Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-10T13:23:14.309Z Has data issue: false hasContentIssue false

On PAC and bounded substructures of a stable structure

Published online by Cambridge University Press:  12 March 2014

Anand Pillay
Affiliation:
School of Mathematics, University of Leeds, Leeds LS2 9JT, UK. E-mail: pillay@maths.leeds.ac.uk
Dominika Polkowska
Affiliation:
St. Cecilia Novitiate, 801 Dominion Drive, Nashville, TN 37228, USA

Abstract

We introduce and study the notions of a PAC-substructure of a stable structure, and a bounded substructure of an arbitrary substructure, generalizing [10]. We give precise definitions and equivalences, saying what it means for properties such as PAC to be first order, study some examples (such as differentially closed fields) in detail, relate the material to generic automorphisms, and generalize a “descent theorem” for pseudo-algebraically closed fields to the stable context. We also point out that the elementary invariants of pseudo-algebraically closed fields from [6] are also valid for pseudo-differentially closed fields.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Ax, J., The elementary theory of finite fields, Annals of Mathematics, vol. 88 (1967), pp. 239271.CrossRefGoogle Scholar
[2]Baldwin, J. and Shelah, S., Model companions of Taut for stable T, Notre Dame Journal of Formal Logic, vol. 42 (2001), pp. 129142.CrossRefGoogle Scholar
[3]Chatzidakis, Z., Properties of forking in ω-free pseudo-algebraically closed fields, this Journal, vol. 67 (2002), pp. 957996.Google Scholar
[4]Chatzidakis, Z., van den Dries, L., and Macintyre, A.. Definable sets over finite fields. Journal für die Reine und Angewandte Mathematik, vol. 427 (1992), pp. 107135.Google Scholar
[5]Chatzidakis, Z. and Pillay, A., Generic structures and simple theories, Annals of Pure and Applied Logic, vol. 95 (1998), pp. 7192.CrossRefGoogle Scholar
[6]Cherlin, G., van den Dries, L., and Macintyre, A.. The elementary theory of regularly closed fields, preprint. 1980.Google Scholar
[7]Cherlin, G., van den Dries, L., Decidability and undecidability theorems for PAC-fields, American Mathematical Society, Bulletin, vol. 4 (1981), pp. 101104.CrossRefGoogle Scholar
[8]Fried, M. and Jarden, M., Field arithmetic, second ed., Springer, 2005.CrossRefGoogle Scholar
[9]Hasson, A. and Hrushovski, E.. DMP in strongly minimal structures, preprint, 2004.Google Scholar
[10]Hrushovski, E., Pseudofinite fields and related structures, Model theory and applications (Bélair, , Chatzidakis, , D'Aquino, , Otero, , Point, , and Wilkie, , editors), Quaderni di Matematica, vol. 11. Univ. Napoli. 2003.Google Scholar
[11]Kikyo, H. and Pillay, A.. The definable multiplicity property and generic automorphisms. Annals of Pure and Applied Logic, vol. 106 (2000), pp. 263273.CrossRefGoogle Scholar
[12]Kim, B., Forking in simple unstable theories, The Journal of the London Mathematical Society, vol. 57 (1998), pp. 257267.CrossRefGoogle Scholar
[13]Kim, B. and Pillay, A.. Simple theories, Annals of Pure and Applied Logic, vol. 88 (1997), pp. 149164.CrossRefGoogle Scholar
[14]Kudaibergenov, K., On generic automorphisms, Mathematical Proceedings. vol. 6 (2003). no. 1. pp. 123.Google Scholar
[15]Marker, D., Model theory of differential fields, The model theory of fields (Marker, , Messmer, , and Pillay, , editors). Lecture Notes in Logic, vol. 5. Springer, 1996.CrossRefGoogle Scholar
[16]Pierce, D., Geometric characterizations of exist entially closed fields with operators, Illinois Journal of Mathematics, vol. 48 (2004), pp. 13211343.CrossRefGoogle Scholar
[17]Pierce, D. and Pillay, A., A note on the axioms for differentially closed fields of characteristic zero, Journal of Algebra, vol. 204 (1998), pp. 108115.CrossRefGoogle Scholar
[18]Pillay, A., Geometric stability theory, Oxford University Press, 1996.CrossRefGoogle Scholar
[19]Pillay, A., Two remarks on differential fields, Model theory and applications (Bélair, , Chatzidakis, , D'Aquino, , Otero, , Point, , and Wilkie, , editors), Quaderni di Matematica, vol. 11. Univ. Napoli. 2003.Google Scholar
[20]Poizat, B., Une théorie de Galois imaginaire, this Journal, vol. 48 (1983), pp. 11511171.Google Scholar
[21]Poizat, B., Paires de structures stables, this Journal, vol. 49 (1984), pp. 239249.Google Scholar
[22]Polkowska, D., On simplicity of bounded pseudo-algebraically closed structures, preprint. 2005.Google Scholar