On lower semicontinuity of the restricted center multifunction
DOI:
https://doi.org/10.33993/jnaat381-904Keywords:
restricted center, restricted center multifunction, lower semicontinuity of multifunctionAbstract
Given a finite dimensional subspace \(V\) and a certain family \({\mathcal F}\) of nonempty closed and bounded subsets of \( {\mathcal C}_0(T,U)\), where \(T\) is a locally compact Hausdorff space and \(U\) is a strictly convex Banach space, we investigate here lower semicontinuity of the restricted center multifunction \(C_{V}:{\mathcal F} \rightrightarrows V.\) In particular, we establish a Haar-like intrinsic characterization of finite dimensional subspaces \(V\) of \({\mathcal C}_0(T,U)\) which yields lower semicontinuity of \(C_{V}.\)Downloads
References
Beer, G. and Pai, D., On convergence of convex sets and relative Chebyshev centers, J. Approx. Theory, 62, pp. 147-169, 1990, https://doi.org/10.1016/0021-9045(90)90029-p DOI: https://doi.org/10.1016/0021-9045(90)90029-P
Blatter, J., Morris P.D. and Wulbert D.E., Continuity of the set-valued metric projection, Math. Ann, 178 , pp. 12-24, 1968, https://doi.org/10.1007/bf01350621 DOI: https://doi.org/10.1007/BF01350621
Blatter, J. and Schumaker, L., The set of continuous selections of a metric projection in C(X),, J. Approx. Theory, 36, pp. 141-155, 1982, https://doi.org/10.1016/0021-9045(82)90061-2 DOI: https://doi.org/10.1016/0021-9045(82)90061-2
Brosowski, B. and Wegmann, R., On the lower semicontinuity of the set-valued metric projection, J. Approx. Theory, 8, pp. 84-100, 1973, https://doi.org/10.1016/0021-9045(73)90033-6 DOI: https://doi.org/10.1016/0021-9045(73)90033-6
Brown, A.L., On continuous selections for metric projections in spaces of continuous functions, J. Funct. Anal., 8, pp. 431-449, 1971, https://doi.org/10.1016/0022-1236(71)90005-x DOI: https://doi.org/10.1016/0022-1236(71)90005-X
Deutsch, F., Continuous selections for metric projections: Some recent progress, in "Approximation Theory V", Chui, C.K., Schumaker, L.L. and Ward, J.D. (eds.), pp. 319-322, Academic Press, New York, 1986.
Deutsch, F., An exposition of recent results on continuous metric selections, in "Numerical Methods of Approximation Theory", Collatz, L., Meinardus, G. and Nurnberger, G. (eds.), ISNM 81, pp. 67-80, Birkhauser Verlag, Basel, 1987. DOI: https://doi.org/10.1007/978-3-0348-6656-9_6
Indira K. and Pai, D., Hausdorff strong uniqueness in simultaneous approximation. Part I, in "Approximation Theory XI: Gatlinburg 2004", Chui, C.K, Neamtu, M. and Schumaker, L.L. (eds.), pp. 101-118, Nashboro Press, Brentwood, TN, USA, 2005.
Lazar, A.J., Morris, P.D. and Wulbert, D.E., Continuous selections for metric projections, J. Funct. Anal., 3, pp. 193-216, 1969, https://doi.org/10.1016/0022-1236(69)90040-8 DOI: https://doi.org/10.1016/0022-1236(69)90040-8
Li, W., Strong uniqueness and Lipschitz continuity of metric projections: A generalization of the Classical Haar theory, J. Approx. Theory, 56 , pp. 164-184, 1989, https://doi.org/10.1016/0021-9045(89)90108-1 DOI: https://doi.org/10.1016/0021-9045(89)90108-1
Li, W., Various continuities of metric projection in C₀(T,X), J. Approx. Theory, 57, pp. 150-168, 1989, https://doi.org/10.1016/0021-9045(89)90053-1 DOI: https://doi.org/10.1016/0021-9045(89)90053-1
Li, W., An intrinsic characterization of lower semicontinuity of the metric projection in C₀(T,X), J. Approx. Theory, 57, pp. 136-149, 1989, https://doi.org/10.1016/0021-9045(89)90052-x DOI: https://doi.org/10.1016/0021-9045(89)90052-X
Li, W., Continuous Selections for Metric Projection and Interpolating Subspaces, in "Approximation & Optimization", Vol. 1, Lang, P., Fankfurt am Main, 1991.
Mach, J., Continuity properties of Chebyshev centers, J. Approx. Theory, 29, pp. 223-230, 1980, https://doi.org/10.1016/0021-9045(80)90127-6 DOI: https://doi.org/10.1016/0021-9045(80)90127-6
Mhaskar, H.N. and Pai, D.V., Fundamentals of Approximation Theory, CRC Press, Boca Raton, Florida, 2000.
Nurnberger, G. and Sommer, M., Weak Chebyshev subspaces and continuous selections for the metric projection, Trans. Amer. Math. Soc., 238, pp. 129-138, 1978, https://doi.org/10.1090/s0002-9947-1978-0482912-9 DOI: https://doi.org/10.1090/S0002-9947-1978-0482912-9
Pai, D.V., Strong uniqueness of best simultaneous approximation, J. Indian Math. Soc. (N.S.), 67, pp. 201-215, 2000.
Pai, D.V. and Indira, K., On well-posedness of some problems in approximation theory, in "Advances in Constructive Approximation", Neamtu, M. and Saff, E.B. (eds.), pp. 371-392, Nashboro Press, Brentwood, TN, 2004.
Pai, D. and Indira, K., Hausdorff strong uniqueness in simultaneous approximation. Part II, in "Frontiers in Interpolation and Approximation", Govil, N.K. Mhaskar, H.N., Mohapatra, R.N., Nashed, Z.and Szabados, J. (eds.), pp. 365-380, Chapman & Hall/CRC, Taylor & Francis Group, Boca Raton, USA, 2007.
Pai, D.V. and Nowroji, P.T., On restricted centers of sets, J. Approx. Theory, 66, pp. 170-189, 1991, https://doi.org/10.1016/0021-9045(91)90119-u DOI: https://doi.org/10.1016/0021-9045(91)90119-U
Panda, B.B. and Kapoor, O.P., On farthest points of sets, J. Math. Anal. Appl., 62, pp. 345-353, 1978, https://doi.org/10.1016/0022-247x(78)90131-2 DOI: https://doi.org/10.1016/0022-247X(78)90131-2
Zuhovickii, S.I. and Steckin, S.B., On the approximation of abstract functions, Amer. Math. Soc. Transl., 16, pp. 401-406, 1960, https://doi.org/10.1090/trans2/016/20 DOI: https://doi.org/10.1090/trans2/016/20
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2015 Journal of Numerical Analysis and Approximation Theory
This work is licensed under a Creative Commons Attribution 4.0 International License.
Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.