Topological groups with a certain point-countable cover
The authors study topological groups possessing special covers or networks. Their general result has several consequences on properties of groups or existence of various open subgroups as, e.g., Corollary 2.9: If a topological group \(G\) is a k-space having a star-countable k-network, then \(G\) contains an open subgroup that is an \(\aleph_0\)-space; Theorem 3.2: Every topological group with a \(\sigma\)-hereditarily closure-preserving k-network is an \(\aleph\)-space.
scientific article; zbMATH DE number 1741956
scientific article