The core compactly generated topology

Abstract

M. Escardó et al. asked whether the core compactly generated topology of a sober space is again sober and the sobrification of a core compactly generated space again core compactly generated. In this note, we answer the problem by displaying a counterexample, which reveals that the core compactly generated spaces are not closed under sobrifications. Meantime, we obtain that the core compactly generated spaces are closed under ω-well-filterifications and D-completions. Furthermore, we find that the core compactly generated topology of the Smyth power space of a well-filtered space coincides with the Scott topology. Finally, we provide a characterization for the core-compactness of core compactly generated spaces.

11 pages, 1 figure