P-ideal dichotomy and Tukey order
Fundamenta Mathematicae
MSC: Primary 03E02; Secondary 03E10, 05D10
DOI: 10.4064/fm240323-26-6
Published online: 30 August 2024
Abstract
The P-ideal dichotomy is a simple and natural principle about P-ideals of countable subsets of some index set. It has proven to be particularly useful in problems involving sequential convergence in topological spaces. This is explored further here with the aim to relate it to the theory of Tukey reductions of directed sets.