Article
Keywords:
set-valued mapping; lower semi-continuous; upper semi-continuous; selection; countable-dimensional space
Summary:
Every l.s.c\. mapping from a paracompact space into the non-empty, closed, convex subsets of a (not necessarily convex) $G_\delta $-subset of a Banach space admits a single-valued continuous selection provided every such mapping admits a convex-valued usco selection. This leads us to some new partial solutions of a problem raised by E. Michael.
References:
[1] Gutev V.:
Open mappings looking like projections. Set-valued Analysis 1 (1993), 247-260.
MR 1249265 |
Zbl 0818.54011
[4] Michael E.:
A theorem on semi-continuous set-valued functions. Duke Math. J. 26:4 (1959), 647-656.
MR 0109343 |
Zbl 0151.30805
[6] Michael E.: in Open problems in Topology, J. van Mill and J.M. Reed, Chapter 17, 272-278, North-Holland, Amsterdam 1990.
MR 1078636 |
Zbl 1171.90455
[7] Michael E.:
Some refinements of a selection theorem with 0-dimensional domain. Fund. Math. 140 (1992), 279-287.
MR 1173768 |
Zbl 0763.54015
[8] J. van Mill:
Infinite Dimensional Topology. Prerequisites and Introduction, North-Holland, Amsterdam, 1989.
MR 0977744 |
Zbl 1027.57022
[9] Nedev S.:
Selection and factorization theorems for set-valued mappings. Serdica 6 (1980), 291-317.
MR 0644284 |
Zbl 0492.54006