Title of article :
Between compactness and completeness
Author/Authors :
Beer، نويسنده , , Gerald، نويسنده ,
Issue Information :
دوماهنامه با شماره پیاپی سال 2008
Abstract :
Call a sequence in a metric space cofinally Cauchy if for each positive ε there exists a cofinal (rather than residual) set of indices whose corresponding terms are ε-close. We give a number of new characterizations of metric spaces for which each cofinally Cauchy sequence has a cluster point. For example, a space has such a metric if and only each continuous function defined on it is uniformly locally bounded. A number of results exploit a measure of local compactness functional that we introduce. We conclude with a short proof of Romagueraʹs Theorem: a metrizable space admits such a metric if and only if its set of points having a compact neighborhood has compact complement.
Keywords :
Cofinally complete metric , Cofinally Cauchy sequence , Atsuji metric , Complete metric , Hausdorff distance , UC metric
Journal title :
Topology and its Applications
Journal title :
Topology and its Applications