Coherent Ultrafilters and Nonhomogeneity

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21240%2F15%3A00231105" target="_blank" >RIV/68407700:21240/15:00231105 - isvavai.cz</a>

Result on the web

<a href="http://arxiv.org/abs/1404.3703" target="_blank" >http://arxiv.org/abs/1404.3703</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.14712/1213-7243.2015.123" target="_blank" >10.14712/1213-7243.2015.123</a>

Result language

angličtina

Original language name

Coherent Ultrafilters and Nonhomogeneity

Original language description

We introduce the notion of a coherent P-ultrafilter on a complete ccc Boolean algebra, strengthening the notion of a P-point on the set of natural numbers, and show that these ultrafilters exist generically under the assumption that the dominating numberis not less than the continuum. This improves the known existence result of Ketonen. Similarly, the existence theorem of Canjar can be extended to show that coherently selective ultrafilters exist generically under c = cov(meager). We use these ultrafilters in a topological application: a coherent P-ultrafilter on an algebra B is an untouchable point in the Stone space of B, witnessing its nonhomogeneity.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BA - General mathematics

OECD FORD branch

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Project

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Continuities

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Publication year

2015

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Commentationes Mathematicae Universitatis Carolinae

ISSN

0010-2628

e-ISSN

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Volume of the periodical

56

Issue of the periodical within the volume

2

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

8

Pages from-to

257-264

UT code for WoS article

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EID of the result in the Scopus database

2-s2.0-84929153811