francaviglia, S., Lechicki, A. and Levi, S., ‘Quasi-uniformization of hyperspaces and convergence of nets of semicontinuous multifunctions’, J. Math. Anal. Appl (1985), 347370.Google Scholar
[19]Garkavi, A., ‘On Chebyshev and almost Chebyshev subspaces’, Izv. Akad. Nauk SSSR Ser.Mat. 28 (1964), 799818.(translation in Amer. Math. Soc. Transl. 96 (1970), 153–175).Google Scholar
[20]Holmes, R., A course in optimization and best approximation: Lecture notes in mathematics 257 (Springer-Verlag, New York, 1972).Google Scholar
[21]John, K. and Zizler, V., ‘A renorming of dual spaces’, Israel J. Math. 12 (1972), 331336.CrossRefGoogle Scholar
[22]Joly, J., ‘Une famille de topologies sur l'ensemble des fonctions convexes pour lesquelles la polarité est bicontinue’, J. Math. Pures Appl 52 (1973), 421441.Google Scholar
[23]Kenderov, P., ‘Points of single valuedness of multivalued metric projections’, C. R. Acad. Bulgare Sci. 29 (1976), 773777.Google Scholar
[24]Klein, E. and Thompson, A., Theory of correspondence (Wiley, Toronto, 1984).Google Scholar
[25]Kuratowski, K., Topology 1 (Academic Press, New York, 1966).Google Scholar
[26]Levi, S. and Lechicki, A., ‘Wijsmnan convergence in the hyperspace of a metric space’, Boll. Un Mat. Ital 5-B (1987 pages 435452).Google Scholar
[27]Michael, E., ‘Topologies on spaces of subsets’, Trans. Amer. Math. Soc. 71 (1951), 152182.Google Scholar
[28]Mosco, U., ‘Convergence of convex sets and of solutions of variational inequalities’, Adv. in Math. 3 (1969), 510585.CrossRefGoogle Scholar
[29]Mosco, U., ‘On the continuity of the Young–Fenchel transform’, J. Math. Anal. Appl. 35 (1971), 518535.CrossRefGoogle Scholar
[30]Salinetti, G. and Wets, R., ‘On the relation between two types of convergence for convex functions’, J. Math. Anal. Appl. 60 (1977), 211226.CrossRefGoogle Scholar
[31]Salinetti, G. and Wets, R., ‘On the convergence of sequences of convex sets in finite dimensions’, SIAM Rev. 21 (1979), 1833.CrossRefGoogle Scholar
[32]Sonntag, Y., Convergence au sens de Mosco; théorie et applications à l’approximation des solutions d'inéquations (Thèse d'Etat, Université de Provence, Marseille, 1982).Google Scholar
[33]Taylor, A. and Lay, D., Introduction to functional analysis (Wiley, New York, 1980).Google Scholar
[34]Zolezzi, T., Approximazioni e perturbazioni di problemi di minimo. (in preparation).Google Scholar