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We define the notion of a twisted topological graph algebra associated to a topological graph and a $1$-cocycle on its edge set. We prove a stronger version of a Vasselli's result. We expand Katsura's results to study twisted topological…

Operator Algebras · Mathematics 2019-02-20 Hui Li

Gromov proved a quadratic decay inequality of scalar curvature for a class of complete manifolds. In this paper, we prove that for any uniformly contractible manifold with finite asymptotic dimension, its scalar curvature decays to zero at…

Differential Geometry · Mathematics 2021-06-22 Jinmin Wang , Zhizhang Xie , Guoliang Yu

For each K-homolgy element of the Sierpinski gasket we construct a spectral triple which will generate that element. We show that there must be certain limits on the choice of the K-homology element if the geometric properties of the gasket…

Operator Algebras · Mathematics 2011-09-22 Erik Christensen , Cristina Ivan , Elmar Schrohe

The computation of the matrix exponential is a ubiquitous operation in numerical mathematics, and for a general, unstructured $n\times n$ matrix it can be computed in $\mathcal{O}(n^3)$ operations. An interesting problem arises if the input…

Numerical Analysis · Mathematics 2021-06-02 Daniel Kressner , Robert Luce

Using the Levi-Civita connection on the noncommutative differential one-forms of a spectral triple $(\B,\H,\D)$, we define the full Riemann curvature tensor, the Ricci curvature tensor and scalar curvature. We give a definition of Dirac…

Operator Algebras · Mathematics 2024-06-28 Bram Mesland , Adam Rennie

In the paper the general case of a normal discrete Hausdorff operators in $L^2(\mathbb{R}^d)$ is considered. The main result states that under some natural arithmetic condition the spectrum of such an operator is rotationally invariant.…

Functional Analysis · Mathematics 2023-07-12 A. R. Mirotin

Considering pure transmission scattering problems in piecewise constant media, we derive an exact analytic formula for the spectrum of the corresponding local multi-trace boundary integral operators in the case where the geometrical…

Analysis of PDEs · Mathematics 2015-08-04 Xavier Claeys

We study countable sums of two dimensional modules for the continuous complex functions on a compact metric space and show that it is possible to construct a spectral triple which gives the original metric back. This spectral triple will be…

Operator Algebras · Mathematics 2007-05-23 Erik Christensen , Cristina Ivan

We propose a general procedure to construct noncommutative deformations of an embedded submanifold $M$ of $\mathbb{R}^n$ determined by a set of smooth equations $f^a(x)=0$. We use the framework of Drinfel'd twist deformation of differential…

Mathematical Physics · Physics 2021-06-30 Gaetano Fiore , Thomas Weber

This paper leverages the use of \emph{Gram iteration} an efficient, deterministic, and differentiable method for computing spectral norm with an upper bound guarantee. Designed for circular convolutional layers, we generalize the use of the…

Machine Learning · Computer Science 2024-02-02 Blaise Delattre , Quentin Barthélemy , Alexandre Allauzen

We establish generic uniform convergence guarantees for Gaussian data in terms of the Rademacher complexity of the hypothesis class and the Lipschitz constant of the square root of the scalar loss function. We show how these guarantees…

Machine Learning · Statistics 2023-06-26 Lijia Zhou , Zhen Dai , Frederic Koehler , Nathan Srebro

This article gives a simple treatment of the quantum Birkhoff normal form for semiclassical pseudo-differential operators with smooth coefficients. The normal form is applied to describe the discrete spectrum in a generalised non-degenerate…

Spectral Theory · Mathematics 2009-02-11 Laurent Charles , San Vu Ngoc

Algorithms for numerical computation of symmetric elliptic integrals of all three kinds are improved in several ways and extended to complex values of the variables (with some restrictions in the case of the integral of the third kind).…

Classical Analysis and ODEs · Mathematics 2015-06-26 Bille C. Carlson

A proper etale Lie groupoid is modelled as a (noncommutative) spectral geometric space. The spectral triple is built on the algebra of smooth functions on the groupoid base which are invariant under the groupoid action. Stiefel-Whitney…

Mathematical Physics · Physics 2014-12-16 Antti J. Harju

In this paper we present a complete spectral analysis of Dirac operators with non-Hermitian matrix potentials of the form $i\operatorname{sgn}(x)+V(x)$ where $V\in L^1$. For $V=0$ we compute explicitly the matrix Green function. This allows…

Spectral Theory · Mathematics 2025-04-09 Lyonell Boulton , David Krejcirik , Tho Nguyen Duc

This paper is to study what we call twisted regular representations for vertex operator algebras. Let $V$ be a vertex operator algebra, let $\sigma_1,\sigma_2$ be commuting finite-order automorphisms of $V$ and let…

Quantum Algebra · Mathematics 2022-06-08 Haisheng Li , Jiancai Sun

Let $M$ be a closed smooth connected spin manifold of even dimension $n$, let $g$ be a Riemannian metric of regularity $W^{1,p}$, $p > n$, on $M$ whose distributional scalar curvature in the sense of Lee-LeFloch is bounded below by…

Differential Geometry · Mathematics 2023-12-15 Simone Cecchini , Bernhard Hanke , Thomas Schick

We construct a local Lipschitz graph around a soliton of the cubic focusing NLS in three dimensions on which global solutions exist, and asymptotic stability as well as scattering holds.

Analysis of PDEs · Mathematics 2007-05-23 Wilhelm Schlag

A recognized trend of research investigates generalizations of the Hadamard's inversion theorem to functions that may fail to be differentiable. In this vein, the present paper explores some consequences of a recent result about the…

Optimization and Control · Mathematics 2023-09-22 Amos Uderzo

By twisting a given link $L$ along an unknotted circle $c$, we obtain an infinite family of links $\{ L_n \}$. We introduce the ``stable unknotting number'' which describes the asymptotic behavior of unknotting numbers of links in the twist…

Geometric Topology · Mathematics 2025-04-08 Kenneth L. Baker , Yasuyuki Miyazawa , Kimihiko Motegi