Results 1 to 10 of about 30,405 (240)
Toeplitz operators and Wiener-Hopf factorisation: an introduction
Concrete Operators, 2017 Wiener-Hopf factorisation plays an important role in the theory of Toeplitz operators. We consider here Toeplitz operators in the Hardy spaces Hp of the upper half-plane and we review how their Fredholm properties can be studied in terms of a Wiener-Hopf
Câmara M. Cristina
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On non-adjointable semi-Weyl and semi-B-Fredholm operators over C*-algebras
Banach Journal of Mathematical Analysis, 2021 We extend further semi-A-Fredholm theory by generalizing the results from classical semi-Weyl theory on Hilbert spaces. Moreover, we obtain an analogue of the results from [17] in the setting of non-adjointable operators.
Ivkovic, Stefan
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Perturbation Ideals and Fredholm Theory in Banach Algebras
Extracta Mathematicae, 2022 In this paper we characterize perturbation ideals of sets that generate the familiar spectra in Fredholm theory.
Tshikhudo Lukoto, Heinrich Raubenheimer
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A general Fredholm theory III: Fredholm functors and polyfolds [PDF]
Geometry & Topology, 2009 We describe a very general (nonlinear) Fredholm theory for a new class of ambient spaces, called polyfolds. The basic feature of these new spaces is that in general they may have locally varying dimensions. These new spaces are needed for a functional analytic treatment of nonlinear problems involving analytic limiting behavior.
Hofer, Helmut +2 more
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Polyfolds and Fredholm Theory [PDF]
, 2014 We describe a (nonlinear) Fredholm theory for a new class of ambient spaces, as well as for a certain type of categories. The theory is illustrated by an application to the category of stable maps.
Helmut Hofer
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Bifurcation theory for Fredholm operators
Journal of Differential EquationsThis paper consists of four parts. It begins by using the authors's generalized Schauder formula, [50], and the algebraic multiplicity, $χ$, of Esquinas and López-Gómez [18,17,40] to package and sharpening all existing results in local and global bifurcation theory for Fredholm operators through the recent author's axiomatization of the Fitzpatrick ...
Julián López-Gómez +1 more
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Fredholm theory for cofinite sets [PDF]
, 2015 We investigate two ways in which self-maps of an infinite set may be close to bijections; our investigation generates a $\mathbb{Z}$-valued index theory and a corresponding extension by $\mathbb{Z}$ for the quotient of the full symmetric group by its finitary subgroup.
P. L. Robinson
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A note on preservation of spectra for two given operators [PDF]
Mathematica Bohemica, 2020 We study the relationships between the spectra derived from Fredholm theory corresponding to two given bounded linear operators acting on the same space.
Carlos Carpintero +3 more
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Fredholm theory for demicompact linear relations
Applied General Topology, 2022 We first attempt to determine conditions on a linear relation T such that μT becomes a demicompact linear relation for each μ ∈ [0,1)(see Theorems 2.4 and 2.5).
Aymen Ammar, Slim Fakhfakh, Aref Jeribi
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A degree theory for locally compact perturbations of Fredholm maps in Banach spaces
Abstract and Applied Analysis, 2006 We present an integer valued degree theory for locally compact perturbations of Fredholm maps of index zero between (open sets in) Banach spaces (quasi-Fredholm maps, for short). The construction is based on the Brouwer degree theory and on the notion of
Pierluigi Benevieri, Massimo Furi
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