English
Related papers

Related papers: Spectral flow, index and the signature operator

200 papers

We compute, in topological terms, the spectral flow of an arbitrary family of self-adjoint Dirac type operators with classical (local) boundary conditions on a compact Riemannian manifold with boundary under the assumption that the initial…

Analysis of PDEs · Mathematics 2012-10-08 M. I. Katsnelson , V. E. Nazaikinskii

Spectral flow was first studied by Atiyah and Lusztig, and first appeared in print in the work of Atiyah-Patodi-Singer (APS). For a norm-continuous path of self-adjoint Fredholm operators in the multiplier algebra $\mathcal{M}(\mathcal{B})$…

Operator Algebras · Mathematics 2024-01-12 Ping Wong Ng , Arindam Sutradhar , Cangyuan Wang

We prove two results about nonunital index theory left open by [CGRS2]. The first is that the spectral triple arising from an action of the reals on a C*-algebra with invariant trace satisfies the hypotheses of the nonunital local index…

K-Theory and Homology · Mathematics 2014-02-28 A. Carey , V. Gayral , J. Phillips , A. Rennie , F. Sukochev

We discuss the well known ``Fredholm index=spectral flow'' theorem and show that it can be interpreted as a limit case of an identity involving two spectral shift functions.

Spectral Theory · Mathematics 2007-11-02 Alexander Pushnitski

We consider families $A(t)$ of self-adjoint operators with symmetry that causes the spectral flow of the family to vanish. We study the secondary $\mathbb{Z}_2$-valued spectral flow of such families. We prove an analog of the…

Differential Geometry · Mathematics 2025-02-04 Maxim Braverman , Ahmad Reza Haj Saeedi Sadegh

We develop an index theory for variational problems on noncompact quantum graphs. The main results are a spectral flow formula, relating the net change of eigenvalues to the Maslov index of boundary data, and a Morse index theorem, equating…

Functional Analysis · Mathematics 2026-03-26 Daniele Garrisi , Alessandro Portaluri , Li Wu

In this paper, we define the spectral Einstein functional associated with the sub-signature operator for manifolds with boundary. Motivated by the spectral Einstein functional and the sub-signature operator, we relate them to the…

Differential Geometry · Mathematics 2023-11-08 Hongfeng Li , Yong Wang

Let M be an even dimensional compact Riemannian manifold with boundary and let D be a Dirac operator acting on the sections of the Clifford module E over M. We impose certain local elliptic boundary conditions for D obtaining a selfadjoint…

Analysis of PDEs · Mathematics 2017-03-10 Alexander Gorokhovsky , Matthias Lesch

We give a definition of the spectral flow for continuous paths in the space of bounded and essentially hyperbolic operators. We provide a homotopical characterization of the spectral flow in terms of a group homomorphism of the fundamental…

Functional Analysis · Mathematics 2010-05-11 Daniele Garrisi

Let $\{A(t)\}_{t \in \mathbb{R}}$ be a path of self-adjoint Fredholm operators in a Hilbert space $\mathcal{H}$, joining endpoints $A_\pm$ as $t \to \pm \infty$. Computing the index of the operator $D_A= (d/d t) + A$ acting in…

Spectral Theory · Mathematics 2015-09-08 Alan Carey , Fritz Gesztesy , Galina Levitina , Fedor Sukochev

We consider a continuous curve of linear elliptic formally self-adjoint differential operators of first order with smooth coefficients over a compact Riemannian manifold with boundary together with a continuous curve of global elliptic…

Differential Geometry · Mathematics 2014-06-04 Bernhelm Booss-Bavnbek , Chaofeng Zhu

We show that a recent spectral flow approach proposed by Berkolaiko-Cox-Marzuola for analyzing the nodal deficiency of the nodal partition associated to an eigenfunction can be extended to more general partitions. To be more precise, we…

Spectral Theory · Mathematics 2021-03-16 Bernard Helffer , Mikael Persson Sundqvist

In this article we study generalised Dirac-Schr\"odinger operators in arbitrary signatures (with or without gradings), providing a general KK-theoretic framework for the study of index pairings and spectral flow. We provide a general…

K-Theory and Homology · Mathematics 2025-09-30 Koen van den Dungen

We prove an integral formula for the spectral flow of differentiable loops of unitaries of the form ${\rm Id}+$Schatten. Our formula is in terms of a regularised winding number, expressed in terms of exact differential forms, and we show…

Functional Analysis · Mathematics 2026-04-27 A. Alexander , A. Carey , G. Levitina , A. Rennie

Using the notion of spectral flow, we suggest a simple approach to various asymptotic problems involving eigenvalues in the gaps of the essential spectrum of self-adjoint operators. Our approach uses some elements of the spectral shift…

Spectral Theory · Mathematics 2015-05-13 Alexander Pushnitski

We obtain general theorems which enable the calculation of the Dixmier trace in terms of the asymptotics of the zeta function and of the heat operator in a general semi-finite von Neumann algebra. Our results have several applications. We…

Operator Algebras · Mathematics 2007-05-23 Alan L Carey , John Phillips , Fyodor Sukochev

We consider Fourier integral operators with symbols in modulation spaces and non-smooth phase functions whose second orders of derivatives belong to certain types of modulation space. We establish continuity and Schatten-von Neumann…

Analysis of PDEs · Mathematics 2008-02-19 Joachim Toft , Francesco Concetti , Gianluca Garello

Spectral theory and functional calculus for unbounded self-adjoint operators on a Hilbert space are usually treated through von Neumann's Cayley transform. Based on ideas of Woronowicz, we redevelop this theory from the point of view of…

Operator Algebras · Mathematics 2016-09-14 Christian Budde , Klaas Landsman

Let~$H_0$ and~$V$ be self-adjoint operators such that~$V$ admits a factorisation $V = F^*JF$ with bounded self-adjoint $J$ and $|H_0|^{1/2}$-compact~$F.$ Flow of singular spectrum of the path of self-adjoint operators $H_0 + rV,$ $r \in…

Spectral Theory · Mathematics 2021-09-23 Nurula Azamov

This paper is devoted to the study of the spectral properties of Dirac operators on the three-sphere with singular magnetic fields supported on smooth, oriented links. As for Aharonov-Bohm solenoids in Euclidean three-space, the flux…

Mathematical Physics · Physics 2019-02-11 Fabian Portmann , Jérémy Sok , Jan Philip Solovej