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Related papers: Amenable category and complexity

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Let A be a Banach algebra and I be a closed ideal of A. We say that A is amenable relative to I, if A/I is an amenable Banach algebra. We study the relative amenability of Banach algebras and investigate the relative amenability of…

Functional Analysis · Mathematics 2019-12-02 Hoger Ghahramani , Wania Khodakarami , Esmaeil Feizi

We investigate an analogue of the L^2-Betti numbers for amenable linear subshifts. The role of the von Neumann dimension shall be played by the topological entropy.

Dynamical Systems · Mathematics 2007-05-23 Gabor Elek

In this paper we address the question: How many pairwise non-isomorphic extremely amenable groups are there which are separable metrizable or even Polish? We show that there are continuum many such groups. In fact we construct continuum…

Logic · Mathematics 2026-03-23 Mahmood Etedadialiabadi , Su Gao , Feng Li , Ruiwen Li

In this paper we extend the approach of M. Cavaleri to effective amenability to the class of computably enumerable groups, i.e. in particular we do not assume that groups are finitely generated. In the case of computable groups we also…

Group Theory · Mathematics 2022-05-16 Karol Duda

We introduce a notion of complexity of diagrams (and in particular of objects and morphisms) in an arbitrary category, as well as a notion of complexity of functors between categories equipped with complexity functions. We discuss several…

Category Theory · Mathematics 2020-07-01 Saugata Basu , M. Umut Isik

We analyse omega-categorical precompact expansions of particular omega-categorical structures from the viewpoint of amenability of their automorphism groups. The main result of the paper corrects and simplifies Section 3.2 of the first…

Logic · Mathematics 2017-01-27 A. Ivanov

We show that for a Banach algebra $A$ with a bounded approximate identity, the amenability of the projective tensor product of A with A, the amenability of the projective tensor product of A with A^{op}and the amenability of A are…

Functional Analysis · Mathematics 2010-12-08 Miad Makareh Shireh

By giving an interesting characterisation of amenable multiplicative unitaries in term of one dimensional representations, we show in a simple way that bicrossproducts of amenable locally compact groups is both amenable and coamenable.

Operator Algebras · Mathematics 2007-05-23 Chi-Keung Ng

We establish that a second countable locally compact groupoid possessing a continuous Haar system is topologically amenable if and only if it is Borel amenable. We give some examples and applications.

Dynamical Systems · Mathematics 2013-04-09 Jean Renault

In the present paper, the concepts of module (uniform) approximate amenability and contractibility of Banach algebras that are modules over another Banach algebra, are introduced. The general theory is developed and some hereditary…

Functional Analysis · Mathematics 2013-01-16 Hasan Pourmahmood-Aghababa , Abasalt Bodaghi

We first study the higher version of the relative topological complexity by using the homotopic distance. We also introduced the generalized version of the relative topological complexity of a topological pair on both the Schwarz genus and…

Algebraic Topology · Mathematics 2022-03-07 Melih İs , İsmet Karaca

We introduce a topology on the space of all isomorphism types represented in a given class of countable models, and use this topology as an aid in classifying the isomorphism types. This mixes ideas from effective descriptive set theory and…

Logic · Mathematics 2019-08-20 Russell Miller

We study the automorphism groups of countable homogeneous directed graphs (and some additional homogeneous structures) from the point of view of topological dynamics. We determine precisely which of these automorphism groups are amenable…

Combinatorics · Mathematics 2017-12-29 Micheal Pawliuk , Miodrag Sokic

In this paper we study unimodular amenable groups. The first part is devoted to results on the existence of uniform families of epsilon-quasi tilings for these groups. In this context, constructions of Ornstein and Weiss are extended by…

Spectral Theory · Mathematics 2013-07-31 Felix Pogorzelski , Fabian Schwarzenberger

A topological group $G$ is extremely amenable if every continuous action of $G$ on a compact space has a fixed point. Using the concentration of measure techniques developed by Gromov and Milman, we prove that the group of automorphisms of…

Group Theory · Mathematics 2007-09-03 Thierry Giordano , Vladimir Pestov

We define a new version of Topological Complexity (TC) of a space, denoted as $\text{dTC}$, which, we think, fits better for motion planning for some autonomous systems. Like Topological complexity, \text{dTC} is also a homotopy invariant.…

Geometric Topology · Mathematics 2024-09-09 Alexander Dranishnikov , Ekansh Jauhari

In this paper we study analogues of amenability for topological groups in the context of definable structures. We prove fixed point theorems for such groups. More importantly, we propose definitions for definable actions and continuous…

Logic · Mathematics 2018-12-14 Alf Onshuus , Luis Carlos Suárez

We consider three (2-)categories and their (anti-)equivalence. They are the category of small abelian categories and exact functors, the category of definable additive categories and interpretation functors, the category of locally coherent…

Category Theory · Mathematics 2012-02-03 Mike Prest

We determine the Lusternik-Schnirelmann category of the projective product spaces introduced by D. Davis. We also obtained an upper bound for the topological complexity of these spaces, which improves the estimate given by J. Gonz\'alez, M.…

Algebraic Topology · Mathematics 2020-12-10 Seher Fişekci , Lucile Vandembroucq

By classifying $S$-maximal amenable subgroups of algebraic groups over a global field of characteristic zero, we obtain a complete classification of maximal amenable subgroups up to commensurability in the respective arithmetic groups.…

Group Theory · Mathematics 2022-10-21 Vadim Alekseev , Alessandro Carderi