Abstract
We consider a cardinal invariant closely related to Hindman’s theorem. We prove that this invariant is small in the iterated Sacks perfect set forcing model, and its corresponding parametrized diamond principle implies the existence of union ultrafilters. As a corollary, we obtain the existence of union ultrafilters in the iterated Sacks model of set theory.
Original language | English |
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Pages (from-to) | 261-272 |
Number of pages | 12 |
Journal | Colloquium Mathematicum |
Volume | 153 |
Issue number | 2 |
DOIs | |
State | Published - 2018 |
Externally published | Yes |
Keywords
- Cardinal invariants of the continuum
- Hindman’s theorem
- Iterated Sacks model
- Iterated perfect set forcing
- Parametrized diamond principles
- Union ultrafilters