Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-20T03:57:05.243Z Has data issue: false hasContentIssue false

ONE-DIMENSIONAL SUBGROUPS AND CONNECTED COMPONENTS IN NON-ABELIAN p-ADIC DEFINABLE GROUPS

Published online by Cambridge University Press:  29 April 2024

WILLIAM JOHNSON*
Affiliation:
SCHOOL OF PHILOSOPHY FUDAN UNIVERSITY 220 HANDAN ROAD GUANGHUA WEST BUILDING ROOM 2503 SHANGHAI 200433 CHINA E-mail: yaony@fudan.edu.cn
NINGYUAN YAO
Affiliation:
SCHOOL OF PHILOSOPHY FUDAN UNIVERSITY 220 HANDAN ROAD GUANGHUA WEST BUILDING ROOM 2503 SHANGHAI 200433 CHINA E-mail: yaony@fudan.edu.cn

Abstract

We generalize two of our previous results on abelian definable groups in p-adically closed fields [12, 13] to the non-abelian case. First, we show that if G is a definable group that is not definably compact, then G has a one-dimensional definable subgroup which is not definably compact. This is a p-adic analogue of the Peterzil–Steinhorn theorem for o-minimal theories [16]. Second, we show that if G is a group definable over the standard model $\mathbb {Q}_p$, then $G^0 = G^{00}$. As an application, definably amenable groups over $\mathbb {Q}_p$ are open subgroups of algebraic groups, up to finite factors. We also prove that $G^0 = G^{00}$ when G is a definable subgroup of a linear algebraic group, over any model.

MSC classification

Type
Article
Copyright
© The Author(s), 2024. Published by Cambridge University Press on behalf of The Association for Symbolic Logic

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

Acosta López, J. P., One dimensional groups definable in the $p$ -adic numbers . Journal of Symbolic Logic , vol. 86 (2021), no. 2, pp. 801816.CrossRefGoogle Scholar
Andújar Guerrero, P. and Johnson, W., Around definable types in $p$ -adically closed fields, preprint, 2022, arXiv:2208.05815v1 [math.LO].CrossRefGoogle Scholar
Cluckers, R., Presburger sets and P-minimal fields . Journal of Symbolic Logic , vol. 68 (2003), no. 1, pp. 153162.CrossRefGoogle Scholar
Cubides-Kovacsics, P., Darnière, L., and Leenknegt, E., Topological cell decomposition and dimension theory in $P$ -minimal fields . Journal of Symbolic Logic , vol. 82 (2017), no. 1, pp. 347358.CrossRefGoogle Scholar
van den Dries, L., Classical model theory of fields , Model Theory, Algebra, and Geometry (Haskell, D., Pillay, A., and Steinhorn, C., editors), Mathematical Sciences Research Institute Publications, 39, Cambridge University Press, Cambridge, 2000, pp. 3752.Google Scholar
van den Dries, L., Haskell, D., and Macpherson, D., One dimensional $p$ -adic subanalytic sets . Journal of the London Mathematical Society , vol. 59 (1999), no. 1, pp. 120.CrossRefGoogle Scholar
Hofmann, K. H. and Morris, S. A., The Structure of Compact Groups , De Gruyter Studies in Mathematics, 25, de Gruyter, Berlin, 2013.CrossRefGoogle Scholar
Hrushovski, E. and Pillay, A., Groups definable in local and pseudofinite fields . Israel Journal of Mathematics , vol. 85 (1994), pp. 203262.CrossRefGoogle Scholar
Johnson, W., Interpretable sets in dense o-minimal structures . Journal of Symbolic Logic , vol. 83 (2018), pp. 14771500.CrossRefGoogle Scholar
Johnson, W., On the proof of elimination of imaginaries in algebraically closed valued fields . Notre Dame Journal of Formal Logic , vol. 61 (2020), no. 3, pp. 363381.CrossRefGoogle Scholar
Johnson, W., Topologizing interpretable groups in $p$ -adically closed fields . Notre Dame Journal of Formal Logic , to appear, 2024.Google Scholar
Johnson, W. and Yao, N., On non-compact $p$ -adic definable groups . Journal of Symbolic Logic , vol. 87 (2022), no. 1, pp. 188213.CrossRefGoogle Scholar
Johnson, W. and Yao, N., Abelian groups definable in $p$ -adically closed fields . Journal of Symbolic Logic , published online, 2023.CrossRefGoogle Scholar
Milne, J. S., Algebraic Groups: The Theory of Group Schemes of Finite Type over a Field , Cambridge Studies in Advanced Mathematics, 170, Cambridge University Press, Cambridge, 2017.CrossRefGoogle Scholar
Onshuus, A. and Pillay, A., Definable groups and compact $p$ -adic Lie groups . Journal of the London Mathematical Society , vol. 78 (2008), no. 1, pp. 233247.CrossRefGoogle Scholar
Peterzil, Y. and Steinhorn, C., Definable compactness and definable subgroups of o-minimal groups . Journal of the London Mathematical Society , vol. 59 (1999), no. 3, pp. 769786.CrossRefGoogle Scholar
Pillay, A., On fields definable in ${\mathbb{Q}}_p$ . Archive for Mathematical Logic , vol. 29 (1989), pp. 17.CrossRefGoogle Scholar
Pillay, A., Model theory of algebraically closed fields , Model Theory and Algebraic Geometry (Bouscaren, E., editor), Lecture Notes in Mathematics, 1696, Springer Berlin, Heidelberg, 1998, pp. 6184.CrossRefGoogle Scholar
Pillay, A. and Yao, N., A note on groups definable in the $p$ -adic field . Archive for Mathematical Logic , vol. 58 (2019), pp. 10291034.CrossRefGoogle Scholar
Platonov, V. and Rapinchuk, A., Algebraic Groups and Number Theory , Academic Press, San Diego, 1994.Google Scholar
Schneider, P., p-Adic Lie Groups , Grundlehren der mathematischen Wissenschaften, 344, Springer, Berlin, 2011.CrossRefGoogle Scholar
Simon, P., A Guide to NIP Theories , Lecture Notes in Logic, Cambridge University Press, Cambridge, 2015.CrossRefGoogle Scholar