arXiv subjects

G. J. Ridderbos

Publications and source records attributed to G. J. Ridderbos.

2 recordsLinked to original sources

arXiv2011

Weak extent, submetrizability and diagonal degrees

We show that if $X$ has a zero-set diagonal and $X^2$ has countable weak extent, then $X$ is submetrizable. This generalizes earlier results from Martin and Buzyakova. Furthermore we show that if $X$ has a regular $G_δ$-diagonal and $X^2$ has countable weak extent, then $X$ condenses onto a second countable Hausdorff space. We also prove several cardinality bounds involving various types of diagonal degree.

math.GN↗

arXiv2005

A note on an example by van Mill

Improving on an earlier example by J. van Mill, we prove that there exists a zero-dimensional compact space of countable pi-weight and uncountable character which is homogeneous under MA+notCH, but not under CH.

math.GN↗