Closed graph multi-selections
Volume 211 / 2011
Fundamenta Mathematicae 211 (2011), 85-99
MSC: 54C60, 54C65.
DOI: 10.4064/fm211-1-5
Abstract
A classical Lefschetz result about point-finite open covers of normal spaces is generalised by showing that every lower semi-continuous mapping from a normal space into the nonempty compact subsets of a metrizable space admits a closed graph multi-selection. Several applications are given as well.
