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Related papers: On the space of Fredholm operators

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We present two applications of explicit formulas, due to Cuntz and Krieger, for computations in K-homology of graph C*-algebras. We prove that every K-homology class for such an algebra is represented by a Fredholm module having finite-rank…

Operator Algebras · Mathematics 2015-06-24 Tyrone Crisp

We prove the Fredholm alternative for a class of two-dimensional first-order hyperbolic systems with periodic-Dirichlet boundary conditions. Our approach is based on a regularization via a right parametrix.

Analysis of PDEs · Mathematics 2025-12-10 Irina Kmit

We survey recent progress in a program aimed at proving general Fatou-type results and establishing the well-posedness of a variety of boundary value problems in the upper half-space ${\mathbb{R}}^n_{+}$ for second-order, homogeneous,…

Analysis of PDEs · Mathematics 2020-08-13 José María Martell , Dorina Mitrea , Irina Mitrea , Marius Mitrea

We introduce Besov and Triebel--Lizorkin spaces on a manifold with boundary adapted to H\"ormander vector fields, near a so-called non-characteristic point of the boundary. We prove sharp results in these spaces for the corresponding…

Analysis of PDEs · Mathematics 2026-02-05 Brian Street

Toeplitz operators on spaces $H^p(G)\ (1< p<\infty)$ associated with compact connected Abelian group $G$ with ordered dual are considered and the generalization of the classical Gohberg-Krein theorem on the Fredholm index of such operators…

Functional Analysis · Mathematics 2019-12-10 A. R. Mirotin

We describe a very general (nonlinear) Fredholm theory for a new class of ambient spaces, called polyfolds. This theory is applicable to Gromov-Witten and Floer Theory as well as Symplectic Field Theory. It should also be applicable to a…

Symplectic Geometry · Mathematics 2007-05-23 Helmut H. Hofer

Several mathematicians, including myself, have studied some unifications in general topological spaces as well as in fuzzy topological spaces. For instance in our earlier works, using operations on topological spaces, we have tried to unify…

General Topology · Mathematics 2008-02-08 T. Hatice Yalvac

Semigroups generated by topological operations such as closure, interior or boundary are considered. It is noted that some of these semigroups are in general finite and noncommutative. The problem is formulated whether they are always…

General Mathematics · Mathematics 2008-05-13 Elemer E Rosinger

This paper concerns hyperbolic systems of two linear first-order PDEs in one space dimension with periodicity conditions in time and reflection boundary conditions in space. The coefficients of the PDEs are supposed to be time independent,…

Analysis of PDEs · Mathematics 2025-12-10 Irina Kmit , Lutz Recke

The topology of spaces of Hermitian operators in $C^n$ with non-simple spectra was studied by V.Arnold in a relation with the theory of adiabatic connections and the quantum Hall effect. The natural filtration of these spaces by the sets of…

Algebraic Topology · Mathematics 2014-07-29 Victor A. Vassiliev

We give explicit Fredholm conditions for classes of pseudodifferential operators on suitable singular and non-compact spaces. In particular, we include a "user's guide" to Fredholm conditions on particular classes of manifolds including…

Operator Algebras · Mathematics 2017-03-24 Catarina Carvalho , Victor Nistor , Yu Qiao

We establish local interval bifurcation theorem and global interval bifurcation theorem for Fredholm operator with index $0$ via $0$-group. As one of applications, we investigate the existence of a family of nontrivial domains…

Analysis of PDEs · Mathematics 2025-07-22 Guowei Dai , Yong Zhang

We study and compare the gap and the Riesz topologies of the space of all unbounded regular operators on Hilbert C*-modules. We show that the space of all bounded adjointable operators on Hilbert C*-modules is an open dense subset of the…

Operator Algebras · Mathematics 2009-01-15 Kamran Sharifi

We discuss several natural metrics on spaces of unbounded self--adjoint operators and their relations, among them the Riesz and the graph metric. We show that the topologies of the spaces of Fredholm operators resp. invertible operators…

Functional Analysis · Mathematics 2007-05-23 Matthias Lesch

For systems of ordinary differential equations on a compact interval, we study the character of solvability of the most general linear boundary-value problems in Sobolev spaces. We find the indices of these problems and obtain a criterion…

Classical Analysis and ODEs · Mathematics 2019-10-22 Olena Atlasiuk , Vladimir Mikhailets

This is a companion to recent papers of the authors; here we construct the `noncommutative Shilov boundary' of a (possibly nonunital) selfadjoint ordered space of Hilbert space operators. The morphisms in the universal property of the…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Kay Kirkpatrick , Matthew Neal , Wend Werner

We present the set of axioms for topological space with the operation of boundary as primitive notion.

General Topology · Mathematics 2007-05-23 K. Leśniak

In this paper a definition is given for an unbounded Toeplitz-like operator with rational symbol which has poles on the unit circle. It is shown that the operator is Fredholm if and only if the symbol has no zeroes on the unit circle, and a…

Functional Analysis · Mathematics 2020-02-21 G. J. Groenewald , S. ter Horst , J. Jaftha , A. C. M. Ran

On filtered manifolds one can define a different notion of order for the differential operators. In this paper, we use generalized fixed point algebras to construct a pseudodifferential extension that reflects this behaviour. In the…

Operator Algebras · Mathematics 2025-01-13 Eske Ewert

We study a natural family of non-local elliptic boundary problems on a compact oriented surface $\Sigma$ parametrized by the moduli space $\mathcal{M}_\Sigma$ of flat $G$-connections with framing along $\partial \Sigma$. This family…

Symplectic Geometry · Mathematics 2023-04-12 Yiannis Loizides