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EQUIVALENCE RELATIONS INVARIANT UNDER GROUP ACTIONS

Published online by Cambridge University Press:  01 August 2018

TOMASZ RZEPECKI
TOMASZ RZEPECKI*
Affiliation:
INSTYTUT MATEMATYCZNY UNIWERSYTET WROCŁAWSKI PL. GRUNWALDZKI 2/4 50-384 WROCŁAW, POLANDE-mail:tomasz.rzepecki@math.uni.wroc.pl
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Abstract

We extend some recent results about bounded invariant equivalence relations and invariant subgroups of definable groups: we show that type-definability and smoothness are equivalent conditions in a wider class of relations than heretofore considered, which includes all the cases for which the equivalence was proved before.

As a by-product, we show some analogous results in purely topological context (without direct use of model theory).

Keywords

03C4503E1554H1522C05bounded invariant equivalence relationsBorel cardinalitytransformation groupsequivalence relationscompact groups
Type
Articles
Information
The Journal of Symbolic Logic , Volume 83 , Issue 2 , June 2018 , pp. 683 - 702
Copyright
Copyright © The Association for Symbolic Logic 2018 

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References

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