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Related papers: Spectral flow for nonunital spectral triples

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A formula is given in terms of secondary characteristic classes for the leading order contribution to the spectral flow for a path of twisted Dirac operators on an odd dimensional, Riemannian manifold when the twisting is done by a path of…

Differential Geometry · Mathematics 2007-05-23 Clifford Henry Taubes

We define a spectral flow for paths of selfadjoint Fredholm operators that are equivariant under the orthogonal action of a compact Lie group as an element of the representation ring of the latter. This $G$-equivariant spectral flow shares…

Functional Analysis · Mathematics 2021-04-06 Marek Izydorek , Joanna Janczewska , Nils Waterstraat

We give a comprehensive account of an analytic approach to spectral flow along paths of self-adjoint Breuer-Fredholm operators in a type $I_{\infty}$ or $II_\infty$ von Neumann algebra ${\mathcal N}$. The framework is that of {\it odd…

K-Theory and Homology · Mathematics 2007-05-23 Alan L. Carey , John Phillips

We study the index theory for actions of compact Lie groups on C*-algebras with an emphasis on principal actions. Given an invariant semifinite trace on the C*-algebra we obtain semifinite spectral triples. For circle actions we consider…

K-Theory and Homology · Mathematics 2008-06-28 Charlotte Wahl

The spectra of parallel flows (that is, flows governed by first-order differential operators parallel to one direction) are investigated, on both $L^2$ spaces and weighted-$L^2$ spaces. As a consequence, an example of a flow admitting a…

Spectral Theory · Mathematics 2013-10-29 Jonathan Ben-Artzi

We establish a splitting formula for the spectral flow of the odd signature operator on a closed 3-manifold M coupled to a path of SU(2) connections, provided M = S cup X, where S is the solid torus. It describes the spectral flow on M in…

Geometric Topology · Mathematics 2014-11-11 Benjamin Himpel

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

This paper continues the previous work (Quantum Inf. Process (2019)) by two authors of the present paper about a spectral mapping property of chiral symmetric unitary operators. In physics, they treat non-unitary time-evolution operators to…

Mathematical Physics · Physics 2022-09-28 Keisuke Asahara , Daiju Funakawa , Etsuo Segawa , Akito Suzuki , Noriaki Teranishi

We prove a spectral flow formula for one-parameter families of Hamiltonian systems under homoclinic boundary conditions, which relates the spectral flow to the relative Maslov index of a pair of curves of Lagrangians induced by the stable…

Dynamical Systems · Mathematics 2017-05-17 Nils Waterstraat

We show that the principle "nonvanishing of spectral flow of the linearization along the trivial branch entails bifurcation of nontrivial solutions ", proved in \cite{FPR} for critical points of one parameter families of $C^2$ functionals…

Analysis of PDEs · Mathematics 2024-01-25 J. Pejsachowicz

We construct spectral triples on C*-algebraic extensions of unital C*-algebras by stable ideals satisfying a certain Toeplitz type property using given spectral triples on the quotient and ideal. Our construction behaves well with respect…

Operator Algebras · Mathematics 2016-08-29 Andrew Hawkins , Joachim Zacharias

We consider families of strongly indefinite systems of elliptic PDE and investigate bifurcation from a trivial branch of solutions by using the spectral flow. The novelty in our approach is a refined version of a comparison principle that…

Analysis of PDEs · Mathematics 2024-08-14 J. Janczewska , M. Möckel , N. Waterstraat

We consider bifurcation of critical points from a trivial branch for families of functionals that are invariant under the orthogonal action of a compact Lie group. Based on a recent construction of an equivariant spectral flow by the…

Functional Analysis · Mathematics 2023-06-05 Marek Izydorek , Joanna Janczewska , Maciej Starostka , Nils Waterstraat

For any set $M$ of natural numbers there are mixing Gaussian automorphisms and non-mixing Gaussian automorphisms with singular spectrum (as well as some automorphisms which are disjoint from all Gaussian actions) such that $…

Dynamical Systems · Mathematics 2014-07-01 V. V. Ryzhikov

Using associated trees, we construct a spectral triple for the C$^*$-algebra of continuous functions on the ring of integers $R$ of a nonarchimedean local field $F$ of characteristic zero, and investigate its properties. Remarkably, the…

Operator Algebras · Mathematics 2016-12-13 Slawomir Klimek , Sumedha Rathnayake , Kaoru Sakai

We introduce the notion of spectral flow along a periodic semi-Riemannian geodesic, as a suitable substitute of the Morse index in the Riemannian case. We study the growth of the spectral flow along a closed geodesic under iteration,…

Differential Geometry · Mathematics 2007-11-06 Miguel Angel Javaloyes , Paolo Piccione

We analyze the action of the spectral flows on N=2 twisted topological theories. We show that they provide a useful mapping between the two twisted topological theories associated to a given N=2 superconformal theory. This mapping can also…

High Energy Physics - Theory · Physics 2011-07-19 Beatriz Gato-Rivera , Jose Ignacio Rosado

Using spectral flow, we provide a proof of [11, Theorem 9.17] on unitarity of Ramond twisted non-extremal representations of unitary minimal $W$-algebras that does not rely on the still conjectural exactness of the twisted quantum reduction…

Representation Theory · Mathematics 2026-04-08 Victor G. Kac , Pierluigi Möseneder Frajria , Paolo Papi

We extend the spectral theory of commutative C*-categories to the non full-case, introducing a suitable notion of spectral spaceoid provinding a duality between a category of "non-trivial" *-functors of non-full commutative C*-categories…

Operator Algebras · Mathematics 2025-11-04 Paolo Bertozzini , Roberto Conti , Wicharn Lewkeeratiyutkul , Kasemsun Rutamorn

We consider AF-flows, i.e., one-parameter automorphism groups of a unital simple C*-algebra which leave invariant the dense union of an increasing sequence of finite-dimensional *-subalgebras, and derive two properties for these; an absence…

Operator Algebras · Mathematics 2009-10-31 Ola Bratteli , Akitaka Kishimoto