The product-space conjecture for D-separability

About 14 years old · traced to

Let XX be a topological space, and let d(X)d(X) denote its density and d(X)+d(X)^+ its successor cardinal. A space is D-separable if every sequence of dense subsets admits a choice of one point from each set such that the set of chosen points is dense.

Product-space conjecture. The space

Xd(X)+X^{d(X)^+}

is never D-separable.

This is presented as an open problem following the theorem that Xω1X^{\omega_1} is not D-separable for every separable space XX with at least two points, and that ds=ω1\mathfrak{ds}=\omega_1. The conjecture asks whether the exponent can generally be reduced to the successor of the density.

References

Primary source

Daniel T. Soukup, Lajos Soukup and Santi Spadaro, “Comparing weak versions of separability”, arXiv:1210.4986 (2012).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.