English

Reasonable ultrafilters, again

Logic 2013-01-04 v2

Abstract

We continue investigations of reasonable ultrafilters on uncountable cardinals defined in math.LO/0407498. We introduce stronger properties of ultrafilters and we show that those properties may be handled in lambda-support iterations of reasonably bounding forcing notions. We use this to show that consistently there are reasonable ultrafilters on an inaccessible cardinal lambda with generating system of size less than 2^lambda . We also show how reasonable ultrafilters can be killed by forcing notions which have enough reasonable completeness to be iterated with lambda-supports (and we show the appropriate preservation theorem).

Keywords

Cite

@article{arxiv.math/0605067,
  title  = {Reasonable ultrafilters, again},
  author = {Andrzej Roslanowski and Saharon Shelah},
  journal= {arXiv preprint arXiv:math/0605067},
  year   = {2013}
}