Definably amenable NIP groups
Year: 2015
Type: preprint
Abstract: We study definably amenable NIP groups. We develop a theory of generics, showing that various definitions considered previously coincide, and study invariant measures. Applications include: characterization of regular ergodic measures, a proof of the conjecture of Petrykowski connecting existence of bounded orbits with definable amenability in the NIP case, and the Ellis group conjecture of Newelski and Pillay connecting the model-theoretic connected component of an NIP group with the ideal subgroup of its Ellis enveloping semigroup.
Source: arXiv (Cornell University)
Authors: Chernikov, Artem, Simon, Pierre
Language: English
Subfield: Geometry and Topology
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
Awards: G1135293650, Model Theory of Unstable Structures, G3207356259, G3498229676, G3602381172, G3633247507, G393177772, Model-Theoretic Classification, Graph Combinatorics, and Topological Dynamics, G4104599821, G459516591, G5702163051, G609738274, Valuations, Combinatorics and Model Theory, G7240651115, Fondation Sciences Mathématiques de Paris, G7376787254, CAREER: Model theory, measures and combinatorics
OpenAlex ID: W4290754530
