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Related papers: Enveloping balls of Szlenk derivations

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In this paper we prove two Bloch type theorems for quaternionic slice regular functions. We first discuss the injective and covering properties of some classes of slice regular functions from slice regular Bloch spaces and slice regular…

Complex Variables · Mathematics 2016-01-12 Zhenghua Xu , Xieping Wang

In this paper, we obtain two-sided bounds for the volumes of the Aloff-Wallach spaces $W(p,q),$ compute maximal and minimal sectional curvature for the spaces $W(n,n+1),$ and use this information to estimate the injectivity radii: We derive…

Differential Geometry · Mathematics 2007-05-23 Mikhail Alyurov

Suppose $\mathcal{Z}$ is the space of all tuples of operators on a finite-dimensional Banach space endowed with the joint numerical radius norm. We obtain the structure of the extreme points of the dual unit ball of $\mathcal{Z}.$ Using…

Functional Analysis · Mathematics 2025-07-08 Arpita Mal

We prove some rather precise renorming theorems for Banach spaces with Szlenk index $\omega_0$. We use these theorems to show the invariance of certain quantitative Szlenk-type indices under uniform homeomorphisms.

Functional Analysis · Mathematics 2007-05-23 G. Godefroy , N. J. Kalton , G. Lancien

We prove that, given any covering of any separable infinite-dimensional uniformly rotund and uniformly smooth Banach space $X$ by closed balls each of positive radius, some point exists in $X$ which belongs to infinitely many balls.

Functional Analysis · Mathematics 2012-12-13 Vladimir P. Fonf , Michael Levin , Clemente Zanco

We give upper bounds for the density of unit ball packings relative to their outer parallel domains and discuss their connection to contact numbers. Also, packings of soft balls are introduced and upper bounds are given for the fraction of…

Metric Geometry · Mathematics 2015-11-24 Karoly Bezdek , Zsolt Langi

We observe that the $k$-dimensional width of an $n$-ball in a space form is given by the area of an equatorial $k$-ball. We also investigate related lower bounds for the area of a free boundary minimal submanifold in a space form ball.

Differential Geometry · Mathematics 2022-08-01 Jonathan J. Zhu

Inspired by R. Whitley's thickness index the last named author recently introduced the Daugavet index of thickness of Banach spaces. We continue the investigation of the behavior of this index and also consider two new versions of the…

Functional Analysis · Mathematics 2020-05-18 Rainis Haller , Johann Langemets , Vegard Lima , Rihhard Nadel , Abraham Rueda Zoca

We obtain upper bounds for the norm of the Schwarzian derivative of convex holomorphic mappings defined on the polydisk and the unit ball in $\mathbb{C}^n$. For coordinate-wise convex mappings on the polydisk, we derive a sharp estimate…

Complex Variables · Mathematics 2026-04-15 Rodrigo Hernández

Given any Banach space $X$ and any weak*-compact subset $K$ of $X^*$, we compute the Szlenk index of the weak*-closed, convex hull of $K$ as a function of the Szlenk index of $K$. Also as an application, we compute the Szlenk index of any…

Functional Analysis · Mathematics 2017-06-06 Ryan M Causey

Large deviation estimates are by now a standard tool inthe Asymptotic Convex Geometry, contrary to small deviationresults. In this note we present a novel application of a smalldeviations inequality to a problem related to the diameters of…

Functional Analysis · Mathematics 2016-12-23 Bo'az Klartag , Roman Vershynin

We give theorems that can be used to upper bound the densities of packings of different spherical caps in the unit sphere and of translates of different convex bodies in Euclidean space. These theorems extend the linear programming bounds…

Metric Geometry · Mathematics 2014-09-26 David de Laat , Fernando Mario de Oliveira Filho , Frank Vallentin

We give upper and lower bounds for the ratio of the volume of metric ball to the area of the metric sphere in Finsler-Hadamard manifolds with pinched S-curvature. We apply these estimates to find the limit at the infinity for this ratio.…

Differential Geometry · Mathematics 2011-10-11 Alexandr A. Borisenko , Eugeny A. Olin

For a countable ordinal a we denote by C_a the class of separable, reflexive Banach spaces whose Szlenk index and the Szlenk index of their dual are bounded by a. We show that each C_a admits a separable, reflexive universal space. We also…

Functional Analysis · Mathematics 2007-06-06 Edward Odell , Thomas Schlumprecht , András Zsák

We give an explicit computation of the Banach envelope for the Paley-Wiener type spaces $E^p, 0<p<1$. This answers a question by Joel Shapiro.

Functional Analysis · Mathematics 2007-05-23 Mark Hoffmann

In this paper, we investigate the properties of the Mordukhovich derivatives of the metric projection operator onto closed balls, closed and convex cylinders and positive cones in uniformly convex and uniformly smooth Banach spaces. We find…

Functional Analysis · Mathematics 2024-01-23 Jinlu Li

We investigate elementary properties of successive radii in generalized Minkowski spaces (that is, with respect to gauges), i.e., we measure the "size" of a given convex set in a finite-dimensional real vector space with respect to another…

Metric Geometry · Mathematics 2015-04-14 Thomas Jahn

We study the problem of an appropriate choice of derivatives associated with discrete Fourier-Bessel expansions. We introduce a new so-called essential measure Fourier-Bessel setting, where the relevant derivative is simply the ordinary…

Classical Analysis and ODEs · Mathematics 2022-09-09 Bartosz Langowski , Adam Nowak

We obtain boundedness for the bilinear spherical maximal function in a range of exponents that includes the Banach triangle and a range of $L^p$ with $p<1$. We also obtain counterexamples that are asymptotically optimal with our positive…

Classical Analysis and ODEs · Mathematics 2017-04-13 J. A. Barrionevo , Loukas Grafakos , Danqing He , Petr Honzík , Lucas Oliveira

For $\mathbb B^n$ the unit ball of $\mathbb C^n$, we consider Bergman-Orlicz spaces of holomorphic functions in $L^\Phi_\alpha$, which are generalizations of classical Bergman spaces. We characterize the dual space of large Bergman-Orlicz…

Classical Analysis and ODEs · Mathematics 2015-01-15 Benoit F. Sehba , Edgar Tchoundja