Groups, measures, and the NIP

E Hrushovski, Y Peterzil, A Pillay - Journal of the American Mathematical …, 2008 - ams.org
We discuss measures, invariant measures on definable groups, and genericity, often in an
NIP (failure of the independence property) environment. We complete the proof of the third …

On NIP and invariant measures

E Hrushovski, A Pillay - Journal of the European Mathematical …, 2011 - content.ems.press
We study forking, Lascar strong types, Keisler measures and definable groups, under an
assumption of NIP (not the independence property), continuing aspects of the paper [16] …

Type-definability, compact Lie groups, and o-minimality

A Pillay - Journal of Mathematical Logic, 2004 - World Scientific
We study type-definable subgroups of small index in definable groups, and the structure on
the quotient, in first order structures. We raise some conjectures in the case where the …

Topological dynamics of definable group actions

L Newelski - The Journal of Symbolic Logic, 2009 - cambridge.org
TOPOLOGICAL DYNAMICS OF DEFINABLE GROUP ACTIONS Introduction. Assume G is a
group. By a G-flow we mean a compact topological spa Page 1 THE JOURNAL OF SYMBOLIC …

Valued fields, metastable groups

E Hrushovski, S Rideau-Kikuchi - Selecta Mathematica, 2019 - Springer
We introduce a class of theories called metastable, including the theory of algebraically
closed valued fields (ACVF ACVF) as a motivating example. The key local notion is that of …

[HTML][HTML] Connected components of definable groups and o-minimality I

A Conversano, A Pillay - Advances in Mathematics, 2012 - Elsevier
We give examples of definable groups G (in a saturated model, sometimes o-minimal) such
that G00≠ G000, yielding also new examples of “non G-compact” theories. We also prove …

Definable versions of theorems by Kirszbraun and Helly

M Aschenbrenner, A Fischer - Proceedings of the London …, 2011 - academic.oup.com
Kirszbraun's theorem states that every Lipschitz map S→ ℝ n, where S⊆ ℝ m, has an
extension to a Lipschitz map ℝ m→ ℝ n with the same Lipschitz constant. Its proof relies on …

Definable groups and compact p-adic Lie groups

A Onshuus, A Pillay - Journal of the London Mathematical …, 2008 - academic.oup.com
We formulate p-adic analogues of the o-minimal group conjectures from the works of
Hrushovski, Peterzil and Pillay [J. Amer. Math. Soc., to appear] and Pillay [J. Math. Log. 4 …

On central extensions and definably compact groups in o-minimal structures

E Hrushovski, Y Peterzil, A Pillay - Journal of Algebra, 2011 - Elsevier
We prove several structural results on definable, definably compact groups G in o-minimal
expansions of real closed fields such as (i) G is definably an almost direct product of a …

Groups definable in ordered vector spaces over ordered division rings

PE Eleftheriou, S Starchenko - The Journal of Symbolic Logic, 2007 - cambridge.org
Let M=< M,+,<, 0,{λ} λЄD> be an ordered vector space over an ordered division ring D, and
G=< G,⊕, eG> an n-dimensional group definable in M. We show that if G is definably …