5 papers
The Wallace problem and countably compact torsion-free Abelian groups in ZFC
Juliane Trianon Fraga, Vinicius de Oliveira Rodrigues
We prove in ZFC that every torsion-free Abelian group of cardinality admits a Hausdorff countably compact group topology without nontrivial convergent sequences. In p…
Countable compactness in powers of topological groups and Ramsey theoretic variations of compactness
Vinicius de Oliveira Rodrigues, Paul Jan Szeptycki, Artur Hideyuki Tomita
Countable compactness need not be preserved by finite products. Motivated by compactness notions for maps indexed by finite subsets of , we introduce cascade countable compactne…
On the possible values of the Rearrangement Number
Vinicius de Oliveira Rodrigues
The rearrangement number is the least cardinality of a collection of permutations of such that every conditionally convergent real series is disrupted by some…
Almost Disjointness Principles and -Space Cardinals
Vinicius de Oliveira Rodrigues
Banakh and Bazylevych introduced separation-axiom variants , for , of the cardinal , together with a cardinal lying…
On covering properties of end and ray spaces
Rodrigo Rey Carvalho, Matheus Duzi, Vinicius de Oliveira Rodrigues
We provide new results on combinatorial characterizations of covering properties in end spaces and ray spaces. In particular, we characterize the Lindelöf degree, the extent, the…