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Cosmicity of Rω1-factorizable spaces

Determine whether every Rω1-factorizable Tychonoff space is cosmic; specifically, ascertain whether any topological space X for which every continuous function f: X → Rω1 factors through a continuous map into a second-countable space necessarily has a countable network.

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Background

The paper introduces Rω1-factorizable spaces: X is Rω1-factorizable if every continuous map f: X → Rω1 factors through a second-countable space. This is equivalent to X × D(ω1) being R-factorizable, and implies several structural properties (hereditarily Lindelöf and hereditarily separable; second-countable if w(X) ≤ ω1). The authors also show that the existence of nonmetrizable Rω1-factorizable spaces is consistent with ZFC under certain set-theoretic assumptions.

Despite these strong constraints, it remains unclear if Rω1-factorizability forces a space to be cosmic (i.e., to have a countable network). Establishing cosmicity would provide a significant structural characterization of Rω1-factorizable spaces beyond Lindelöfness and separability.

References

Although the existence of nonmetrizable R"1-factorizable spaces is consistent with ZFC, the following problem remains open. Problem 6.1. Is it true that any R"1-factorizable space is cosmic, that is, has a countable network?

$\mathbb R^{ω_1}$-Factorizable Spaces and Groups (2509.05105 - Lipin et al., 5 Sep 2025) in Section 6 (Open Problems), Problem 6.1