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We propose halfspace depth concepts for scatter, concentration and shape matrices. For scatter matrices, our concept is similar to those from Chen, Gao and Ren (2017) and Zhang (2002). Rather than focusing, as in these earlier works, on…

Statistics Theory · Mathematics 2017-10-27 Davy Paindaveine , Germain Van Bever

We explore the interplay between different definitions of distortion for mappings $f\colon X\to \mathbb{R}^2$, where $X$ is any metric surface, meaning that $X$ is homeomorphic to a domain in $\mathbb{R}^2$ and has locally finite…

Metric Geometry · Mathematics 2024-05-14 Damaris Meier , Kai Rajala

In this paper we define fuzzy sequential topology on a non empty set X which is a collection of fuzzy sequential sets satisfying certain conditions given in its definition and many pleasant properties of a countable number of fuzzy…

General Topology · Mathematics 2012-09-27 M. Singha , N. Tamang , S. De Sarkar

Instead of formulating the states of a Quantum Field Theory (QFT) as density matrices over a single large Hilbert space, it has been proposed by Kijowski [Kijowski, 1977] to construct them as consistent families of partial density matrices,…

High Energy Physics - Theory · Physics 2016-04-20 Suzanne Lanéry

This paper is concerned with the characterizations of quasi self-adjoint extensions of a class of formally non-self-adjoint discrete Hamiltonian systems. Some properties of the solutions and the characterization of the minimal linear…

Spectral Theory · Mathematics 2025-12-11 Guojing Ren , Guixin Xu

We prove that: 1. If a Hausdorff M-space is a continuous closed image of a submetrizable space, then it is metrizable. 2. A dense-in-itself open-closed image of a submetrizable space is submetrizable if and only if it is functionally…

General Topology · Mathematics 2023-12-07 Vlad Smolin

We investigate two constructive approaches to defining quasi-compact and quasi-separated schemes (qcqs-schemes), namely qcqs-schemes as locally ringed lattices and as functors from rings to sets. We work in Homotopy Type Theory and…

Algebraic Geometry · Mathematics 2024-07-25 Max Zeuner

In this paper, we study a special class of quasi-homomorphisms, i.e. quasi-retractions from a group to its subgroups. We first give some algebraic and geometric properties of quasi-retracts and then propose a theory of quasi-split short…

Group Theory · Mathematics 2025-08-21 Renxing Wan

The definition of quasi-local mass for a bounded space-like region in space-time is essential in several major unsettled problems in general relativity. The quasi-local mass is expected to be a type of flux integral on the boundary…

Differential Geometry · Mathematics 2009-11-13 Mu-Tao Wang , Shing-Tung Yau

We define a distance analogous to the Gromov-Hausdorff distance that enables the comparison of arbitrary quasi-isometric spaces. We also investigate properties preserved under limits with respect to this distance, as well as properties of…

Metric Geometry · Mathematics 2026-05-28 Alexei Naianzin

We explore the structure of the space of quasisymmetric configurations identifying them by their magnetic axes, described as 3D closed curves. We demonstrate that this topological perspective divides the space of all configurations into…

Plasma Physics · Physics 2022-09-14 Eduardo Rodriguez , Wrick Sengupta , Amitava Bhattacharjee

In this paper we study flag codes on $\mathbb{F}_q^n$, being $\mathbb{F}_q$ the finite field with $q$ elements. Special attention is given to the connection between the parameters and properties of a flag code and the ones of a family of…

Information Theory · Computer Science 2020-12-21 Clementa Alonso-González , Miguel Ángel Navarro-Pérez

In this paper, we use the concept of proximal quasi-normal structure (P. Q-N. S) to study the existence of best proximity points for cyclic mappings, cyclic contractions, relatively Kannan nonexpansive mappings, as well as for orbitally…

Functional Analysis · Mathematics 2019-07-26 Farhad Fouladi , Ali Abkar

On a complete, connected, locally compact, non-compact geodesic space $(X,d)$, we assign each compact set a distance-like function. With the help of these functions, we obtain a pseudo-metric on the space of (non-empty) compact subsets of…

Dynamical Systems · Mathematics 2022-02-01 Xiaojun Cui , Liang Jin , Xifeng Su

We address various notions of shadowing and expansivity for continuous maps restricted to a proper subset of their domain. We prove new equivalences of shadowing and expansive properties, we demonstrate under what conditions certain…

Dynamical Systems · Mathematics 2015-05-20 Andrew Barwell , Chris Good , Piotr Oprocha

In this paper we examine two basic topological properties of partial metric spaces, namely compactness and completeness. Our main result claims that in these spaces compactness is equivalent to sequential compactness. We also show that…

General Topology · Mathematics 2022-02-01 Dariusz Bugajewski , Piotr Maćkowiak , Ruidong Wang

Representations of domains mean in a general way representing a domain as a suitable family endowed with set-inclusion order of some mathematical structures. In this paper, representations of domains via CF-approximation spaces are…

Rings and Algebras · Mathematics 2023-06-22 Guojun Wu , Luoshan Xu

The notion of a rigid quasilocal frame (RQF) provides a geometrically natural way to define a system in general relativity, and a new way to analyze the problem of motion. An RQF is defined as a two-parameter family of timelike worldlines…

General Relativity and Quantum Cosmology · Physics 2013-07-09 Richard J. Epp , Robert B. Mann , Paul L. McGrath

We give necessary and sufficient conditions for a real-valued quasiconvex function f on a Baire topological vector space X (in particular, Banach or Frechet space) to be continuous at the points of a residual subset of X. These conditions…

Optimization and Control · Mathematics 2015-01-20 Patrick J. Rabier

In this paper we explore some basic properties of quasi-Banach function spaces which are important in applications. Namely, we show that they posses a generalised version of Riesz--Fischer property, that embeddings between them are always…

Functional Analysis · Mathematics 2024-12-04 Aleš Nekvinda , Dalimil Peša