Covering versus partitioning with the Cantor space
Abstract
What topological spaces can be partitioned into copies of the Cantor space ? An obvious necessary condition is that a space can be partitioned into copies of only if it can be covered with copies of . We prove three theorems concerning when this necessary condition is also sufficient. If is a metrizable space and (the least limit cardinal ), then can be partitioned into copies of if and only if can be covered with copies of . To show this cardinality bound is sharp, we construct a metrizable space of size that can be covered with copies of , but not partitioned into copies of . Similarly, if is first countable and , then can be partitioned into copies of if and only if can be covered with copies of . On the other hand, there is a first countable space of size that can be covered with copies of , but not partitioned into copies of . Finally, we show that a completely metrizable space can be partitioned into copies of if and only if it can be covered with copies of if and only if it has no isolated points.
Keywords
Cite
@article{arxiv.2103.05725,
title = {Covering versus partitioning with the Cantor space},
author = {Will Brian},
journal= {arXiv preprint arXiv:2103.05725},
year = {2021}
}