Weakly Corson compact trees
arXiv:2106.11830 · doi:10.1007/s11117-022-00874-5
Abstract
We introduce and study a new topology on trees, that we call the countably coarse wedge topology. Such a topology is strictly finer than the coarse wedge topology and it turns every chain complete, rooted tree into a Fréchet--Urysohn, countably compact topological space. We show the rôle of such topology in the theory of weakly Corson and weakly Valdivia compacta. In particular, we give the first example of a compact space whose every closed subspace is weakly Valdivia, yet is not weakly Corson. This answers a question due to Ondřej Kalenda.