
In 2010 a question of Arhangel'skii's highlighted a gap in the knowledge of k_��-spaces. His specific question had in fact been answered by Siwiec in 1976, but the highlighted gap still remains. We introduce the simple idea of pure quotient maps, extend Morita's theorem to these, and use Fell's topology to show that every quotient map onto a k_��-space can be 'purified'; and thus fill the gap, elucidate the structure of k_��-spaces, and obtain a fuller answer to Arhangel'skii's question.
The paper was submitted under another title. The readers should instead refer to arXiv:2108.05202
General Topology (math.GN), FOS: Mathematics, 54B15
General Topology (math.GN), FOS: Mathematics, 54B15
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 0 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
