English
Related papers

Related papers: A note on Hausdorff-convergence of pseudospectra

200 papers

This paper delves into several characterizations of $A$-approximate point spectrum of A-bounded operators acting on a complex semi-Hilbertian space $H$ and also investigates properties of the $A$-approximate point spectrum for the tensor…

Functional Analysis · Mathematics 2024-03-11 Arup Majumdar , P. Sam Johnson

We study ordinal-indexed, multi-layer iterations of bounded operator transforms and prove convergence to spectral/ergodic projections under functional-calculus hypotheses. For normal operators on Hilbert space and polynomial or holomorphic…

Functional Analysis · Mathematics 2025-08-11 Faruk Alpay , Taylan Alpay , Hamdi Alakkad

We discuss some necessary and some sufficient conditions for an elementary operator $x\mapsto\sum_{i=1}^n a_ixb_i$ on a Banach algebra $A$ to be spectrally bounded. In the case of length three, we obtain a complete characterisation when $A$…

Functional Analysis · Mathematics 2013-12-23 Nadia Boudi , Martin Mathieu

The duality of uniform approximation property for Banach spaces is well known. In this note, we establish, under the assumption of local reflexivity, the duality of uniform approximation property in the category of operator spaces.

Operator Algebras · Mathematics 2014-10-28 Yanqi Qiu

In this paper we study a bounded domain with a small hole removed. Our main result concerns the spectrum of the Laplace operator with the Robin conditions imposed at the hole boundary. Moreover we prove that under some suitable assumptions…

Spectral Theory · Mathematics 2023-04-07 Diana Barseghyan , Baruch Schneider

We give the sharp conditions for boundedness of Hausdorff operators on certain modulation and Wiener amalgam spaces.

Classical Analysis and ODEs · Mathematics 2018-11-14 Guoping Zhao , Dashan Fan , Weichao Guo

We characterize the $L^1(E;\mu_\infty)$-spectrum of the Ornstein-Uhlenbeck operator, where $\mu_\infty$ is the invariant measure for the Ornstein-Uhlenbeck semigroup. The main result covers the general case of an infinite-dimensional Banach…

Classical Analysis and ODEs · Mathematics 2012-10-05 Rostyslav Kozhan

We study periodic approximations of aperiodic Schr\"odinger operators on lattices in Lie groups with dilation structure. The potentials arise through symbolic substitution systems that have been recently introduced in this setting. We…

Spectral Theory · Mathematics 2025-02-18 Ram Band , Siegfried Beckus , Felix Pogorzelski , Lior Tenenbaum

Let ${\mathcal B}(H)$ denote the Banach algebra of all bounded linear operators on a complex Hilbert space $H$ with $\dim H\geq 3$, and let $\mathcal A$ and $\mathcal B$ be subsets of ${\mathcal B}(H)$ which contain all rank one operators.…

Functional Analysis · Mathematics 2017-05-01 Jianlian Cui , Chi-Kwong Li , Nung-Sing Sze

We define new symbol classes for pseudodifferntial operators and investigate their pseudodifferential calculus. The symbol classes are parametrized by commutative convolution algebras. To every solid convolution algebra over a lattice we…

Functional Analysis · Mathematics 2010-12-21 Karlheinz Gröchenig , Ziemowit Rzeszotnik

In this paper, we consider the problem of approximating the spectral distribution for a class of random operators over sofic groups. For this purpose, we make use of the concept of locally and empirically converging measures defined by…

Spectral Theory · Mathematics 2026-03-03 Miguel Donoso-Echenique , Felix Pogorzelski , Michael Schrödl-Baumann

We obtain sharp approximation results for into nearisometries between Lp spaces and nearisometries into a Hilbert space. Our main theorem is the optimal approximation result for nearsurjective nearisometries between general Banach spaces.

Functional Analysis · Mathematics 2007-05-23 Peter Semrl , Jussi Vaisala

Given an operator ideal I, a Banach space E has the I-approximation property if operators on E can be uniformly approximated on compact subsets of E by operators belonging to I. In this paper the I- approximation property is studied in…

Functional Analysis · Mathematics 2010-09-16 Sonia Berrios , Geraldo Botelho

We show that for a very wide class of Banach spaces of functions on [0,1] there are intrinsic lower bounds for the essential spectral radius of the transfer operator associated to piecewise smooth expanding maps. The class of Banach spaces…

Dynamical Systems · Mathematics 2025-06-10 Oliver Butterley , Daniel Smania

In this paper we present some spectral property for quotient bounded operators and locally bounded operators on locally convex spaces. We introduce the spectral radius of a quotient bounded operator and we show that the Gelfand formula for…

Functional Analysis · Mathematics 2007-05-23 Mirel Sorin Stoian

A quasi-product on the normed space is defined. In addition, the notions of the eigenvectors of a linear operator can be extended for the nonlinear operator. Based on the quasi-product and the generalized eigenvectors, the spectral theorems…

Functional Analysis · Mathematics 2020-02-18 Wen Hsiang Wei

We construct non-random bounded discrete half-line Schr\" odinger operators which have purely singular continuous spectral measures with fractional Hausdorff dimension (in some interval of energies). To do this we use suitable sparse…

Mathematical Physics · Physics 2007-05-23 Andrej Zlatos

We establish sharp well-posedness and approximation estimates for variational saddle point systems at the continuous level. The main results of this note have been known to be true only in the finite dimensional case. Known spectral results…

Numerical Analysis · Mathematics 2014-11-04 Constantin Bacuta

A partially hyperbolic dynamical system is said to have the quasi-shadowing property if every pseudotrajectory can be shadowed by a sequence of points $(x_n)_{n\in \Z}$ such that $x_{n+1}$ is obtained from the image of $x_n$ by moving it by…

Dynamical Systems · Mathematics 2020-10-20 Lucas Backes , Davor Dragicevic

We consider the directed Hausdorff distance between point sets in the plane, where one or both point sets consist of imprecise points. An imprecise point is modelled by a disc given by its centre and a radius. The actual position of an…

Computational Geometry · Computer Science 2009-09-30 Christian Knauer , Maarten Löffler , Marc Scherfenberg , Thomas Wolle