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Related papers: A note on automatic continuity

200 papers

We prove automatic continuity theorems for "decomposable" or "local" linear transformations between certain natural subspaces of operator algebras. The transformations involved are not algebra homomorphisms but often are module…

Operator Algebras · Mathematics 2017-06-09 Lawrence G. Brown

We consider simplicial complexes that are generated from the binomial random 3-uniform hypergraph by taking the downward-closure. We determine when this simplicial complex is homologically connected, meaning that its zero-th and first…

Combinatorics · Mathematics 2016-04-05 Oliver Cooley , Penny Haxell , Mihyun Kang , Philipp Sprüssel

To any free group automorphism, we associate a universal (cone of) limit tree(s) with three defining properties: first, the tree has a minimal isometric action of the free group with trivial arc stabilizers; second, there is a unique…

Group Theory · Mathematics 2024-12-23 Jean Pierre Mutanguha

We establish a decomposition of stable homology of automorphism groups of free groups with polynomial contravariant coefficients in term of functor homology. This allows several explicit computations, intersecting results obtained by…

Algebraic Topology · Mathematics 2019-08-15 Aurélien Djament

Complementing and extending the Inventiones work of Benson, Grodal, Henke [Group cohomology and control of p-fusion, Invent. Math. 197 (2014), 491--507] we give criteria for a space to have cohomology (strongly) F-isomorphic in the sense of…

Algebraic Topology · Mathematics 2019-01-18 Nora Seeliger

Classical finite association schemes lead to a finite-dimensional algebras which are generated by finitely many stochastic matrices. Moreover, there exist associated finite hypergroups. The notion of classical discrete association schemes…

Group Theory · Mathematics 2019-05-21 Michael Voit

We prove a new automorphy lifting theorem for l-adic representations where we impose a new condition at l, which we call `potential diagonalizability'. This result allows for `change of weight' and seems to be substantially more flexible…

Number Theory · Mathematics 2013-12-10 Thomas Barnet-Lamb , Toby Gee , David Geraghty , Richard Taylor

We give a purely algebraic construction of the continuous closure of any finitely generated torsion free module; a concept first studied by H.~Brenner and M.~Hochster. The construction implies that, at least in characteristic 0, taking…

Commutative Algebra · Mathematics 2010-10-27 János Kollár

By the work of Brodzki-Niblo-Nowak-Wright and Monod, topological amenability of a continuous group action can be characterized using uniformly finite homology groups or bounded cohomology groups associated to this action. We show that…

Dynamical Systems · Mathematics 2021-08-11 Yongle Jiang

Let $\mathcal K$ be a complete quasivariety of completely regular universal topological algebras of continuous signature $\mathcal E$ (which means that $\mathcal K$ is closed under taking subalgebras, Cartesian products, and includes all…

General Topology · Mathematics 2012-02-22 T. Banakh , O. Hryniv

We prove that the generalised word problem of a finitely generated subgroup of a finitely generated virtually free group is context-free, that a hyperbolic group must be virtually free if it has a torsion-free quasiconvex subgroup of…

Group Theory · Mathematics 2015-11-04 Derek F. Holt , Sarah Rees

We study so called weakly-periodic twisted-multiplicative automorphisms of the free skew-field. In particular, we show that any automorphism of a free skew-field that is defined by a periodic automorphism of a free group is equivalent to a…

Group Theory · Mathematics 2023-04-18 Gregor Podlogar

We prove that (a) discrete compact quantum groups (or more generally locally compact, under additional hypotheses) with coamenable dual are continuous fields over their central closed quantum subgroups, and (b) the same holds for free…

Operator Algebras · Mathematics 2020-11-30 Alexandru Chirvasitu

We are concerned with orderable groups and particularly those with orderings invariant not only under multiplication, but also under a given automorphism or family of automorphisms. Several applications to topology are given: we prove that…

Group Theory · Mathematics 2014-10-01 Dale Rolfsen , Bert Wiest

We introduce a geometric invariant, called finite decomposition complexity (FDC), to study topological rigidity of manifolds. We prove for instance that if the fundamental group of a compact aspherical manifold M has FDC, and if N is…

Geometric Topology · Mathematics 2010-08-06 Erik Guentner , Romain Tessera , Guoliang Yu

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 fully irreducible automorphisms of generalized Baumslag-Solitar groups in analogy with fully irreducible automorphisms of free groups. We first obtain a characterization of fully irreducible automorphisms analogous to a condition…

Group Theory · Mathematics 2022-05-19 Chloé Papin

According to the Markus conjecture, closed flat affine manifolds with parallel volume should be complete. We show it is the case for three-manifolds when the holonomy centralizes an affine transformation preserving the volume. It is notably…

Differential Geometry · Mathematics 2023-03-30 Raphaël V Alexandre

We consider the isometry group of the infinite dimensional separable hyperbolic space with its Polish topology. This topology is given by the pointwise convergence. For non-locally compact Polish groups, some striking phenomena like…

Group Theory · Mathematics 2023-05-12 Bruno Duchesne

The Krieger generator theorem says that every invertible ergodic measure-preserving system with finite measure-theoretic entropy can be embedded into a full shift with strictly greater topological entropy. We extend Krieger's theorem to…

Dynamical Systems · Mathematics 2014-06-17 Anthony Quas , Terry Soo