English
Related papers

Related papers: Automatic continuity for homomorphisms into free p…

200 papers

We show that any homomorphism from the homeomorphism group of a compact 2-manifold, with the compact-open topology, or equivalently, with the topology of uniform convergence, into a separable topological group is automatically continuous.

Geometric Topology · Mathematics 2007-05-23 Christian Rosendal

A group $G$ is called automatically continuous if any homomorphism from a completely metrizable or locally compact Hausdorff group to $G$ has open kernel. In this paper, we study preservation of automatic continuity under group-theoretic…

Group Theory · Mathematics 2020-10-07 Samuel M. Corson , Ilya Kazachkov

It was proved that for any finite set of elements of a free product of residually finite groups such that no two of them belong to conjugate cyclic subgroups and each of them do not belong to a subgroup which is conjugate a to free factor…

Group Theory · Mathematics 2010-11-04 Vladimir V. Yedynak

We show that every homomorphism from the infinite-dimensional unitary or orthogonal group to a separable group is continuous.

Functional Analysis · Mathematics 2011-09-07 Todor Tsankov

The homology groups of the automorphism group of a free group are known to stabilize as the number of generators of the free group goes to infinity, and this paper relativizes this result to a family of groups that can be defined in terms…

Geometric Topology · Mathematics 2014-11-11 Allen Hatcher , Nathalie Wahl

We prove that arbitrary homomorphisms from one of the groups ${\rm Homeo}(\ca)$, ${\rm Homeo}(\ca)^\N$, ${\rm Aut}(\Q,<)$, ${\rm Homeo}(\R)$, or ${\rm Homeo}(S^1)$ into a separable group are automatically continuous. This has consequences…

Logic · Mathematics 2007-05-23 Christian Rosendal , Slawomir Solecki

We define a free product of connected simple graphs that is equivalent to several existing definitions when the graphs are vertex-transitive but differs otherwise. The new definition is designed for the automorphism group of the free…

Group Theory · Mathematics 2021-09-30 Max Carter , Stephan Tornier , George A. Willis

Let M be a compact manifold, possibly with boundary. We show that the group of homeomorphisms of M has the automatic continuity property: any homomorphism from Homeo(M) to any separable group is necessarily continuous. This answers a…

Geometric Topology · Mathematics 2016-10-19 Kathryn Mann

We extend the proof of automatic continuity for homeomorphism groups of manifolds to non-compact manifolds and manifolds with marked points and their mapping class groups. Specifically, we show that, for any manifold $M$ homeomorphic to the…

Geometric Topology · Mathematics 2020-03-04 Kathryn Mann

It is shown that the big free group (the set of countably-long words over a countable alphabet) is almost free, in the sense that any function from the alphabet to a compact topological group factors through a homomorphism. This statement…

Group Theory · Mathematics 2015-06-12 Tamer Tlas

In this note we prove that a homomorphism from a compact connected simple Lie group with the norm topology to any separable SIN group is automatically continuous. This generalizes a result by Dowerk and Thom. Further, we prove some…

Group Theory · Mathematics 2018-11-13 Laurens Diels , Philip A. Dowerk

We show that every abstract homomorphism $\varphi$ from a locally compact group $L$ to a graph product $G_\Gamma$, endowed with the discrete topology, is either continuous or $\varphi(L)$ lies in a 'small' parabolic subgroup. In particular,…

Group Theory · Mathematics 2019-08-14 Linus Kramer , Olga Varghese

We present new results regarding automatic continuity, unifying some diagonalization concepts that have been developed over the years. For example, any homomorphism from a completely metrizable topological group to Thompson's group $F$ has…

Group Theory · Mathematics 2019-08-13 Gregory R. Conner , Samuel M. Corson

If $N \subset \R$ is a separable II$_1$-factor, the space $\Hom(N,\R)$ of unitary equivalence classes of unital *-homomorphisms $N \to \R$ is shown to have a surprisingly rich structure. If $N$ is not hyperfinite, $\Hom(N,\R)$ is an…

Operator Algebras · Mathematics 2011-12-08 Nathanial P. Brown

A general overview of the phenomenon of automatic continuity of homomorphisms between Polish groups is given. In particular, we study variants and improvements of the closed graph theorem, applying these to the problem of continuity of…

Group Theory · Mathematics 2025-09-16 Christian Rosendal , Luis Carlos Suarez

A continuous family of non-outer conjugate aperiodic automorphisms whose crossed-products are all isomorphic is given on every interpolated free group factor. An explicit "duality" relationship between compact co-commutative Kac algebra…

Operator Algebras · Mathematics 2019-05-21 Fumio Hiai , Yoshimichi Ueda

We examine the completely isometric automorphisms of a free product of noncommutative disc algebras. It will be established that such an automorphism is given simply by a completely isometric automorphism of each component of the free…

Operator Algebras · Mathematics 2015-07-01 Christopher Ramsey

We consider a few types of bounded homomorphisms on a topological group. These classes of bounded homomorphisms are, in a sense, weaker than the class of continuous homomorphisms. We show that with appropriate topologies each class of these…

General Topology · Mathematics 2015-08-25 Ljubisa D. R. Kocinac , Omid Zabeti

We improve on earlier results on the closure under free products of the class of automaton semigroups. We consider partial automata and show that the free product of two self-similar semigroups (or automaton semigroups) is self-similar (an…

Group Theory · Mathematics 2025-09-01 Tara Macalister Brough , Jan Philipp Wächter , Janette Welker

In this article, we show that the stabilized automorphism group of free exact odometers arising from actions of finitely generated residually finite groups coincides with the topological full group of the odometer acting on itself by right…

Group Theory · Mathematics 2026-01-13 María Isabel Cortez , Vicente Urria
‹ Prev 1 2 3 10 Next ›