MODNET
Research Training Network in Model Theory
Publications > Preprint server > Preprint Number 440

Preprint Number 440

Previous Next Preprint server


440. Krzysztof Krupinski, Anand Pillay and Slawomir Solecki
Borel equivalence relations and Lascar strong types
E-mail:

Submission date: 17 April 2012.

Abstract:

The space of Lascar strong types, on some sort and relative to a given first order theory T, is in general not a compact Hausdorff space. This paper has at least three aims. First to show that spaces of Lascar strong types and other related spaces such as the Lascar group, have well-defined Borel cardinalities. The second is to compute the Borel cardinalities of the known examples as well as some new examples. The third is to explore notions of definable map, embedding and isomorphism between these and related quotient objects. The motivation for writing this paper is the recent discovery, via definable groups, of new examples of non G-compact first order theories.

Mathematics Subject Classification: 03C45

Keywords and phrases:

Full text arXiv 1204.3485: pdf, ps.


Last updated: April 25 2012 14:18 Please send your corrections to: