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arXiv · 1301.5297

Hereditarily supercompact spaces

Abstract

A topological space $X$ is called hereditarily supercompact if each closed subspace of X is supercompact. By a combined result of Bula, Nikiel, Tuncali, Tymchatyn, and Rudin, each monotonically normal compact Hausdorff space is hereditarily supercompact. A dyadic compact space is hereditarily supercompact if and only if it is metrizable. Under (MA + not CH) each separable hereditarily supercompact space is hereditarily separable and hereditarily Lindel\"of. This implies that under (MA + not CH) a scattered compact space is metrizable if and only if it is separable and hereditarily supercompact. The hereditary supercompactness is not productive: the product [0,1] x \alpha D of the closed interval and the one-point compactification \alpha D of a discrete space D of cardinality |D|\ge non(M) is not hereditarily supercompact (but is Rosenthal compact and uniform Eberlein compact). Moreover, under the assumption cof(M)=\omega_1 the space [0,1] x \alpha D contains a closed subspace X which is first countable and hereditarily paracompact but not supercompact.

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Taras Banakh, Zdzislaw Kosztolowicz, Slawomir Turek. 2013-01-22. Hereditarily supercompact spaces. https://doi.org/10.1016/j.topol.2013.10.028

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