Weakly Normal Filters and Irregular Ultrafilters

  title={Weakly Normal Filters and Irregular Ultrafilters},
  author={Akihiro Kanamori},
For a filter over a regular cardinal, least functions and the consequent notion of weak normality are described. The following two results, which make a basic connection between the existence of least functions and irregularity of ultrafilters, are then proved: Let U be a uniform ultrafilter over a regular cardinal k. (a) If k = \+, then U is not… CONTINUE READING