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In this paper, we study some properties of $*-$open and $*-$closed subsets of a space. The collection of all $*-$open subsets of a space $X$ form a topology on $X$ which is denoted by $^{*}O(X)$. We investigate the relations between…

General Topology · Mathematics 2023-06-13 Aliakbar Alijani

Well-graded families, extremal systems and maximum systems (the last two in the sense of VC-theory and Sauer-Shelah lemma on VC-dimension) are three important classes of set systems. This paper aims to study the notion of duality in the…

Combinatorics · Mathematics 2022-12-19 Alireza Mofidi

Let $X$ be a Hausdorff topological vector space, $X^*$ its topological dual and $Z$ a subset of $X^*$. In this paper, we establish some results concerning the $\sigma(X,Z)$-approximate fixed point property for bounded, closed convex subsets…

Functional Analysis · Mathematics 2012-07-19 Cleon S. Barroso , Ondřej F. K. Kalenda , Pei-Kee Lin

This expository article is devoted to the notion of quasianalytic classes and the Borel mapping. Although quasianalytic classes are well known in analysis since several decades. We are interested in certain properties of Denjoy-Carleman's…

Classical Analysis and ODEs · Mathematics 2025-01-06 Abdelhafed Elkhadiri

We develop a dynamical version of some of the theory surrounding the Toms-Winter conjecture for simple separable nuclear C*-algebras and study its connections to the C*-algebra side via the crossed product. We introduce an analogue of…

Dynamical Systems · Mathematics 2020-06-05 David Kerr

Ramsey theory looks for regularities in large objects. Model theory studies algebraic structures as models of theories. The structural Ramsey theory combines these two fields and is concerned with Ramsey-type questions about certain…

Combinatorics · Mathematics 2018-05-22 Matěj Konečný

A theorem is established where the computation of the discrete Conley index for zero dimensional basic sets is given with respect to the dynamical information contained in the associated structure matrices. A classification of the reduced…

Dynamical Systems · Mathematics 2015-04-16 Ketty A. de Rezende , Mariana G. Villapouca

We discuss in detail the dynamics of maps $z\mapsto ae^z+be^{-z}$ for which both critical orbits are strictly preperiodic. The points which converge to $\infty$ under iteration contain a set $R$ consisting of uncountably many curves called…

Dynamical Systems · Mathematics 2007-08-21 Dierk Schleicher

We investigate the large scale geometry of certain metric spaces through the lens of dynamics. Our approach establishes a close connection between large scale dynamical phenomena and operator algebras by characterizing various large scale…

Operator Algebras · Mathematics 2026-04-30 Bruno de Mendonça Braga , Alcides Buss , Ruy Exel

We study minimal sets on continua $X$ with a dense free interval $J$ and a locally connected remainder. This class of continua includes important spaces such as the topologist's sine curve or the Warsaw circle. In the case when minimal sets…

Dynamical Systems · Mathematics 2022-03-04 Michaela Mihoková

According to Cantor, a set is a collection into a whole of defined and separate (we shall say distinct) objects. So, a natural question is ``How to treat as `sets' collections of indistinguishable objects?". This is the aim of quasi-set…

Logic · Mathematics 2007-05-23 Aurelio Sartorelli , Decio Krause , Adonai S. Sant'Anna

We establish the dual equivalence of the category of (potentially nonunital) operator systems and the category of pointed compact nc (noncommutative) convex sets, extending a result of Davidson and the first author. We then apply this dual…

Operator Algebras · Mathematics 2021-03-24 Matthew Kennedy , Se-Jin Kim , Nicholas Manor

Real algebraic geometry is the study of semi-algebraic sets, subsets of $\R^k$ defined by Boolean combinations of polynomial equalities and inequalities. The focus of this thesis is to study quantitative results in real algebraic geometry,…

Algebraic Geometry · Mathematics 2013-08-01 Salvador Barone

A general notion of a quasi-finite algebra is introduced as an algebra graded by the set of all integers equipped with topologies on the homogeneous subspaces satisfying certain properties. An analogue of the regular bimodule is introduced…

Quantum Algebra · Mathematics 2007-05-23 Atsushi Matsuo , Kiyokazu Nagatomo , Akihiro Tsuchiya

The aim of this paper is to introduce the notion of cornets, which form a particular subclass of ordered semigroups also equipped with a multiplication by natural numbers. The most important standard examples for cornets are the families of…

Group Theory · Mathematics 2020-08-05 Gábor M. Molnár , Zsolt Páles

In this paper, we deal with the classification complexity of continuous (Devaney) chaotic systems in dimensions $0,1$ and $\infty$ using the framework of invariant descriptive set theory. We identify the complexity in dimensions $0$ and…

Dynamical Systems · Mathematics 2026-04-22 Benjamin Vejnar

An important theorem of geometric measure theory (first proved by Besicovitch and Davies for Euclidean space) says that every analytic set of non-zero $s$-dimensional Hausdorff measure $\mathcal H^s$ contains a closed subset of non-zero…

Logic · Mathematics 2014-08-12 Bjørn Kjos-Hanssen , Jan Reimann

We introduce the dynamic comparison property for minimal dynamical systems which has applications to the study of crossed product C*-algebras. We demonstrate that this property holds for a large class of systems which includes all examples…

Dynamical Systems · Mathematics 2013-07-01 Julian Buck

Soft set theory provides a direct framework for parameterized decision modeling by assigning to each attribute (parameter) a subset of a given universe, thereby representing uncertainty in a structured way [1, 2]. Over the past decades, the…

Artificial Intelligence · Computer Science 2026-03-17 Takaaki Fujita , Florentin Smarandache

In this article, we introduce and investigate the concept of partial quasi-metric type space as a generalization of both partial quasi-metric and quasi-metric type spaces. We show that many important constructions studied in K\"unzi's…

General Topology · Mathematics 2019-03-18 Yaé Ulrich Gaba