Completeness in topological vector spaces and filters on N

Abstract

We study completeness of a topological vector space with respect to different filters on the set N of all naturals. In the metrizable case all these kinds of completeness are the same, but in non-metrizable case the situation changes. For example, a space may be complete with respect to one ultrafilter on N, but incomplete with respect to another. Our study was motivated by [Aizpuru, List\'an-Garc\'ia and Rambla-Barreno; Quaest. Math., 2014] and [List\'an-Garc\'ia; Bull. Belg. Math. Soc. Simon Stevin, 2016] where for normed spaces the equivalence of the ordinary completeness and completeness with respect to f-statistical convergence was established.