English
Related papers

Related papers: The spectral localizer for even index pairings

200 papers

Let $\sigma$ be the involution of the Roe algebra $\Roe{\RR}$ which is induced from the reflection $\RR\to\RR; x\mapsto -x$. A graded Fredholm module over a separable $C^*$-algebra $A$ gives rise to a homomorphism…

K-Theory and Homology · Mathematics 2010-03-10 Robert Yuncken

A class of real spectral triples that are similar in structure to a Riemannian manifold but have a finite-dimensional Hilbert space is defined and investigated, determining a general form for the Dirac operator. Examples include fuzzy…

Mathematical Physics · Physics 2015-09-02 John W. Barrett

Spectral triples for nonunital algebras model locally compact spaces in noncommutative geometry. In the present text, we prove the local index formula for spectral triples over nonunital algebras, without the assumption of local units in…

Operator Algebras · Mathematics 2013-01-21 A. Carey , V. Gayral , A. Rennie , F. Sukochev

Let X be a compact connected Riemann surface. Fix a positive integer r and two nonnegative integers d_p and d_z. Consider all pairs of the form (F, f), where F is a holomorphic vector bundle on X of rank r and degree d_z-d_p, and f :…

Algebraic Geometry · Mathematics 2014-10-07 Indranil Biswas , Ajneet Dhillon , Jacques Hurtubise , Richard Wentworth

The spectral localizer is a predictive framework for the computation of topological invariants of natural and artificial materials. Here, three crucial improvements on the criterion for the validity of the framework are reported: first,…

Mathematical Physics · Physics 2025-06-18 Alexander Cerjan , Hermann Schulz-Baldes

In the setting of several commuting operators on a Hilbert space one defines the notions of invertibility and Fredholmness in terms of the associated Koszul complex. The index problem then consists of computing the Euler characteristic of…

K-Theory and Homology · Mathematics 2012-10-24 Jens Kaad , Ryszard Nest

We consider the algebra of mixed multidimensional integral operators. In particular, Fredholm integral operators of the first and second kind belongs to this algebra. For the piecewise constant kernels we provide an explicit representation…

Functional Analysis · Mathematics 2017-06-20 Anton A. Kutsenko

We construct spherical harmonics for fuzzy spheres of even and odd dimensions, generalizing the correspondence between finite matrix algebras and fuzzy two-spheres. The finite matrix algebras associated with the various fuzzy spheres have a…

High Energy Physics - Theory · Physics 2014-11-18 Sanjaye Ramgoolam

In noncommutative geometry one is interested in invariants such as the Fredholm index or spectral flow and their calculation using cyclic cocycles. A variety of formulae have been established under side conditions called summability…

Operator Algebras · Mathematics 2009-12-16 Denis Potapov , Fyodor Sukochev

We discuss spectral properties of the equatorial Podles sphere. As a preparation we also study the `degenerate' (i.e. $q=0$) case (related to the quantum disk). We consider two different spectral triples: one related to the Fock…

Quantum Algebra · Mathematics 2009-11-11 Francesco D'Andrea , Ludwik Dabrowski

In this paper, a spectral theorem is proved for self-adjoint cyclically compact partial integral operators in the space of functions with mixed norm, which is a Kaplansky--Hilbert module. The decomposition through eigenfunctions, integral…

Functional Analysis · Mathematics 2025-12-09 K. Kudaybergenov , A. Arziev , P. Orinbaev

We construct, for every even dimensional sphere $S^n$, $n >1$, and every odd integer $k$, a homogeneous polynomial map $f: S^{n}\to S^{n}$ of Brouwer degree $k$ and algebraic degree $2|k|-1$.

Algebraic Topology · Mathematics 2007-05-23 Javier Turiel

This paper discusses the spectral collocation method for numerically solving nonlocal problems: one dimensional space fractional advection-diffusion equation; and two dimensional linear/nonlinear space fractional advection-diffusion…

Numerical Analysis · Mathematics 2014-01-30 WenYi Tian , Weihua Deng , Yujiang Wu

Just as a symmetric surface with separating fixed locus halves into two oriented bordered surfaces, an arbitrary symmetric surface halves into two oriented symmetric half-surfaces, i.e. surfaces with crosscaps. Motivated in part by the…

Symplectic Geometry · Mathematics 2014-07-16 Penka Georgieva , Aleksey Zinger

A C*algebra A generated by a class of zero-order classical pseudodifferential operator on a cylinder RxB, where B is a compact riemannian manifold, containing operators with periodic symbols, is considered. A description of the K-theory…

Differential Geometry · Mathematics 2019-05-07 Severino T. Melo

We produce a variety of odd bounded Fredholm modules and odd spectral triples on Cuntz-Krieger algebras by means of realizing these algebras as "the algebra of functions on a non-commutative space" coming from a sub shift of finite type. We…

K-Theory and Homology · Mathematics 2015-03-02 Magnus Goffeng , Bram Mesland

Let $M$ be a $n$-dimensional complex manifold and $f,g:M\to M$ two distinct holomorphic self-maps. Suppose that $f$ and $g$ coincide on a globally irreducible compact hypersurface $S\subset M$. We show that if one of the two maps is a local…

Complex Variables · Mathematics 2016-04-11 Paolo Arcangeli

Spectral Mackey functors are homotopy-coherent versions of ordinary Mackey functors as defined by Dress. We show that they can be described as excisive functors on a suitable infinity-category, and we use this to show that universal…

Algebraic Topology · Mathematics 2014-06-03 C. Barwick

This paper concerns Fredholm theory in several variables, and its applications to Hilbert spaces of analytic functions. One feature is the introduction of ideas from commutative algebra to operator theory. Specifically, we introduce a…

Functional Analysis · Mathematics 2007-05-23 Xiang Fang

In this paper we begin a study of the space of unbounded self-adjoint Fredholm operators as a classifying space for K^{1}(X), with the goal of incorporating the information in the eigenspaces and eigenvalues of the operators. In particular,…

K-Theory and Homology · Mathematics 2008-05-31 Ronald G. Douglas , Jerome Kaminker