activity
20242026
collaborators
Showing math.GRShow all

8 papers · 1 filter

math.GR2026

Hyperbolicity and obstructions to PL actions of the circle

Leonardo Dinamarca, Maximiliano Escayola, Sang-hyun Kim +1

We investigate acylindrically hyperbolic groups acting on the circle by piecewise linear homeomorphisms. We prove that a finitely generated acylindrically hyperbolic group acting f…

math.GR2026

Linearity criteria for automorphism groups of malabelian groups

Thomas Koberda, Mark Pengitore

Let be a finitely generated malabelian group, let be a finitely generated subgroup, and let denote the preimage of in . W…

math.GR2026

Elementary equivalence and diffeomorphism groups of smooth manifolds

Sang-hyun Kim, Thomas Koberda, J. de la Nuez González

Let and be smooth manifolds, with closed and connected. If the --diffeomorphism group of is elementarily equivalent to the --diffeomorphism group of f…

math.GR2025

Generic torsion-free groups and Rubin actions

Thomas Koberda, Yash Lodha

We use model theoretic forcing to prove that a generic countable torsion-free group does not admit any nontrivial locally moving action on a Hausdorff topological space, and yet ad…

math.GR2025

Uniform first order interpretation of the second order theory of countable groups of homeomorphisms

Thomas Koberda, J. de la Nuez González

We show that the first order theory of the homeomorphism group of a compact manifold interprets the full second order theory of countable groups of homeomorphisms of the manifold.…

math.GR2025

First order rigidity of homeomorphism groups of manifolds

Sang-hyun Kim, Thomas Koberda, J. de la Nuez González

For every compact, connected manifold , we prove the existence of a sentence in the language of groups such that the homeomorphism group of another compact manifold s…