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Related papers: The Witten index and the spectral shift function

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Let $\Gamma$ be a compact group acting on a smooth, compact manifold $M$, let $P \in \psi^m(M; E_0, E_1)$ be a $\Gamma$-invariant, classical pseudodifferential operator acting between sections of two equivariant vector bundles $E_i \to M$,…

Differential Geometry · Mathematics 2020-10-01 A. Baldare , R. Côme , M. Lesch , V. Nistor

We consider generalised Dirac--Schr\"odinger operators, consisting of a self-adjoint elliptic first-order differential operator D with a skew-adjoint 'potential' given by a (suitable) family of unbounded operators. The index of such an…

K-Theory and Homology · Mathematics 2025-01-29 Koen van den Dungen

The minimal operator and the maximal operator of an elliptic pseudo-differential operator with symbols on $\Z^n\times \mathbb{T}^n$ are proved to coincide and the domain is given in terms of a Sobolev space. Ellipticity and Fredholmness are…

Spectral Theory · Mathematics 2019-10-22 Aparajita Dasgupta , Vishvesh Kumar

We derive a decomposition formula for the spectral flow of a 1-parameter family of self-adjoint Dirac operators on an odd-dimensional manifold $M$ split along a hypersurface $\Sigma$ ($M=X\cup_{\Sigma} Y$). No transversality or stretching…

Differential Geometry · Mathematics 2007-05-23 M. Daniel , P. Kirk

In this paper we introduce a notion of scattering theory for the Laplace-Beltrami operator on non-compact, connected and complete Riemannian manifolds. A principal condition is given by a certain positive lower bound of the second…

Mathematical Physics · Physics 2011-09-12 K. Ito , E. Skibsted

This paper is devoted to the definition and analysis of the spectral shift function (SSF) associated with non-self-adjoint perturbations of self-adjoint operators. Motivated by applications in scattering theory, we consider both trace-class…

Mathematical Physics · Physics 2026-03-24 Vincent Bruneau , Nicolas Frantz , François Nicoleau

We study the pseudospectrum of a class of non-selfadjoint differential operators. Our work consists in a detailed study of the microlocal properties, which rule the spectral stability or instability phenomena appearing under small…

Analysis of PDEs · Mathematics 2007-05-23 Karel Pravda-Starov

We investigate the problem of calculating the Fredholm index of a geometric Dirac operator subject to local (e.g. Dirichlet and Neumann) and non-local (APS) boundary conditions posed on the strata of a manifold with corners. The boundary…

Analysis of PDEs · Mathematics 2017-04-11 Karsten Bohlen

This paper presents the Fredholm theory on l^p-spaces for band-dominated operators and important subclasses, such as operators in the Wiener algebra. It particularly closes several gaps in the previously known results for the case p=\infty…

Functional Analysis · Mathematics 2015-11-23 Markus Seidel

We investigate trace formulas for one-dimensional Schroedinger operators which are trace class perturbations of quasi-periodic finite-gap operators using Krein's spectral shift theory. In particular, we establish the conserved quantities…

Spectral Theory · Mathematics 2012-04-03 Alice Mikikits-Leitner , Gerald Teschl

We prove equivariant spectral asymptotics for $ h$-pseudodifferential operators for compact orthogonal group actions generalizing results of El-Houakmi and Helffer (1991) and Cassanas (2006). Using recent results for certain oscillatory…

Mathematical Physics · Physics 2014-12-12 Tobias Weich

We review the definition of a Lie manifold $(M, \VV)$ and the construction of the algebra $\Psi\sp{\infty}\sb{\VV}(M)$ of pseudodifferential operators on a Lie manifold $(M, \VV)$. We give some concrete Fredholmness conditions for…

Analysis of PDEs · Mathematics 2025-10-20 Victor Nistor

Inserting a magnetic flux into a two-dimensional one-particle Hamiltonian leads to a spectral flow through a given gap which is equal to the Chern number of the associated Fermi projection. This paper establishes a generalization to higher…

Mathematical Physics · Physics 2018-11-30 Alan L. Carey , Hermann Schulz-Baldes

We study the heat trace for both the drifting Laplacian as well as Schr\"odinger operators on compact Riemannian manifolds. In the case of a finite regularity potential or weight function, we prove the existence of a partial (six term)…

Differential Geometry · Mathematics 2020-12-11 Nelia Charalambous , Julie Rowlett

Koopman operator theory enables linear analysis of nonlinear dynamical systems by lifting their evolution to infinite-dimensional function spaces. However, finite-dimensional approximations of Koopman and transfer (Frobenius--Perron)…

Dynamical Systems · Mathematics 2025-07-24 April Herwig , Matthew J. Colbrook , Oliver Junge , Péter Koltai , Julia Slipantschuk

It is well known that elliptic operators on a smooth compact manifold are classified by K-homology. We prove that a similar classification is also valid for manifolds with simplest singularities: isolated conical points and fibered…

Operator Algebras · Mathematics 2007-05-23 A. Savin

The geometry of dynamical systems estimated from trajectory data is a major challenge for machine learning applications. Koopman and transfer operators provide a linear representation of nonlinear dynamics through their spectral…

Machine Learning · Statistics 2025-09-30 Thibaut Germain , Rémi Flamary , Vladimir R. Kostic , Karim Lounici

This work is a continuation and extension of the note published in the Russian Math Surveys 1997 n 6. For any pair of solutions of the spectral problem for the second order selfadjoint real Schrodinger Operator on the graph their Symplectic…

Mathematical Physics · Physics 2007-05-23 S. P. Novikov

We show that the Dirac operator on a compact globally hyperbolic Lorentzian spacetime with spacelike Cauchy boundary is a Fredholm operator if appropriate boundary conditions are imposed. We prove that the index of this operator is given by…

Differential Geometry · Mathematics 2019-10-01 Christian Baer , Alexander Strohmaier

We prove sharp lower bounds on the spectral gap of 1-dimensional Schr\"odinger operators with Robin boundary conditions for each value of the Robin parameter. In particular, our lower bounds apply to single-well potentials with a centered…

Spectral Theory · Mathematics 2020-06-02 Mark S. Ashbaugh , Derek Kielty