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Related papers: Regular Fredholm Pairs

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The Fredholm property of Toeplitz operators on the $p$-Fock spaces $F_\alpha^p$ on $\mathbb{C}^n$ is studied. A general Fredholm criterion for arbitrary operators from the Toeplitz algebra $\mathcal{T}_{p,\alpha}$ on $F_\alpha^p$ in terms…

Functional Analysis · Mathematics 2018-11-09 Robert Fulsche , Raffael Hagger

In this paper, we discuss three short topics related to the parity operator and his role in quantum harmonic analysis. We derive results for the Fredholm index of even and odd operators, discuss operators on which the modulation action acts…

Functional Analysis · Mathematics 2026-03-30 Robert Fulsche

This paper is devoted to Fredholm realizations of semi-Fredholm operators in a Hilbert space. Such a realization is determined by an abstract boundary condition, which is a subspace of the space of abstract boundary values. We find the…

Differential Geometry · Mathematics 2024-01-30 Marina Prokhorova

The index of a selfadjoint Fredholm operator is zero by the well-known fact that the kernel of a selfadjoint operator is perpendicular to its range. The Fredholm index was generalised to families by Atiyah and J\"anich in the sixties, and…

Functional Analysis · Mathematics 2020-12-11 Robert Skiba , Nils Waterstraat

Withdrawn due to a likely error with the homeomorphism at line (4). Old abstract: In the monograph 'Limit Operators and their Applications in Operator Theory', the authors define the operator spectrum of a band-dominated operator T and…

Functional Analysis · Mathematics 2008-07-05 Rufus Willett

In this paper, we address the existence of Fredholm backstepping transformations for self-adjoint and skew-adjoint operators $A$. Under suitable assumptions on the operator $A$ and the possibly unbounded control operator $B$, we prove the…

Optimization and Control · Mathematics 2026-05-19 Ludovick Gagnon , Amaury Hayat , Swann Marx , Shengquan Xiang , Christophe Zhang

We study the composition of time-ffrequency localization operators (wavepacket operators) and develop a symbolic calculus of such operators on modulation spaces. The use of time-frequency methods (phase space methods) allows the use of…

Functional Analysis · Mathematics 2011-04-27 Elena Cordero , Karlheinz Gröchenig

This paper has aim to characterize Fredholmness and Weylness of upper triangular operator matrices having arbitrary dimension n. We present various characterization results in the setting of infinite dimensional Hilbert spaces, thus…

Functional Analysis · Mathematics 2025-08-27 Nikola Sarajlija

Denote by $T_n^d(A)$ an upper triangular operator matrix of dimension $n$ whose diagonal entries are given and the others are unknown. In this article we provide necessary and sufficient conditions for various types of Fredholm and Weyl…

Functional Analysis · Mathematics 2025-08-27 Nikola Sarajlija

We study compactness and the Fredholm property for linear operators on coorbit spaces over locally compact abelian phase spaces. In contrast to previous works, we do not impose any countability assumptions on the underlying groups. Our…

Functional Analysis · Mathematics 2025-11-25 Robert Fulsche , Raffael Hagger

Given an idempotent $p$ in a Banach algebra and following the study in \cite{P50} of p-invertibility, we consider here left p-invertibility, right p-invertibility and p-invertibility in the Calkin Algebra $\mathcal{C}(X),$ where $X$ is a…

Functional Analysis · Mathematics 2024-01-11 Alaa Hamdan , Mohammed Berkani

We present classical and generalized Riemann-Hilbert problem in several contexts arising from $K$-theory and bordism theory. The language of Fredholm pairs turns out to be useful and unavoidable. We propose an abstract formulation of a…

K-Theory and Homology · Mathematics 2007-05-23 Bogdan Bojarski , Andrzej Weber

An adjoint pair is a pair of densely defined linear operators $A, B$ on a Hilbert space such that $\langle Ax,y\rangle=\langle x,By\rangle$ for $x\in \cD(A), y \in \cD(B).$ We consider adjoint pairs for which $0$ is a regular point for both…

Functional Analysis · Mathematics 2021-11-29 Konrad Schmüdgen

We study some basic properties of the class of universal operators on Hilbert space, and provide new examples of universal operators and universal pairs.

Functional Analysis · Mathematics 2017-02-20 Riikka Schroderus , Hans-Olav Tylli

Naively, the analytic index of a family of self-adjoint Fredholm operators ought to be (an equivalence class of) the family of the kernels of these operators. The present paper is devoted to a rigorous version of this idea based on ideas of…

Differential Geometry · Mathematics 2023-02-09 Nikolai V. Ivanov

Asymmetric dual truncated Toeplitz operators acting between the orthogonal complements of two (eventually different) model spaces are introduced and studied. They are shown to be equivalent after extension to paired operators on…

Functional Analysis · Mathematics 2020-01-01 M. Cristina Câmara , Kamila Kliś-Garlicka , Bartosz Łanucha , Marek Ptak

We study linear boundary-value problems for systems of first-order ordinary differential equations with the most general boundary conditions in the normed spaces of continuously differentiable functions on a finite closed interval. The…

Classical Analysis and ODEs · Mathematics 2026-01-05 Vitalii Soldatov

The main topic is the development of a Fredholm theory in a new class of spaces called M-polyfolds. In the subsequent Volume II the theory will be generalized to an even larger class of spaces called polyfolds, which can also incorporate…

Functional Analysis · Mathematics 2014-07-14 Helmut H. Hofer , Kris Wysocki , Eduard Zehnder

Motivated by the dynamics of defects in planar pattern-forming systems, we study Fredholm properties of elliptic operators with singular coefficients in weighted Sobolev spaces. In particular, we consider a family of doubly weighted spaces…

Analysis of PDEs · Mathematics 2025-05-06 Gabriela Jaramillo

We study the stability of Fredholm property for regular operators on Hilbert $C^*$-modules under some certain perturbations. We treat this problem when perturbing operators are (relatively) bounded or relatively compact. We also consider…

Operator Algebras · Mathematics 2017-02-21 Marzieh Forough