Large cardinals and continuity of coordinate functionals of filter bases in Banach spaces

Abstract

Assuming the existence of certain large cardinal numbers, we prove that for every projective filter $\mathcal{F}$ over the set of natural numbers, $\mathcal{F}$-bases in Banach spaces have continuous coordinate functionals. In particular, this applies to the filter of statistical convergence, thereby we solve a problem by V. Kadets (at least under the presence of certain large cardinals). In this setting, we recover also a result of Kochanek who proved continuity of coordinate functionals for countably generated filters (Studia Math., 2012).

10 pp