Title
A Galois correspondence for countable short recursively saturated models of PA
Abstract
In this paper we investigate the properties of automorphism groups of countable short recursively saturated models of arithmetic. In particular, we show that Kaye's Theorem concerning the closed normal subgroups of automorphism groups of countable recursively saturated models of arithmetic applies to automorphism groups of countable short recursively saturated models as well. That is, the closed normal subgroups of the automorphism group of a countable short recursively saturated model of PA are exactly the stabilizers of the invariant cuts of the model which are closed under exponentiation. This Galois correspondence is used to show that there are countable short recursively saturated models of arithmetic whose automorphism groups are not isomorphic as topological groups. Moreover, we show that the automorphism groups of countable short arithmetically saturated models of PA are not topologically isomorphic to the automorphism groups of countable short recursively saturated models of PA which are not short arithmetically saturated. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Year
DOI
Venue
2010
10.1002/malq.200810050
MATHEMATICAL LOGIC QUARTERLY
Keywords
Field
DocType
Short recursive saturation,automorphism groups,models of PA,Galois correspondence
Saturated model,Discrete mathematics,Combinatorics,Countable set,Automorphism,Isomorphism,Invariant (mathematics),Inner automorphism,Mathematics,Normal subgroup,Topological group
Journal
Volume
Issue
ISSN
56
3
0942-5616
Citations 
PageRank 
References 
0
0.34
9
Authors
1
Name
Order
Citations
PageRank
Erez Shochat131.53