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Related papers: Functional approach to the normality of mappings

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Urysohn's Lemma is a crucial property of normal spaces that deals with separation of closed sets by continuous functions. It is also a fundamental ingredient in proving the Tietze Extension Theorem, another property of normal spaces that…

General Topology · Mathematics 2021-05-21 Florica C. Cîrstea

Beardon and Minda gave a characterization of normal families of holomorphic and meromorphic functions in terms of a locally uniform Lipschitz condition. Here, we generalize this viewpoint to families of mappings in higher dimensions that…

Complex Variables · Mathematics 2022-01-25 Alastair N. Fletcher , Daniel A. Nicks

The present paper is devoted to the study of classes of mappings with non--bounded characteristics of quasiconformality. It is proved that the normal families of mappings distorting the families of mappings in ${\Bbb R}^n$ by special way,…

Complex Variables · Mathematics 2013-09-04 Evgeny Sevost'yanov

The main purpose of this paper is to explore normality in terms of distances between points and sets. We prove some important consequences on realvalued contractions, i.e. functions not enlarging the distance, showing that as in the…

General Topology · Mathematics 2018-06-19 E. Colebunders , M. Sioen , W. Van Den Haute

We give several unequivalent notions of convergency of meromorphic functions and more generally meromorphic mappings (strong, weak, $\Gamma $-convergency and some others). Relations between them are investigated. A version of Rouche theorem…

Complex Variables · Mathematics 2016-09-07 Sergei Ivashkovich

In this paper, we show that some fundamental results for smooth mappings (e.g., the Brouwer degree formula, the implicit function and inverse function theorems, the mean value theorem, Sard's theorem, Hadamard's global invertibility…

Functional Analysis · Mathematics 2021-05-26 Xuan Duc Ha Truong , Tien Son Pham

The authors lay the foundations for the study of normal families of holomorphic functions and mappings on an infinite-dimensional normed linear space. Characterizations of normal families, in terms of value distribution, spherical…

Complex Variables · Mathematics 2007-05-23 Kang-Tae Kim , Steven Krantz

The main purpose of this paper is to study the concept of normal function in the context of harmonic mappings from the unit disk $\mathbb{D}$ to the complex plane. In particular, we obtain necessary conditions for that a function $f$ to be…

Complex Variables · Mathematics 2018-04-10 Hugo Arbeláez , Rodrigo Hernández , Willy Sierra

We establish arithmetical properties and provide essential bounds for bi-sequences of approximation coefficients associated with the natural extension of maps, leading to continued fraction-like expansions. These maps are realized as the…

Number Theory · Mathematics 2012-11-22 Avraham Bourla

Using the notion of modulus of continuity at a point of a mapping between metric spaces, we introduce the notion of extensively bounded mappings generalizing that of Lipschitz mappings. We also introduce a metric on it which becomes a norm…

Functional Analysis · Mathematics 2025-01-06 Anil Kumar Karn , Arindam Mandal

In this paper, we study the concepts of normal functions and $\varphi$-normal functions in the framework of planar harmonic mappings. We establish the harmonic mapping counterpart of the well-known Zalcman-Pang lemma and as a consequence,…

Complex Variables · Mathematics 2025-06-24 Nikhil Bharti , Nguyen Van Thin

We introduce the notion of (hybrid) large scale normal space and prove coarse geometric analogues of Urysohn's Lemma and the Tietze Extension Theorem for these spaces, where continuous maps are replaced by (continuous and) slowly…

Metric Geometry · Mathematics 2018-10-23 Jerzy Dydak , Thomas Weighill

In this paper, we consider certain topological properties along with certain types of mappings on these spaces defined by the notion of ideal convergence. In order to do that, we primarily follow in the footsteps of the earlier studies of…

General Topology · Mathematics 2023-01-03 Pratulananda Das , Upasana Samanta , Shou Lin

Using the recent theory of Krein--von Neumann extensions for positive functionals we present several simple criteria to decide whether a given positive functional on the full operator algebra is normal. We also characterize those…

Functional Analysis · Mathematics 2017-10-19 Zoltán Sebestyén , Zsigmond Tarcsay , Tamás Titkos

The aim of the current paper is to introduce a new class of contractive mappings, which are contracting (a feature of) triangles. We prove that maps contracting triangles are continuous and give the fixed point result for such mappings. We…

General Topology · Mathematics 2024-03-29 Ovidiu Popescu , Cristina Maria Pacurar

We show how our recent results on compositions of d.c. functions (and mappings) imply positive results on extensions of d.c. functions (and mappings). Examples answering two natural relevant questions are presented. Two further theorems,…

Functional Analysis · Mathematics 2008-10-09 Libor Vesely , Ludek Zajicek

The main result of this paper is a proof of the continuity of a family of integral functionals defined on the space of functions of bounded variation with respect to a topology under which smooth functions are dense. These functionals occur…

Analysis of PDEs · Mathematics 2014-11-24 Filip Rindler , Giles Shaw

We study the regularity results of holomorphic correspondences. As an application, we combine it with certain recently developed methods to obtain the extension theorem for proper holomorphic mappings between domains with real analytic…

Complex Variables · Mathematics 2016-09-06 Xiaojun Huang

As an application of Brouwer's fixed-point theorem we prove that a continuously differentiable convex function with gradient of constant norm is an affine mapping. It is a first-order characterization of affine mappings among continuously…

Classical Analysis and ODEs · Mathematics 2025-11-10 Csaba Vincze

In the present paper, we introduced the extended bicomplex plane $\bar{\mathbb{T}}$, its geometric model: the bicomplex Riemann sphere, and the bicomplex chordal metric that enables us to talk about the convergence of the sequences of…

Complex Variables · Mathematics 2011-05-24 K. S. Charak , D. Rochon , N. Sharma
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