Measure of compactness for filters in product spaces: Kuratowski–Mròwka in CAP revisited

Autor: Frédéric Mynard, William Trott
Rok vydání: 2016
Předmět:
Zdroj: Topology and its Applications. 200:251-267
ISSN: 0166-8641
DOI: 10.1016/j.topol.2015.06.013
Popis: The first author introduced a measure of compactness for families of sets, relative to a class of filters, in the context of convergence approach spaces. We characterize a variety of maps (types of quotient maps, closed maps, and variants of perfect maps) as those respecting this measure of compactness under one form or another. We establish a product theorem for measure of compactness that yields as instances new product theorems for spaces and maps, and new product characterizations of spaces and maps, thus extending existing results from the category of convergence spaces to that of convergence approach spaces. In particular, results of the Mrowka–Kuratowski type are obtained, shedding new light on existing results for approach spaces.
Databáze: OpenAIRE