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Do closed-ultrafilter-limits keep cov(N) small?

Determine whether finite-support iterations of ccc forcings whose iterands have closed-ultrafilter-limits (c-uf-limits) can keep the covering number of the null ideal cov(N) small; equivalently, ascertain whether c-uf-limit methods provide the "inside" preservation needed to force C_{[A]^{<θ} ≤_T Cn and thus ensure cov(N) ≤ θ in the resulting model.

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Background

The paper introduces closed-ultrafilter-limits (c-uf-limits) and proves they keep the evasion number e small along suitable iterations. Many left-side invariants in Cichoń's diagram are either below e or above e_ubd, so they are either automatically controlled by keeping e small or are out of reach of c-uf-limits.

The author notes that a plausible remaining candidate on the left side is the covering number of the null ideal cov(N). However, it is not clear whether c-uf-limits can keep this invariant small, and even if they could, existing forcings with c-uf-limits are typically σ-centered or subrandom, which already keep cov(N) small by other means.

References

In the left side of Cicho n's diagram, many cardinal invariants are either below e or above e_{ubd} (hence closed-ultrafilter-limits do not keep them small) and a remaining candidate is N. However, not only it is unclear whether c-uf-limits keep it small, but also even if they did, it would be unclear whether there would be an application since most of the known forcings with c-uf-limits are either σ-centered or sub-random, which keep N small without resorting to c-uf-limits.

Cichoń's maximum with evasion number (2401.14600 - Yamazoe, 26 Jan 2024) in Section 6 (Questions)