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We provide a complete classification of the possible cofinal structures of the families of precompact (totally bounded) sets in general metric spaces, and compact sets in general complete metric spaces. Using this classification, we…

General Topology · Mathematics 2017-01-04 Aviv Eshed , M. Vincenta Ferrer , Salvador Hernández , Piotr Szewczak , Boaz Tsaban

The fundamental bigroupoid of a topological space is one way of capturing its homotopy 2-type. When the space is semilocally 2-connected, one can lift the construction to a bigroupoid internal to the category of topological spaces, as Brown…

Algebraic Topology · Mathematics 2018-02-02 David Michael Roberts

In many applications it is important to establish if a given topological preordered space has a topology and a preorder which can be recovered from the set of continuous isotone functions. Under antisymmetry this property, also known as…

General Topology · Mathematics 2013-06-21 E. Minguzzi

This work introduces nodal auxiliary space preconditioners for discretizations of mixed-dimensional partial differential equations. We first consider the continuous setting and generalize the regular decomposition to this setting. With the…

Numerical Analysis · Mathematics 2019-10-15 Ana Budisa , Wietse Boon , Xiaozhe Hu

We define the concept of a bi-operad. We develop the homotopy theory of "Bital-Sets" and of infinite-bi-operads. We develop a geometry of generalized schemes based on the spectra of distributive monochromatic bi-operads.

Algebraic Topology · Mathematics 2022-04-08 Shai Haran

Birkhoff's 1937 dual representation of finite distributive lattices via finite posets was in 1970 extended to a dual representation of arbitrary distributive lattices via compact totally order-disconnected topological spaces by Priestley.…

Rings and Algebras · Mathematics 2026-04-07 Andrew Craig , Miroslav Haviar , José São João

Here we have studied on the ideas of $g_{\mu_i}$ and $\lambda_{\mu_i}$-closed sets with respect to ${\mu_j}(i,j=1,2,i\not=j)$ and pairwise $ \lambda $-closed sets in a generalized bitopological space $ (X,\mu_1, \mu_2) $. We have also…

General Topology · Mathematics 2018-10-15 Amar Kumar Banerjee , Jagannath Pal

The study of infra-topological spaces focuses on characterizations of $e^\star$-open sets and nearby open sets in infra-topological spaces. The $e^\star$-open sets, a variation of open sets, are explored for their unique properties and…

General Topology · Mathematics 2024-03-05 G. Saravanakumar , D. Jaya Priya

The aim of this work is to introduce and study some new types of generalizations of pairwise paralindeloff spaces, pairwise nearly paralindeloff and almost paralindeloff spaces. Some of their characterizations, properties and subsets are…

General Topology · Mathematics 2015-01-05 Hend Bouseliana , Adem Kilicman

The problem of bi-equivariant extension of continuous maps of binary $G$-spaces is considered. The concept of a structural map of distributive binary $G$-spaces is introduced, and a theorem on the bi-equivariant extension of structural maps…

General Topology · Mathematics 2025-09-11 Pavel S. Gevorgyan

The origins of the notion of matchings in groups spawn from a linear algebra problem proposed by E. K. Wakeford [24] which was tackled in 1996 [10]. In this paper, we first discuss unmatchable subsets in abelian groups. Then we formulate…

Combinatorics · Mathematics 2022-03-09 Mohsen Aliabadi , Jack Kinseth , Christopher Kunz , Haris Serdarevic , Cole Wills

We establish that every second countable completely regularly preordered space (E,T,\leq) is quasi-pseudo-metrizable, in the sense that there is a quasi-pseudo-metric p on E for which the pseudo-metric p\veep^-1 induces T and the graph of…

General Topology · Mathematics 2012-11-21 E. Minguzzi

We introduce and study the notion of overcomplete set in a Banach space, that subsumes and extends the classical concept of overcomplete sequence in a (separable) Banach space. We give existence and non-existence results of overcomplete…

Functional Analysis · Mathematics 2021-01-13 Tommaso Russo , Jacopo Somaglia

We extend the C*-algebra semicontinuity theory of Akemann, Brown and Pedersen to (pre)ordered Banach spaces.

Functional Analysis · Mathematics 2016-04-13 Tristan Bice

In this paper we give various characterizations of quasiopen sets and quasicontinuous functions on metric spaces. For complete metric spaces equipped with a doubling measure supporting a p-Poincar\'e inequality we show that quasiopen and…

Functional Analysis · Mathematics 2017-02-13 Anders Björn , Jana Björn , Jan Malý

We show that the product of any number of sequentially pseudocompact topological spaces is still sequentially pseudocompact. The definition of sequential pseudocompactness can be given in (at least) two ways: we show their equivalence. Some…

General Topology · Mathematics 2016-04-19 Paolo Lipparini

We study conditions under which a space that has a good property and a courser topology with another good property admits a continuous bijection onto a space with both properties.

General Topology · Mathematics 2025-10-21 Alexander Arhangel'skii , Raushan Buzyakova

In this paper we adhere to the definition of infra-topological space as it was introduced by Al-Odhari. Namely, we speak about families of subsets which contain empty set and the whole universe X, being at the same time closed under finite…

Logic · Mathematics 2021-01-07 Tomasz Witczak

Over the past years a theory of conjugate duality for set-valued functions that map into the set of upper closed subsets of a preordered topological vector space was developed. For scalar duality theory, continuity of convex functions plays…

Optimization and Control · Mathematics 2014-03-13 Frank Heyde , Carola Schrage

Rough set theory is a new mathematical approach to imperfect knowledge. The notion of rough sets is generalized by using an arbitrary binary relation on attribute values in information systems, instead of the trivial equality relation. The…

General Mathematics · Mathematics 2015-02-24 M. Abo-Elhamayel