Density topology on R is not a Borel subset of its Stone-Čech compactification
R with density topology is known as a pseudo-complete, regularly cocompact, strongly \(\alpha\)-favourable Baire space. It is shown here that it is not a Borel subset of its Stone-Čech compactification. It is also not \(\sigma\)-compact and behaves feebly with Čech- completeness property.
strongly \(\alpha \) -favourable Baire space
scientific article; zbMATH DE number 3933996