# A small ultrafilter number at smaller cardinals

**Authors:** Dilip Raghavan, Saharon Shelah

arXiv: 1904.02379 · 2019-04-05

## TL;DR

This paper demonstrates the consistency of the existence of ultrafilters on certain uncountable sets generated by fewer sets than the maximum, relative to large cardinal assumptions.

## Contribution

It establishes the relative consistency of small ultrafilter numbers at smaller uncountable cardinals using large cardinal hypotheses.

## Key findings

- Existence of a uniform ultrafilter on the reals generated by fewer than continuum sets
- Existence of a uniform ultrafilter on ${m 
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- Consistency results relative to measurable and supercompact cardinals

## Abstract

It is proved to be consistent relative to a measurable cardinal that there is a uniform ultrafilter on the real numbers which is generated by fewer than the maximum possible number of sets. It is also shown to be consistent relative to a supercompact cardinal that there is a uniform ultrafilter on ${\aleph}_{\omega+1}$ which is generated by fewer than ${2}^{{\aleph}_{\omega+1}}$ sets.

## Full text

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## References

10 references — full list in the complete paper: https://tomesphere.com/paper/1904.02379/full.md

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Source: https://tomesphere.com/paper/1904.02379