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Related papers: A note on Hausdorff-convergence of pseudospectra

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In this paper, we investigate power-bounded operators, including surjective isometries, on Banach spaces. Koehler and Rosenthal asserted that an isolated point in the spectrum of a surjective isometry on a Banach space lies in the point…

Functional Analysis · Mathematics 2025-01-07 Shiho Oi , Jyamira Oppekepenguin

We design an abstract setting for the approximation in Banach spaces of operators acting in duality. A typical example are the gradient and divergence operators in Lebesgue--Sobolev spaces on a bounded domain. We apply this abstract setting…

Numerical Analysis · Mathematics 2018-06-28 Jérôme Droniou , Robert Eymard , T. Gallouët , R. Herbin

This paper is focused on some properties of paramonotone operators on Banach spaces and their application to certain feasibility problems for convex sets in a Hilbert space and convex systems in the Euclidean space. In particular, it shows…

Optimization and Control · Mathematics 2023-07-04 J. Camacho , M. J. Cánovas , J. E. Martínez-Legaz , J. Parra

We introduce compactness classes of Hilbert space operators by grouping together all operators for which the associated singular values decay at a certain speed and establish upper bounds for the norm of the resolvent of operators belonging…

Spectral Theory · Mathematics 2020-05-29 Ayse Guven , Oscar F. Bandtlow

A bounded operator $T$ in a Banach space $X$ is said to satisfy the essential descent spectrum equality, if the descent spectrum of $T$ as an operator on $X$ coincides with the essential descent spectrum of $T$. In this note, we give some…

Spectral Theory · Mathematics 2018-01-31 Abdelaziz Tajmouati , Hamid Boua

We introduce Hausdorff operators over the unit disc and give conditions for boundedness of such operator in Bloch, Bergman, and Hardy spaces on the disc. Identity approximation by Hausdorff operators is also considered.

Functional Analysis · Mathematics 2021-01-14 A. R. Mirotin

A lower semi-definite self-adjoint linear operator in a Hilbert space is taken whose discrete spectrum is not empty and comprises at least several eigenvalues $\lambda_{min}=\lambda_1\leqslant\ldots\leqslant\lambda_m<\sigma_{ess}$. The…

Spectral Theory · Mathematics 2019-02-19 Ruslan Sharipov

Resonances, isolated eigenvalues of a transfer operator acting on suitably chosen Banach spaces, play a fundamental role in understanding the statistical properties of chaotic dynamical systems. In this paper, we introduce a pseudospectral…

Dynamical Systems · Mathematics 2025-07-15 Alex Blumenthal , Isaia Nisoli , Toby Taylor-Crush

We consider the Schroedinger operator with a complex delta interaction supported by two parallel hypersurfaces in the Euclidean space of any dimension. We analyse spectral properties of the system in the limit when the distance between the…

Mathematical Physics · Physics 2017-09-07 Sylwia Kondej , David Krejcirik

It is known that any separable Banach space with BAP is a complemented subspace of a Banach space with a basis. We show that every operator with bounded approximation property, acting from a separable Banach space, can be factored through a…

Functional Analysis · Mathematics 2013-12-10 Oleg Reinov

We study Birkhoff-James orthogonality and isosceles orthogonality of bounded linear operators between Hilbert spaces and Banach spaces. We explore Birkhoff-James orthogonality of bounded linear operators in light of a new notion introduced…

Functional Analysis · Mathematics 2020-04-28 Tamara Bottazzi , Cristian Conde , Debmalya Sain

We study the asymptotic behavior of a bounded solution of an inhomogeneous delay linear difference equation in a Banach space by using the spectrum of bounded sequences. We get a significant extension of excellent results in [1]. A new…

General Mathematics · Mathematics 2015-09-01 Dang Vu Giang

We give a review of results on the operator-norm convergence of the Trotter product formula on Hilbert and Banach spaces, which is focused on the problem of its convergence rates. Some recent results concerning evolution semigroups are…

Functional Analysis · Mathematics 2020-02-12 Hagen Neidhardt , Artur Stephan , Valentin Zagrebnov

We show examples of compact linear operators between Banach spaces which cannot be approximated by norm attaining operators. This is the negative answer to an open question posed in the 1970's. Actually, any strictly convex Banach space…

Functional Analysis · Mathematics 2014-07-16 Miguel Martin

It is well known that iterates of quasi-compact operators converge towards a spectral projection, whereas the explicit construction of the limiting operator is in general hard to obtain. Here, we show a simple method to explicitly construct…

Functional Analysis · Mathematics 2017-06-05 Johannes Nagler

In this work we construct certain general bundles $<\mathfrak{M},\rho,X>$ and $<\mathfrak{B},\eta,X>$ of Hausdorff locally convex spaces associated with a given Banach bundle $<\mathfrak{E},\pi,X>$. Then we present conditions ensuring the…

Functional Analysis · Mathematics 2021-10-22 Benedetto Silvestri

We consider the problem of variation of spectral subspaces for linear self-adjoint operators under off-diagonal perturbations. We prove a number of new optimal results on the shift of the spectrum and obtain (sharp) estimates on the norm of…

Spectral Theory · Mathematics 2007-07-23 Vadim Kostrykin , Konstantin A. Makarov , Alexander K. Motovilov

In this paper, we report on new results related to the existence of an adjoint for operators on separable Banach spaces and discuss a few interesting applications. (Some results are new even for Hilbert spaces.) Our first two applications…

Mathematical Physics · Physics 2010-10-26 Tepper L Gill , Francis Mensah , Woodford W. Zachary

In this paper, we introduce the Hausdorff operator associated with the Opdam--Cherednik transform and study the boundedness of this operator in various Lebesgue spaces. In particular, we prove the boundedness of the Hausdorff operator in…

Functional Analysis · Mathematics 2022-06-07 Shyam Swarup Mondal , Anirudha Poria

In this paper we show that a result of Gross and Kuelbs, used to study Gaussian measures on Banach spaces, makes it possible to construct an adjoint for operators on separable Banach spaces. This result is used to extend well known theorems…

Mathematical Physics · Physics 2007-05-23 T. L. Gill , S. Basu , W. W. Zachary , V. Steadman