English
Related papers

Related papers: Dense Stable Rank and Runge Type Approximation The…

200 papers

Let A be a unital maximal full algebra of operator fields with base space the k-cube [0,1]^k and fibre algebras, say, {A_t}_{t \in [0,1]^k}. Then the stable rank of A is bounded above by the supremum of the stable ranks sr(C([0,1]^k)…

Operator Algebras · Mathematics 2007-05-23 Ping Wong Ng , Takahiro Sudo

Let $D, \Omega_1, ..., \Omega_m$ be irreducible bounded symmetric domains. We study local holomorphic maps from $D$ into $\Omega_1 \times... \Omega_m$ preserving the invariant $(p, p)$-forms induced from the normalized Bergman metrics up to…

Complex Variables · Mathematics 2015-03-03 Yuan Yuan

Let $\mathscr{C}_\mathbb{Z}([0,1])$ be the metric space of real-valued continuous functions on $[0,1]$ with integer values at $0$ and $1$, equipped with the uniform (supremum) metric $d_\infty$. It is a classical theorem in approximation…

Number Theory · Mathematics 2023-11-21 C. Sinan Güntürk , Weilin Li

Let $K$ be a closed polydisc or ball in $\C^n$, and let $Y$ be a quasi projective algebraic manifold which is Zariski locally equivalent to $\C^p$, or a complement of an algebraic subvariety of codimension $\ge 2$ in such manifold. If $r$…

Complex Variables · Mathematics 2007-05-23 Kolarič Dejan

We prove that functions continuous up to the boundary are dense in de Branges-Rovnyak spaces induced by extreme points the unit ball of $H^\infty$.

Functional Analysis · Mathematics 2017-04-07 Alexandru Aleman , Bartosz Malman

In this paper, first some results of [5] are extended for subadditive separating maps between C(X;E) and C(Y;E), such that E is a unital Banach algebra. Then we give some conditions under which a strongly subadditive map has a unique fixed…

Functional Analysis · Mathematics 2015-06-02 Yousef Estaremi , Bahman Moeini

Let $A$ be a Banach algebra, not necessarily unital, and let $B$ be a closed subalgebra of $A$. We establish a connection between the Banach cyclic cohomology group $ {\cal{HC}}^n(A)$ of $A$ and the Banach $B$-relative cyclic cohomology…

Operator Algebras · Mathematics 2020-04-28 Zinaida A. Lykova

In most classical holomorphic function spaces on the unit disk in which the polynomials are dense, a function $f$ can be approximated in norm by its dilates $f_r(z):=f(rz)~(r<1)$, in other words, $\lim_{r\to1^-}\|f_r-f\|=0$. We construct a…

Complex Variables · Mathematics 2019-02-18 Javad Mashreghi , Thomas Ransford

We define centrally large subalgebras of simple unital C*-algebras, strengthening the definition of large subalgebras in previous work. We prove that if A is any infinite dimensional simple separable unital C*-algebra which contains a…

Operator Algebras · Mathematics 2016-08-23 Dawn Archey , N. Christopher Phillips

Let $H$ be a Hilbert space that can be embedded as a dense subspace of a Banach space $X$ such that the norm of the embedding is equal to $1$. We consider the following statements for a nonzero vector $\varphi$ in $H$: (A) $\|\varphi\|_X =…

Functional Analysis · Mathematics 2024-07-01 Konstantinos Bampouras , Ole Fredrik Brevig

It is shown that a Banach space with locally uniformly convex dual admits an equivalent norm which is itself locally uniformly convex. It follows that on any such space all continuous real-valued functions may be uniformly approximated by…

Functional Analysis · Mathematics 2007-05-23 Richard Haydon

Models with nonlinear architectures/parameterizations such as deep neural networks (DNNs) are well known for their mysteriously good generalization performance at overparameterization. In this work, we tackle this mystery from a novel…

Machine Learning · Computer Science 2022-11-22 Yaoyu Zhang , Zhongwang Zhang , Leyang Zhang , Zhiwei Bai , Tao Luo , Zhi-Qin John Xu

Following the development of weighted asymptotic approximation properties of matrices, we introduce the analogous uniform approximation properties (that is, study the improvability of Dirichlet's Theorem). An added feature is the use of…

Number Theory · Mathematics 2022-02-25 Dmitry Kleinbock , Anurag Rao

We prove strict necessary density conditions for coherent frames and Riesz sequences on homogeneous groups. Let $N$ be a connected, simply connected nilpotent Lie group with a dilation structure (a homogeneous group) and let $(\pi,…

Functional Analysis · Mathematics 2022-05-04 Karlheinz Gröchenig , José Luis Romero , David Rottensteiner , Jordy Timo van Velthoven

The main purpose of this article is to establish new uniqueness results for Calder\'on type inverse problems related to damped nonlocal wave equations. To achieve this goal we extend the theory of very weak solutions to our setting, which…

Analysis of PDEs · Mathematics 2024-12-04 Philipp Zimmermann

In this paper we obtain an almost sure invariance principle for convergent sequences of either Anosov diffeomorphisms or expanding maps on compact Riemannian manifolds and prove an ergodic stability result for such sequences. The sequences…

Dynamical Systems · Mathematics 2017-09-07 A. Castro , F. B. Rodrigues , P. Varandas

We study the ergodic and statistical properties of a class of maps of the circle and of the interval of Lorenz type which present indifferent fixed points and points with unbounded derivative. These maps have been previously investigated in…

Dynamical Systems · Mathematics 2008-12-16 Giampaolo Cristadoro , Nicolai Haydn , Philippe Marie , Sandro Vaienti

Given an open subset $U$ of a complex Banach space $E$, a weight $v$ on $U$, and a complex Banach space $F$, let $\mathcal{H}^\infty_v(U,F)$ denote the Banach space of all weighted holomorphic mappings $f\colon U\to F$, under the weighted…

Functional Analysis · Mathematics 2024-08-27 M. G. Cabrera-Padilla , A. Jiménez-Vargas , A. Keten Çopur

Following Granirer, a Banach algebra A is extremely non-Arens regular when the quotient space A*/WAP(A) contains a closed linear subspace which has A* as a continuous linear image. We prove that the group algebra L^1(G) of any infinite…

Functional Analysis · Mathematics 2013-07-04 Mahmoud Filali , Jorge Galindo

The aim of this paper is twofold. On the one hand, we manage to identify Banach-valued Hardy spaces of analytic functions over the disc $\mathbb{D}$ with other classes of Hardy spaces, thus complementing the existing literature on the…

Functional Analysis · Mathematics 2024-09-10 Fernando Albiac , Jose L. Ansorena