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Under a general categorical procedure for the extension of dual equivalences as presented in this paper's predecessor, a new algebraically defined category is established that is dually equivalent to the category $\bf LKHaus$ of locally…

Category Theory · Mathematics 2021-09-16 G. Dimov , E. Ivanova-Dimova , W. Tholen

We introduce notions of compactness and weak compactness for multilinear maps from a product of normed spaces to a normed space, and prove some general results about these notions. We then consider linear maps $T:A\to B$ between Banach…

Functional Analysis · Mathematics 2009-01-23 M. J Heath

Let $\kappa$ be an infinite cardinal. A topological space $X$ is $\kappa$-bounded if the closure of any subset of cardinality $\le\kappa$ in $X$ is compact. We discuss the problem of embeddability of topological spaces into Hausdorff…

General Topology · Mathematics 2021-11-02 T. Banakh , S. Bardyla , A. Ravsky

The following selection theorem is established:\\ Let $X$ be a compactum possessing a binary normal subbase $\mathcal S$ for its closed subsets. Then every set-valued $\mathcal S$-continuous map $\Phi\colon Z\to X$ with closed $\mathcal…

General Topology · Mathematics 2013-11-05 Vesko Valov

We investigate closed subsets (subsemigroups, resp.) of compact-like topological spaces (semigroups, resp.). We prove that each Hausdorff topological space can be embedded as a closed subspace into an H-closed topological space. However,…

General Topology · Mathematics 2019-08-09 Serhii Bardyla , Alex Ravsky

In this paper we classify, under certain restrictions, all homogeneous conformal subalgebras $\goth L$ of a lattice vertex superalgebra $V_\Lambda$ corresponding to an integer lattice $\Lambda$. We require that $\goth L$ is graded by an…

Quantum Algebra · Mathematics 2007-05-23 Michael Roitman

We prove that if ZF is consistent then ZFC+GCH is consistent with the following statement: There is for every k<omega a model of cardinality aleph_1 which is L_{infty,omega_1}-equivalent to exactly k non-isomorphic models of cardinality…

Logic · Mathematics 2007-05-23 Saharon Shelah , Pauli Vaisanen

We use the structure lattice, introduced in Part I, to undertake a systematic study of the class $\mathscr S$ consisting of compactly generated, topologically simple, totally disconnected locally compact groups that are non-discrete. Given…

Group Theory · Mathematics 2017-07-07 Pierre-Emmanuel Caprace , Colin D. Reid , George A. Willis

A Hausdorff topological group is called minimal if it does not admit a strictly coarser Hausdorff group topology. This paper mostly deals with the topological group $H_+(X)$ of order-preserving homeomorphisms of a compact linearly ordered…

General Topology · Mathematics 2015-06-19 Michael Megrelishvili , Luie Polev

We show in detail that every compact countable subset of a metric space is homeomorphic to a countable ordinal number, which extends a result given by Mazurkiewicz and Sierpinski for finite-dimensional Euclidean spaces. In order to achieve…

General Topology · Mathematics 2019-11-12 Borys Álvarez-Samaniego , Andrés Merino

It is a classic result in modal logic that the category of modal algebras is dually equivalent to the category of descriptive frames. The latter are Kripke frames equipped with a Stone topology such that the binary relation is continuous.…

General Topology · Mathematics 2020-08-14 Guram Bezhanishvili , Luca Carai , Patrick Morandi

There exists a holomorphic quadratic differential defined on any $H-$ surface immersed in the homogeneous space $\mathbb{E}(\kappa,\tau)$ given by U. Abresch and H. Rosenberg, called the Abresch-Rosenberg differential. However, there were…

Differential Geometry · Mathematics 2016-06-22 José M. Espinar , Haimer A. Trejos

An equilevel algebra is a subalgebra of the space of smooth functions $f: M \to {\mathbb R}$ distinguished in this space by finitely many linear conditions of the type $f(x_i) = f(\tilde x_i)$, $x_i \neq \tilde x_i \in M$, or approximated…

Algebraic Geometry · Mathematics 2025-06-03 V. A. Vassiliev

The classical theorems of Banach and Stone, Gelfand and Kolmogorov, and Kaplansky show that a compact Hausdorff space $X$ is uniquely determined by the linear isometric structure, the algebraic structure, and the lattice structure,…

Functional Analysis · Mathematics 2013-10-29 Denny H. Leung , Lei Li

We characterize when an Orlicz space $L^A$ is almost compactly (uniformly absolutely continuously) embedded into a Lorentz space $L^{p,q}$ in terms of a balance condition involving parameters $p,q\in[1,\infty]$, and a Young function $A$. In…

Functional Analysis · Mathematics 2024-10-04 Vít Musil , Luboš Pick , Jakub Takáč

Let $n>1$ be an integer. We prove that holomorphic maps from Stein manifolds $X$ of dimension $<n$ to the complement $\mathbb{C}^n\setminus L$ of a compact convex set $L\subset\mathbb{C}^n$ satisfy the basic Oka property with approximation…

Complex Variables · Mathematics 2017-03-30 Franc Forstneric , Tyson Ritter

Let $X$ be a locally compact topological space, $(Y,d)$ be a boundedly compact metric space and $LB(X,Y)$ be the space of all locally bounded functions from $X$ to $Y$. We characterize compact sets in $LB(X,Y)$ equipped with the topology of…

General Topology · Mathematics 2018-03-29 Ľubica Holá , Dušan Holý

For a topological space $X$, let $X_\delta$ be the space $X$ with $G_\delta$-topology of $X$. For an uncountable cardinal $\kappa$, we prove that the following are equivalent: (1) $\kappa$ is $\omega_1$-strongly compact. (2) For every…

Logic · Mathematics 2018-07-23 Toshimichi Usuba

Given a non compact semisimple Lie group $G$ we describe all homogeneous spaces $G/L$ carrying an invariant almost K\"ahler structure $(\omega,J)$. When $L$ is abelian and $G$ is of classical type, we classify all such spaces which are…

Differential Geometry · Mathematics 2018-12-07 Dmitri V. Alekseevsky , Fabio Podestà

Answering questions of A. Avil\'es, F. Cabello S\'anchez, J. Castillo, M. Gonz\'alez and Y. Moreno we show that the following statements are independent of the usual axioms ZFC with arbitrarily large continuum: for every (some)…

Functional Analysis · Mathematics 2025-12-10 Piotr Koszmider , Małgorzata Rojek