English
Related papers

Related papers: Sparse graphs and the fixed points on type spaces …

200 papers

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

The endomorphism monoid of a model-theoretic structure carries two interesting topologies: on the one hand, the topology of pointwise convergence induced externally by the action of the endomorphisms on the domain via evaluation; on the…

Logic · Mathematics 2026-03-04 Michael Pinsker , Clemens Schindler

In this paper, by establishing a new characterization of the notion of upper semi-continuity of multi-valued mappings in generalized Banach spaces, we prove some Perov type fixed point theorems for multi-valued mappings with closed graphs.…

Functional Analysis · Mathematics 2024-07-22 Khaled Ben Amara , Aref Jeribi , Najib Kaddachi , Zahra Laouar

A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in…

General Topology · Mathematics 2012-09-26 Benjamin Espinoza , Paul Gartside , Merve Kovan-Bakan , Ana Mamatelashvili

The paper studies a general scheme for constructing metrics on a product of metric spaces by means of a family of continuous convex functions. This construction includes the conventional $p$-metrics and generates metrics that are…

Metric Geometry · Mathematics 2026-01-23 Doan Huu Hieu , Vo Minh Tam , Nguyen Duy Cuong

Main results of the paper: (1) For any finite metric space $M$ the Lipschitz free space on $M$ contains a large well-complemented subspace which is close to $\ell_1^n$. (2) Lipschitz free spaces on large classes of recursively defined…

Functional Analysis · Mathematics 2018-07-12 Stephen J. Dilworth , Denka Kutzarova , Mikhail I. Ostrovskii

Structurally stable (rough) flows on surfaces have only finitely many singularities and finitely many closed orbits, all of which are hyperbolic, and they have no trajectories joining saddle points. The violation of the last property leads…

Dynamical Systems · Mathematics 2017-06-07 Vladislav Kruglov , Dmitry Malyshev , Olga Pochinka

In this paper we prove a general theorem showing the extension property for partial automorphisms (EPPA, also called the Hrushovski property) for classes of structures containing relations and unary functions, optionally equipped with a…

Combinatorics · Mathematics 2022-01-25 Jan Hubička , Matěj Konečný , Jaroslav Nešetřil

We study $\omega$-categorical $MS$-measurable structures. Our main result is that a class of $\omega$-categorical Hrushovski constructions, supersimple of finite $SU$-rank is not $MS$-measurable. These results complement the work of Evans…

Logic · Mathematics 2022-11-29 Paolo Marimon

We show that a continuous map or a continuous flow on $\R^{n}$ with a certain recurrence relation must have a fixed point. Specifically, if there is a compact set W with the property that the forward orbit of every point in $\R^{n}$…

Dynamical Systems · Mathematics 2007-05-23 David Richeson , Jim Wiseman

Hierarchically hyperbolic spaces provide a common framework for studying mapping class groups of finite type surfaces, Teichm\"uller space, right-angled Artin groups, and many other cubical groups. Given such a space $\mathcal X$, we build…

Geometric Topology · Mathematics 2018-03-16 Matthew G. Durham , Mark F. Hagen , Alessandro Sisto

We study groups of homeomorphic bijections on spaces that are finite unions of compact connected linearly ordered subsets. We prove that all such groups when endowed with the topology of point-wise convergence are topological groups. }

General Topology · Mathematics 2023-12-29 Raushan Buzyakova

This paper provides a fixed point theorem for asymptotically nonexpansive mappings in uniformly convex hyperbolic spaces as well as new effective results on the Krasnoselski-Mann iterations of such mappings. The latter were found using…

Functional Analysis · Mathematics 2008-03-26 Ulrich Kohlenbach , Laurentiu Leustean

Using a generalization of the Kechris-Pestov-Todor\v{c}evi\'{c} correspondence due to Nguyen Van Th\'{e} we obtain fixed point theorems for null and tame actions of groups of the form $\mathrm{Aut}(\mathcal F)$, where $\mathcal{F}$ is a…

Logic · Mathematics 2025-07-17 Alessandro Codenotti

Configuration spaces of distinct labeled points on the plane are of practical relevance in designing safe control schemes for Automated Guided Vehicles (robots) in industrial settings. In this announcement, we consider the problem of the…

Geometric Topology · Mathematics 2007-05-23 Robert Ghrist

The concept of topological gyrogroups is a generalization of a topological group. In this work, ones prove that a topological gyrogroup G is metrizable iff G has an {\omega}{\omega}-base and G is Frechet-Urysohn. Moreover, in topological…

General Topology · Mathematics 2021-04-27 Meng Bao , Xiaoyuan Zhang , Xiaoquan Xu

In this survey we present a generalization of the notion of metric space and some applications to discrete structures as graphs, ordered sets and transition systems. Results in that direction started in the middle eighties based on the…

Combinatorics · Mathematics 2020-02-11 Mustapha Kabil , Maurice Pouzet

Indices of fixed point classes play a central role in Nielsen fixed point theory. Jiang-Wang-Zhang proved that for selfmaps of graphs and surfaces, the index of any fixed point class has an upper bound called its characteristic. In this…

Geometric Topology · Mathematics 2020-05-26 Qiang Zhang , Xuezhi Zhao

We study fixed point sets for holomorphic automorphisms (and endomorphisms) on complex manifolds. The main object of our interest is to determine the number and configuration of fixed points that forces an automorphism (endomorphism) to be…

Complex Variables · Mathematics 2007-05-23 Buma L. Fridman , Daowei Ma , Jean-Pierre Vigue

We develop a categorical framework for studying graphs of groups and their morphisms, with emphasis on pullbacks. More precisely, building on classical work by Serre and Bass, we give an explicit construction of the so-called…

Group Theory · Mathematics 2026-04-15 Jordi Delgado , Marco Linton , Jone Lopez de Gamiz Zearra , Mallika Roy , Pascal Weil