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In this paper, we give the definitions of the non-self-adjoint spectral triple and its spectral Einstein functional. We compute the spectral Einstein functional associated with the nonminimal de Rham-Hodge operator on even-dimensional…

Differential Geometry · Mathematics 2025-02-11 Hongfeng Li , Yong Wang

The spectral metric and Einstein functionals defined by two vector fields and Laplace-type operators over vector bundles, giving an interesting example of the spinor connection and square of the Dirac operator. Motivated by the spectral…

Differential Geometry · Mathematics 2025-06-09 Jian Wang , Yong Wang

We find and classify possible equivariant spin structures with Dirac operators on the noncommutative torus, proving that similarly as in the classical case the spectrum of the Dirac operator depends on the spin structure.

Quantum Algebra · Mathematics 2018-06-04 Mario Paschke , Andrzej Sitarz

It is well-known that a compact Riemannian spin manifold can be reconstructed from its canonical spectral triple which consists of the algebra of smooth functions, the Hilbert space of square integrable spinors and the Dirac operator. It…

Differential Geometry · Mathematics 2011-11-09 Christian Baer

We extend several classical eigenvalue estimates for Dirac operators on compact manifolds to noncompact, even incomplete manifolds. This includes Friedrich's estimate for manifolds with positive scalar curvature as well as the author's…

Differential Geometry · Mathematics 2009-07-16 Christian Baer

In the paper, given two vector fields and the Witten deformation, we compute the spectral Einstein functional for the Witten deformation on even-dimensional spin manifolds without boundary.

Differential Geometry · Mathematics 2026-02-06 Tong Wu , Yong Wang

We consider an elliptic self-adjoint first order pseudodifferential operator acting on columns of m complex-valued half-densities over a connected compact n-dimensional manifold without boundary. The eigenvalues of the principal symbol are…

Analysis of PDEs · Mathematics 2012-05-01 Olga Chervova , Robert J. Downes , Dmitri Vassiliev

We show that the algebra A of a commutative unital spectral triple (A,H,D) satisfying several additional conditions, slightly stronger than those proposed by Connes, is the algebra of smooth functions on a compact spin manifold.

Operator Algebras · Mathematics 2008-02-04 Adam Rennie , Joseph C. Varilly

We investigate manifolds with boundary in noncommutative geometry. Spectral triples associated to a symmetric differential operator and a local boundary condition are constructed. For a classical Dirac operator with a chiral boundary…

Mathematical Physics · Physics 2010-09-30 Bruno Iochum , Cyril Levy

We study conformal $Spin$-subgeometry of submanifolds in a semi-Riemannian $Spin$-manifold, focusing on conformal $Spin$-manifolds $(M,[h])$ and their Poincar\'e-Einstein metrics $(X,g_+)$. Our approach is based on the spectral theory of…

Differential Geometry · Mathematics 2014-05-30 Matthias Fischmann , Petr Somberg

We show the existence of nonsymmetric homogeneous spin Riemannian manifolds whose Dirac operator is like that on a Riemannian symmetric spin space. Such manifolds are exactly the homogeneous spin Riemannian manifolds $(M,g)$ which are…

Differential Geometry · Mathematics 2016-02-10 P. M. Gadea , José C. González-Dávila , José A. Oubiña

In [17], we obtained the spectral Einstein functional associated with the Dirac operator for n-dimensional manifolds without boundary. In this paper, we give the proof of general Dabrowski-Sitarz-Zalecki type theorems for the spectral…

Differential Geometry · Mathematics 2023-08-31 Tong Wu , Yong Wang

We define bilinear functionals of vector fields and differential forms, the densities of which yield the metric and Einstein tensors on even-dimensional Riemannian manifolds. We generalise these concepts in non-commutative geometry and, in…

Differential Geometry · Mathematics 2023-06-09 Ludwik Dąbrowski , Andrzej Sitarz , Paweł Zalecki

Using Weitzenb\"ock techniques on any compact Riemannian spin manifold we derive a general inequality depending on a real parameter and joining the spectrum of the Dirac operator with terms depending on the Ricci tensor and its first…

Differential Geometry · Mathematics 2007-05-23 Klaus-Dieter Kirchberg

We present a result for non-compact manifolds with invertible Dirac operator, where we link the presence of a massless Killing spinor, with a harmonic, closed conformal Killing-Yano tensor, if one exists for the specic manifold. A couple of…

High Energy Physics - Theory · Physics 2020-03-16 C. Rugina , A. Ludu

Spectral triples over noncommutative principal $\T^n$-bundles are studied, extending recent results about the noncommutative geometry of principal U(1)-bundles. We relate the noncommutative geometry of the total space of the bundle with the…

Quantum Algebra · Mathematics 2013-08-23 Alessandro Zucca , Ludwik Dabrowski

Considering a four dimensional parallelisable manifold, we develop a concept of Dirac-type tensor equations with wave functions that belong to left ideals of the set of nonhomogeneous complex valued differential forms.

Mathematical Physics · Physics 2019-10-21 Nikolai Marchuk

We consider the self-adjoint operator $H=H_0+V$, where $H_0$ is the free semi-classical Dirac operator on $R^3$. We suppose that the smooth matrix-valued potential $V=O(<x>^{-\delta}), \delta>0,$ has an analytic continuation in a complex…

Spectral Theory · Mathematics 2009-11-11 Abdallah Khochman

We study the spectrum of the Dirac operator $D$ on pseudo-Riemannian spin manifolds of signature $(p,q)$, considered as an unbounded operator in the Hilbert space $L^2_\xi(S)$. The definition of $L^2_\xi(S)$ involves the choice of a…

Differential Geometry · Mathematics 2016-09-14 Momsen Reincke

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