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Related papers: The Kottman constant for $\alpha$-H\"older maps

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In this paper, we study the uniform H\"older continuity of the generalized Riemann function $R_{\alpha,\beta}$ (with $\alpha>1$ and $\beta>0$) defined by \[ R_{\alpha,\beta}(x)=\sum_{n=1}^{+\infty}\frac{\sin(\pi n^\beta x)}{n^\alpha},\quad…

Classical Analysis and ODEs · Mathematics 2014-04-02 F. Bastin , S. Nicolay , L. Simons

We prove that for harmonic quasiconformal mappings $\alpha$-H\"older continuity on the boundary implies $\alpha$-H\"older continuity of the map itself. Our result holds for the class of uniformly perfect bounded domains, in fact we can…

Complex Variables · Mathematics 2011-05-30 Miloš Arsenović , Vesna Manojlović , Matti Vuorinen

We introduce a model which allows the fine structure constant (alpha) to vary throughout space and time due to a coupling to a scalar field with a non-canonical kinetic structure. This provided a new extension of the…

General Relativity and Quantum Cosmology · Physics 2015-01-20 Alexander A. H. Graham

This paper studies the homotopy invariant $\cat(X,\xi)$ introduced in \cite{farbe2}. Given a finite cell-complex $X$, we study the function $\xi\mapsto \cat(X,\xi)$ where $\xi$ varies in the cohomology space $H^1(X;\R)$. Note that…

Algebraic Topology · Mathematics 2014-11-11 Michael Farber , Dirk Schuetz

The aim of this article is to present a concise proof for the interior H\"{o}lder continuity of two-dimensional stationary Q-valued maps. The proof employs a blow-up argument based on the monotonicity formula for the frequency function,…

Analysis of PDEs · Mathematics 2025-08-29 Chun-Chi Lin

Recently, the von Neumann-Jordan type constants C(X) has defined by Takahashi. A new skew generalized constant Cp({\lambda},\mu,X) based on C(X) constant is given in this paper. First, we will obtain some basic properties of this new…

Functional Analysis · Mathematics 2025-05-26 Yuxin Wang , Qi Liu , Yueyue Feng , Jinyu Xia , Muhammad Sarfraz

We study monotone operators in reflexive Banach spaces that are invariant with respect to a group of suitable isometric isomorphisms and we show that they always admit a maximal extension which preserves the same invariance. A similar…

Functional Analysis · Mathematics 2025-02-19 Giulia Cavagnari , Giuseppe Savaré , Giacomo Enrico Sodini

For a Banach lattice $X$, its lattice Sch\"affer constant is defined by: \begin{gather*} \lambda^+(X)=\inf\{\max\{\|x+y\|,\|x-y\|\}\,\colon\,\|x\|=\|y\|=1,x,y\geq{\bf0}\}. \end{gather*} In this paper, we investigate this constant, as well…

Functional Analysis · Mathematics 2025-05-23 Michael Alexánder Rincón Villamizar , Timur Oikhberg

The main aim of this work is to study important local Banach space constants for Boolean cube function spaces. Specifically, we focus on $\mathcal{B}_{\mathcal{S}}^N$, the finite-dimensional Banach space of all real-valued functions defined…

Functional Analysis · Mathematics 2024-05-27 Andreas Defant , Daniel Galicer , Martín Mansilla , Mieczysław Mastyło , Santiago Muro

It is known that smooth bump functions are absent in the majority of infinite-dimensional Banach spaces. This is an obstacle in the development of local analysis, in particular in the questions of extending local maps onto the whole space.…

Functional Analysis · Mathematics 2017-03-21 Genrich Belitskii , Victoria Rayskin

We consider real spaces only. Definition. An operator $T:X\to Y$ between Banach spaces $X$ and $Y$ is called a Hahn-Banach operator if for every isometric embedding of the space $X$ into a Banach space $Z$ there exists a norm-preserving…

Functional Analysis · Mathematics 2007-05-23 M. I. Ostrovskii

We present different extensions of the Banach contraction principle in the $G$-metric space setting. More precisely, we consider mappings for which the contractive condition is satisfied by a power of the mapping and for which the power…

General Topology · Mathematics 2017-04-04 Yaé Olatoundji Gaba

A strong inspiration for studying perturbation theory for fractional evolution equations comes from the fact that they have proven to be useful tools in modeling many physical processes. In this paper, we study fractional evolution…

Analysis of PDEs · Mathematics 2021-08-31 Arzu Ahmadova , Ismail T. Huseynov , Nazim I. Mahmudov

Stimulated by recent problems in the theory of iterated function systems, we provide a variant of the Banach converse theorem for multivalued maps. In particular, we show that attractors of continuous multivalued maps in a metric space are…

Dynamical Systems · Mathematics 2017-04-07 Miroslav Rypka

We study the behaviour of Whitley's thickness constant of a Banach space with respect to $\ell_p$-products and we compute it for classical $L_p$-spaces.

Functional Analysis · Mathematics 2013-07-17 Jesús M. F. Castillo , Pier Luigi Papini , Marilda A. Simoes

In this paper we study the problem of extending functions with values in a locally convex Hausdorff space $E$ over a field $\mathbb{K}$, which have weak extensions in a weighted Banach space $\mathcal{F}\nu(\Omega,\mathbb{K})$ of…

Functional Analysis · Mathematics 2023-01-03 Karsten Kruse

This paper is concerned with the characterization of $\alpha$-modulation spaces by Banach frames, i.e., stable and redundant non-orthogonal expansions, constituted of functions obtained by a suitable combination of translation, modulation…

Functional Analysis · Mathematics 2007-05-23 Massimo Fornasier

In this note we will present an extension of the Krein-Rutman theorem for an abstract nonlinear, compact, positively 1-homogeneous, monotone non-decreasing operators on a Banach space and apply the result to many nonlinear elliptic partial…

Functional Analysis · Mathematics 2007-05-23 Rajesh Mahadevan

Let $(\Omega, \mu)$, $(\Delta, \nu)$ be measure spaces. Let $(\{f_\alpha\}_{\alpha\in \Omega}, \{\tau_\alpha\}_{\alpha\in \Omega})$ and $(\{g_\beta\}_{\beta\in \Delta}, \{\omega_\beta\}_{\beta\in \Delta})$ be continuous p-Schauder frames…

Functional Analysis · Mathematics 2023-09-03 K. Mahesh Krishna

In this paper, we introduce the notions of $\alpha$-Hermitian-Einstein metric and $\alpha$-stability for $I_\pm$-holomorphic vector bundles on bi-Hermitian manifolds. Moreover, we establish a Kobayashi-Hitchin correspondence for…

Differential Geometry · Mathematics 2014-11-14 Shengda Hu , Ruxandra Moraru , Reza Seyyedali