Pseudofinite groups and VC-dimension
Preprint
Abstract
We develop local NIP group theory in the context of pseudofinite groups. In particular, given a sufficiently saturated pseudofinite structure $G$ expanding a group, and left invariant NIP formula $\delta(x;\bar{y})$, we prove various aspects of "local fsg" for the right-stratified formula $\delta^r(x;\bar{y},u):=\delta(x\cdot u;\bar{y})$. This includes a $\delta^r$-type-definable connected component, uniqueness of the pseudofinite counting measure as a left-invariant measure on $\delta^r$-formulas, and generic compact domination for $\delta^r$-definable sets.
Keywords
All Related Versions
This publication has 9 references indexed in Scilit:
- A group version of stable regularityMathematical Proceedings of the Cambridge Philosophical Society, 2018
- Definably amenable NIP groupsJournal of the American Mathematical Society, 2018
- Rosenthal compacta and NIP formulasFundamenta Mathematicae, 2015
- Generically stable and smooth measures in NIP theoriesTransactions of the American Mathematical Society, 2012
- Topological dynamics of definable group actionsThe Journal of Symbolic Logic, 2009
- TYPE-DEFINABILITY, COMPACT LIE GROUPS, AND o-MINIMALITYJournal of Mathematical Logic, 2004
- Groups definable in local fields and pseudo-finite fieldsIsrael Journal of Mathematics, 1994
- Almost tight bounds forɛ-NetsDiscrete & Computational Geometry, 1992
- ɛ-nets and simplex range queriesDiscrete & Computational Geometry, 1987