Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-20T00:47:12.922Z Has data issue: false hasContentIssue false

DEFINABLE AND INVARIANT TYPES IN ENRICHMENTS OF NIP THEORIES

Published online by Cambridge University Press:  21 March 2017

SILVAIN RIDEAU
Affiliation:
UNIVERSITY OF CALIFORNIA, BERKELEY MATHEMATICS DEPARTMENT, EVANS HALL BERKELEY, CA, 94720-3840, USAE-mail: silvain.rideau@berkeley.eu
PIERRE SIMON
Affiliation:
UNIV LYON, UNIVERSITÉ CLAUDE BERNARD LYON 1 CNRS UMR 5208, INSTITUT CAMILLE JORDAN 43 BLVD. DU 11 NOVEMBRE 1918 F-69622 VILLEURBANNE CEDEX, FRANCEE-mail: simon@math.univ-lyon1.fr

Abstract

Let T be an NIP ${\cal L}$-theory and $\mathop T\limits^\~ $ be an enrichment. We give a sufficient condition on $\mathop T\limits^\~$ for the underlying ${\cal L}$-type of any definable (respectively invariant) type over a model of $\mathop T\limits^\~$ to be definable (respectively invariant). These results are then applied to Scanlon’s model completion of valued differential fields.

Type
Articles
Copyright
Copyright © The Association for Symbolic Logic 2017 

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

Haskell, D., Hrushovski, E., and Macpherson, D., Definable sets in algebraically closed valued fields: elimination of imaginaries . Journal für die Reine und Angewandte Mathematik (Crelles Journal), vol. 597 (2006), pp. 175236.Google Scholar
Hrushovski, E. and Pillay, A., On NIP and invariant measures . Journal of the European Mathematical Society, vol. 13 (2011), no. 4, pp. 10051061.Google Scholar
Matoušek, J., Bounded VC-dimension implies a fractional Helly theorem . Discrete and Computational Geometry, vol. 31 (2004), no. 2, pp. 251255.CrossRefGoogle Scholar
Rideau, S., Imaginaries in valued differential fields , Journal für die Reine und Angewandte Mathematik (CrellesJournal), to appear.Google Scholar
Scanlon, T., A model complete theory of valued D-fields, this JOURNAL, vol. 65 (2000),no. 4, pp. 17581784.Google Scholar
Simon, P., A Guide to NIP Theories. Lecture Notes in Logic, vol. 44, Cambridge University Press, Cambridge, Association of Symbolic Logic, Chicago, IL, 2015.Google Scholar
Simon, P., Invariant types in NIP theories . Journal of Mathematical Logic, vol. 15 (2015), no. 2.Google Scholar