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Related papers: Urysohn Lemmas in Topological Vector Spaces

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We investigate the open Closing Lemma problem for vector fields on the 2-dimensional torus. Under the assumption of bounded type rotation number, the $C^r$ Closing Lemma is verified for smooth vector fields that are area-preserving at all…

Dynamical Systems · Mathematics 2010-01-29 Simon Lloyd

We give characterizations of unital uniform topological algebras and saturated locally multiplicatively convex algebras by means of multiplicative linear functionals. Some automatic continuity theorems in advertibly complete uniform…

Functional Analysis · Mathematics 2014-01-03 M. El Azhari

The concept of quasi-partial b-metric-like spaces is being introduced and studied with the help of topology. Examples are also discussed to support the results. Some fixed point theorems are proved in the setting of quasi-partial…

General Topology · Mathematics 2018-12-04 Anuradha Gupta , Manu Rohilla

We present a translation of Urysohn's description of normal spaces (as those where disjoint closed subsets are separated by a continuous function) into the language of lifting properties in $\mathbf{Top}$, correcting a frequently-cited…

General Topology · Mathematics 2026-02-13 Robert Maxton

We prove some extension theorems involving uniformly continuous maps of the universal Urysohn space. We also prove reconstruction theorems for certain groups of autohomeomorphisms of this space and of its open subsets.

Metric Geometry · Mathematics 2012-10-23 Wieslaw Kubiś , Matatyahu Rubin

A subclass of complex-valued close-to-convex harmonic functions that are univalent and sense-preserving in the open unit disc is investigated. The coefficient estimates, growth results, area theorem, boundary behavior, convolution and…

Complex Variables · Mathematics 2012-07-17 Sumit Nagpal , V. Ravichandran

Realization by linear vector fields is constructed for any Lie algebra which admits a biorthogonal system and for its any suitable representation. The embedding into Lie algebras of linear vector fields is analogous to the classical…

Functional Analysis · Mathematics 2019-09-04 Wolfgang Bock , Vyacheslav Futorny , Mikhail Neklyudov

We characterize the valuations on the space of quasi-concave functions defined on the $N$-dimensional Euclidean space, that are rigid motion invariant and continuous with respect to a suitable topology. Among them we also provide a specific…

Metric Geometry · Mathematics 2015-12-02 Andrea Colesanti , Nico Lombardi

A new and extensive formalism is developed for monads and galaxies in non-standard enlargements. It is shown that monads and galaxies can be manipulated using order-preserving and order-reversing set-to-set maps, and that set properties…

Logic · Mathematics 2024-06-12 Niels Charlier , Hans Vernaeve

We introduce and study the notion of orthosymmetric spaces over an Archimedean vector lattice as a generalization of finite-dimentional Euclidean inner spaces. A special attention has been paid to linear operators on these spaces.

Functional Analysis · Mathematics 2019-10-29 Mohamed Amine Ben Amor , Karim Boulabiar , Jamel Jaber

We formulate a multi-valued version of the Tietze-Urysohn extension theorem. Precisely, we prove that any upper semicontinuous multi-valued map with nonempty closed convex values defined on a closed subset (resp. closed perfectly normal…

General Topology · Mathematics 2008-10-20 Youcef Askoura

We prove various results on the size and structure of subsets of vector spaces over finite fields which, in some sense, have too many mutually orthogonal pairs of vectors. In particular, we obtain sharp finite field variants of a theorem of…

Combinatorics · Mathematics 2022-05-05 Ali Mohammadi , Giorgis Petridis

We obtain new general results on the structure of the space of translation invariant continuous valuations on convex sets (a version of the hard Lefschetz theorem). Using these and our previous results we obtain explicit characterization of…

Metric Geometry · Mathematics 2007-05-23 Semyon Alesker

We consider the space of functions almost in $L_p$ and endow it with the topology of asymptotic $L_p$-convergence. This yields a completely metrizable topological vector space which, on finite measure spaces, coincides with the space of…

Functional Analysis · Mathematics 2025-12-01 Nuno J. Alves

We prove a uniformly continuous linear extension principle in topological vector spaces from which we derive a very short and canonical construction of the Lebesgue integral of Banach space valued maps on a finite measure space. The Vitali…

Functional Analysis · Mathematics 2013-05-08 Ben Berckmoes

To investigate the topological structure of Morse functions on the projective plane we use the Reeb graphs. We describe it properties and prove that it is a complete topological invariant of simple Morse function on $\mathbb{R} P^2$. We…

Geometric Topology · Mathematics 2023-03-08 Svitlana Bilun , Alexandr Prishlyak , Serhii Stas , Alina Vlasenko

We study the continuous solutions of several classical functional equations by using the properties of the spaces of continuous functions which are invariant under some elementary linear trans-formations. Concretely, we use that the sets of…

Classical Analysis and ODEs · Mathematics 2013-10-30 J. M. Almira , Kh. F. Abu-Helaiel

In this paper, we give new constructions of Urysohn universal ultrametric spaces. We first characterize a Urysohn universal ultrametric subspace of the space of all continuous functions whose images contain the zero, from a zero-dimensional…

Metric Geometry · Mathematics 2023-02-17 Yoshito Ishiki

In this paper, we introduce the concepts of weaknorm, quasi-weaknorm on real vector spaces. By these concepts, we introduce the concept of quasi-locally convex topological vector spaces, which include locally convex topological vector…

Functional Analysis · Mathematics 2020-01-01 Jinlu Li

Let E be a locally solid vector lattice. In this paper, we consider two particular vector subspaces of the space of all order bounded operators on E. With the aid of two appropriate topologies, we show that under some conditions, they…

Functional Analysis · Mathematics 2016-11-07 Omid Zabeti