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The spectral propinquity is a distance, up to unitary equivalence, on the class of metric spectral triples. We prove in this paper that if a sequence of metric spectral triples converges for the propinquity, then the spectra of the Dirac…

Operator Algebras · Mathematics 2024-07-15 Frederic Latremoliere

We study random perturbations of quasi-periodic uniformly discrete sets in the $d$-dimensional euclidean space. By means of Diffraction Theory, we find conditions under which a quasi-periodic set $X$ can be almost surely recovered from its…

Probability · Mathematics 2022-12-29 Mircea Petrache , Rodolfo Viera

Examples of noncommutative self-coverings are described, and spectral triples on the base space are extended to spectral triples on the inductive family of coverings, in such a way that the covering projections are locally isometric. Such…

Operator Algebras · Mathematics 2016-12-21 Valeriano Aiello , Daniele Guido , Tommaso Isola

In this paper we construct odd finitely summable spectral triples based on length functions of bounded doubling on noncommutative solenoids. Our spectral triples induce a Leibniz Lip-norm on the state spaces of the noncommutative solenoids,…

Operator Algebras · Mathematics 2022-12-16 Carla Farsi , Therese Basa Landry , Nadia S. Larsen , Judith A. Packer

In this second part of the paper, we define spectral spacetimes, a noncommutative generalization of Lorentzian orientable spacetimes of even dimension with a spin structure. There are two main differences with spectral triples: the…

Operator Algebras · Mathematics 2016-11-24 Fabien Besnard

We introduce the notion of a pre-spectral triple, which is a generalisation of a spectral triple $(\mathcal{A}, H, D)$ where $D$ is no longer required to be self-adjoint, but closed and symmetric. Despite having weaker assumptions,…

Operator Algebras · Mathematics 2019-01-08 Alain Connes , Galina Levitina , Edward McDonald , Fedor Sukochev , Dmitriy Zanin

For a unital C*-algebra A, which is equipped with a spectral triple and an extension T of A by the compacts, we construct a family of spectral triples associated to T and depending on the two positive parameters (s,t). Using Rieffel's…

Operator Algebras · Mathematics 2009-11-13 Erik Christensen , Cristina Ivan

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 show that the first five of the axioms we had formulated on spectral triples suffice (in a slightly stronger form) to characterize the spectral triples associated to smooth compact manifolds. The algebra, which is assumed to be…

Operator Algebras · Mathematics 2008-10-14 Alain Connes

We study spectral properties of second order elliptic operators with periodic coefficients in dimension two. These operators act in periodic simply-connected waveguides, with either Dirichlet, or Neumann, or the third boundary condition.…

Spectral Theory · Mathematics 2007-05-23 E. Shargorodsky , A. V. Sobolev

We complete the classification of almost commutative geometries from a particle physics point of view given in hep-th/0312276. Four missing Krajewski diagrams will be presented after a short introduction into irreducible, non-degenerate…

High Energy Physics - Theory · Physics 2009-11-11 Jan-H. Jureit , Christoph A. Stephan

This proceeding presents a synthesis of recent results on the emergence of pseudo-Riemannian structures from twisted spectral triples within the almostcommutative framework. It provides a unified algebraic mechanism for addressing the…

Mathematical Physics · Physics 2026-05-12 Gaston Nieuviarts

We consider stability and approximate reconstruction of Riemannian manifold when the finite number of eigenvalues of the Laplace-Beltrami operator and the boundary values of the corresponding eigenfunctions are given. The reconstruction can…

Analysis of PDEs · Mathematics 2007-05-23 Atsushi Katsuda , Yaroslav Kurylev , Matti Lassas

This article is about erroneous attempts to weaken the standard definition of unbounded Kasparov module (or spectral triple). We present counterexamples to claims in the literature that Fredholm modules can be obtained from these weaker…

K-Theory and Homology · Mathematics 2019-11-28 I. Forsyth , B. Mesland , A. Rennie

We study a class of rooted trees with a substitution type structure. These trees are not necessarily regular, but exhibit a lot of symmetries. We consider nearest neighbor operators which reflect the symmetries of the trees. The spectrum of…

Spectral Theory · Mathematics 2015-03-17 Matthias Keller

In this work we demonstrate how different semi-classical methods can be combined in a novel way to reconstruct the perturbation potential of ultra compact stars. Besides rather general assumptions, the only specific information entering…

General Relativity and Quantum Cosmology · Physics 2017-08-09 Sebastian H. Völkel , Kostas D. Kokkotas

We study the Connes spectral distance of quantum states and analyse the nonlocality of a 4D generalized noncommutative phase space. By virtue of the Hilbert-Schmidt operatorial formulation, we obtain the Dirac operator and construct a…

Mathematical Physics · Physics 2025-09-09 Bing-Sheng Lin , Tai-Hua Heng

We study the quasimap invariants of elliptic and K3 fibrations. Oberdieck and Pixton conjectured that the Gromov-Witten potentials of elliptic fibrations are quasi-modular forms. Analogously, we propose similar conjecture for the quasimap…

Algebraic Geometry · Mathematics 2019-04-24 Hyenho Lho

In this paper, we prove fibration theorems for manifolds with almost nonnegative Ricci curvature and certain extra regularity assumptions. We show that a closed $n$-manifold $M$ satisfying $\mathrm{diam}(M)^2\mathrm{sec}_M \geq -\kappa$ and…

Differential Geometry · Mathematics 2026-05-26 Hongzhi Huang , Xian-Tao Huang , Jikang Wang , Xingyu Zhu

We construct a canonical geometrically realised Connes spectral triple or `Dirac operator' $D\!\!\!/$ from the data of a quantum metric $g\in \Omega^1\otimes_A\Omega^1$ and quantum Levi-Civita bimodule connection, at the pre-Hilbert space…

Quantum Algebra · Mathematics 2023-05-16 Shahn Majid