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Haver's near-selection theorem deals with approximate selections of Hausdorff continuous CE-valued mappings defined on $\sigma$-compact metrizable $C$-spaces. In the present paper, we extend this theorem to all paracompact $C$-spaces. The…

General Topology · Mathematics 2019-12-10 Valentin Gutev

The notion of a shift-compact set in an abelian topological group $X$ plays a significant role in functional equations and inequalities, especially so since each Borel set that is not Haar-meagre, alternatively not Haar-null, is necessarily…

Classical Analysis and ODEs · Mathematics 2019-12-23 N. H. Bingham , Eliza Jablonska , Wojciech Jablonski , Adam J. Ostaszewski

An image is here defined to be a set which is either open or closed and an image transformation is structure preserving in the following sense: It corresponds to an algebra homomorphism for each singly generated algebra. The results extend…

Statistics Theory · Mathematics 2017-06-27 Gunnar Taraldsen

We study the class of compact convex subsets of a topological vector space which admits a strictly convex and lower semicontinuous function. We prove that such a compact set is embeddable in a strictly convex dual Banach space endowed with…

Functional Analysis · Mathematics 2015-10-28 L. García-Lirola , J. Orihuela , M. Raja

We first prove a version of Tietze-Urysohn's theorem for proper functions taking values in non-negative real numbers defined on $\sigma$-compact locally compact Hausdorff spaces. As its application, we prove an extension theorem of proper…

Metric Geometry · Mathematics 2022-12-27 Yoshito Ishiki

A convergence structure generalizing the order convergence structure on the set of Hausdorff continuous interval functions is defined on the set of minimal usco maps. The properties of the obtained convergence space are investigated and…

General Topology · Mathematics 2007-05-23 R Anguelov , O. F. K. Kalenda

The Runge approximation theorem for holomorphic maps (U -> C) is a fundamental result in complex analysis. The aim of this article is to prove such a result for (pseudo-)holomorphic maps from a compact Riemann surface to a compact…

Symplectic Geometry · Mathematics 2021-01-05 Antoine Gournay

In the context of complex algebraic varieties, the decomposition theorem for semi-small maps provides a decomposition of the direct image of the constant sheaf. In this work, we develop a decomposition theorem for branched coverings of…

Algebraic Topology · Mathematics 2026-03-02 Shahryar Ghaed Sharaf

We prove that a set of finite perimeter is indecomposable if and only if it is, up to a choice of suitable representative, connected in the 1-fine topology. This gives a topological characterization of indecomposability which is new even in…

Metric Geometry · Mathematics 2025-12-23 Paolo Bonicatto , Panu Lahti , Enrico Pasqualetto

We show that a fairly arbitrary Frechet space topology on the space of holomorphic functions on a domain controls the topology of uniform convergence on compact sets. In fact it turns out that the result we present can be proved more simply…

Complex Variables · Mathematics 2007-07-23 Steven G. Krantz

In analogy to the topological entropy for continuous endomorphisms of totally disconnected locally compact groups, we introduce a notion of topological entropy for continuous endomorphisms of locally linearly compact vector spaces. We study…

Group Theory · Mathematics 2021-01-22 Ilaria Castellano , Anna Giordano Bruno

Let X be a nonempty convex compact subset of some Haus-dorff locally convex topological vector space S. The well know Bauer's maximum principle stats that every convex upper semi-continuous function from X into R attains its maximum at some…

Functional Analysis · Mathematics 2018-12-19 Mohammed Bachir

We give a short proof of an improved version of the Effros Open Mapping Principle via a shift-compactness theorem (also with a short proof), involving `sequential analysis' rather than separability, deducing it from the Baire property in a…

General Topology · Mathematics 2016-06-15 A. J. Ostaszewski

This paper provides an Open Mapping Theorem for topological modules over rings that have a zero sequence consisting of units. As an application it is shown that there is a unique complete and metrisable topology on finitely generated…

Functional Analysis · Mathematics 2014-10-08 T. Henkel

We will consider various definitions of topological entropy for multivalued nonautonomous dynamical systems in compact Hausdorff spaces. Some of them can deal with arbitrary multivalued maps, i.e. when no restrictions are imposed on them.…

Dynamical Systems · Mathematics 2024-06-25 Pavel Ludvík , Jan Andres

Berge's maximum theorem gives conditions ensuring the continuity of an optimised function as a parameter changes. In this paper we state and prove the maximum theorem in terms of the theory of monoidal topology and the theory of double…

Category Theory · Mathematics 2018-07-03 Seerp Roald Koudenburg

Bidirected graphs are a generalisation of directed graphs that arises in the study of undirected graphs with perfect matchings. Menger's famous theorem - the minimum size of a set separating two vertex sets $X$ and $Y$ is the same as the…

Combinatorics · Mathematics 2023-06-29 Nathan Bowler , Ebrahim Ghorbani , Florian Gut , Raphael W. Jacobs , Florian Reich

A map $f:X\to Y$ between topological spaces is defined to be {\em scatteredly continuous} if for each subspace $A\subset X$ the restriction $f|A$ has a point of continuity. We show that for a function $f:X\to Y$ from a perfectly paracompact…

Geometric Topology · Mathematics 2011-10-11 T. Banakh , B. Bokalo

The Serre-Swan theorem provides the link between projective modules of finite rank and vector bundles over compact manifolds, and plays a prominent role in non-commutative geometry. Its extension to non-compact manifolds is discussed.

Mathematical Physics · Physics 2007-05-23 G. Sardanashvily

Working over infinite dimensional separable Hilbert spaces, residual results have been achieved for the space of contractive $C_{0}$-semigroups under the topology of uniform weak operator convergence on compact subsets of $\mathbb{R}_{+}$.…

Functional Analysis · Mathematics 2023-02-02 Raj Dahya