The spectrum of characters of ultrafilters on ω

Saharon Shelah. "The spectrum of characters of ultrafilters on ω." Colloquium Mathematicae 111.2 (2008): 213-220. <http://eudml.org/doc/283906>.

@article{SaharonShelah2008,
abstract = {We show the consistency of the statement: "the set of regular cardinals which are the characters of ultrafilters on ω is not convex". We also deal with the set of π-characters of ultrafilters on ω.},
author = {Saharon Shelah},
journal = {Colloquium Mathematicae},
keywords = {characters; ultrafilter; forcing},
language = {eng},
number = {2},
pages = {213-220},
title = {The spectrum of characters of ultrafilters on ω},
url = {http://eudml.org/doc/283906},
volume = {111},
year = {2008},
}

TY - JOUR
AU - Saharon Shelah
TI - The spectrum of characters of ultrafilters on ω
JO - Colloquium Mathematicae
PY - 2008
VL - 111
IS - 2
SP - 213
EP - 220
AB - We show the consistency of the statement: "the set of regular cardinals which are the characters of ultrafilters on ω is not convex". We also deal with the set of π-characters of ultrafilters on ω.
LA - eng
KW - characters; ultrafilter; forcing
UR - http://eudml.org/doc/283906
ER -