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Related papers: Limit-Periodic Dirac Operators with Thin Spectra

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We compute the spectral density of the (Hermitean) Dirac operator in Quantum Chromodynamics with two light degenerate quarks near the origin. We use CLS/ALPHA lattices generated with two flavours of O(a)-improved Wilson fermions…

High Energy Physics - Lattice · Physics 2015-03-25 Georg P. Engel , Leonardo Giusti , Stefano Lottini , Rainer Sommer

We study the spectrum of the QCD Dirac operator near zero virtuality for $N_c =2$. According to a universality argument, it can be described by a random matrix theory with the chiral structure of QCD, but with $real$ matrix elements. Using…

High Energy Physics - Theory · Physics 2009-10-28 Jacobus Verbaarschot

A generalized two-dimensional periodic Dirac operator is considered, with $L^{\infty}$-matrix-valued coefficients of the first order derivatives and with complex matrix-valued potential. It is proved that if the matrix-valued potential has…

Mathematical Physics · Physics 2007-05-23 L. I. Danilov

We show that tensoring the Laplace and Dolbeault-Dirac operators of a K\"ahler structure (with closed integral) by a negative Hermitian holomorphic module, produces operators with spectral gaps around zero. The proof is based on the…

Quantum Algebra · Mathematics 2022-06-27 Biswarup Das , Réamonn Ó Buachalla , Petr Somberg

For non-critical almost Mathieu operators with Diophantine frequency, we establish exponential asymptotics on the size of spectral gaps, and show that the spectrum is homogeneous. We also prove the homogeneity of the spectrum for…

Dynamical Systems · Mathematics 2017-12-14 Martin Leguil , Jiangong You , Zhiyan Zhao , Qi Zhou

The spectra of massless Dirac operators are of essential interest e.g. for the electronic properties of graphene, but fundamental questions such as the existence of spectral gaps remain open. We show that the eigenvalues of massless Dirac…

Spectral Theory · Mathematics 2015-09-29 Karl Michael Schmidt , Tomio Umeda

In this work, we develop the method of multipliers for electromagnetic Dirac operators and establish sufficient conditions on the magnetic and electric fields that guarantee the absence of point spectrum. In the massless case, our approach…

Spectral Theory · Mathematics 2025-12-17 Naiara Arrizabalaga , Lucrezia Cossetti , Matias Morales

We consider Sch\"odinger operators on the half-line, both discrete and continuous, and show that the absence of bound states implies the absence of embedded singular spectrum. More precisely, in the discrete case we prove that if $\Delta +…

Mathematical Physics · Physics 2014-12-30 David Damanik , Rowan Killip

We construct examples of one-dimensional Schr\"odinger operators that illustrate the subtle nature of fractal continuity properties of spectral measures. First, we present half-line operators whose spectral measures have packing dimension…

Spectral Theory · Mathematics 2025-05-13 Netanel Levi

We investigate spectral properties of limit-periodic Schr\"odinger operators in $\ell^2(\Z)$. Our goal is to exhibit as rich a spectral picture as possible. We regard limit-periodic potentials as generated by continuous sampling along the…

Spectral Theory · Mathematics 2012-05-31 Zheng Gan

We prove that the massless Dirac operator in $\mathbb{R^3}$ with long-range potential has an a.c. spectrum which fills the whole real line. The Dirac operators with matrix-valued potentials are considered as well.

Mathematical Physics · Physics 2007-05-23 S. A. Denisov

In this paper we extend the traditional framework of noncommutative geometry in order to deal with spectral truncations of geometric spaces (i.e. imposing an ultraviolet cutoff in momentum space) and with tolerance relations which provide a…

Quantum Algebra · Mathematics 2020-08-26 Alain Connes , Walter D. van Suijlekom

Almost commutative models provide a framework for Connes' work on the standard model of particle physics. These models are constructed as products of a the canonical spectral triple of a compact connected spin manifold with a finite…

Operator Algebras · Mathematics 2026-03-20 Frederic Latremoliere

Let $\gH$ be a Hilbert space and let $A$ be a simple symmetric operator in $\gH$ with equal deficiency indices $d:=n_\pm(A)<\infty$. We show that if, for all $\l$ in an open interval $I\subset\bR$, the dimension of defect subspaces…

Functional Analysis · Mathematics 2010-12-20 Vadim Mogilevskii

In this paper, we prove that for any $d$-frequency analytic quasiperiodic Schr\"odinger operator, if the frequency is weak Liouvillean, and the potential is small enough, then the corresponding operator has absolutely continuous spectrum.…

Dynamical Systems · Mathematics 2020-04-10 Xuanji Hou , Jing Wang , Qi Zhou

We consider the wave equation with a distributional Dirac damping and Dirichlet boundary conditions on a compact interval. It is shown that the spectrum of the corresponding wave operator is fully determined by zeroes of an entire function.…

Spectral Theory · Mathematics 2025-10-14 Mikuláš Kučera

We investigate the spectrum of the Dirac operator with infinite mass boundary conditions posed in a tubular neighborhood of a smooth compact hypersurface in $\mathbb{R}^n$ without boundary. We prove that when the tubular neighborhood…

Spectral Theory · Mathematics 2023-07-19 Vladimir Lotoreichik , Thomas Ourmières-Bonafos

We consider an elliptic self-adjoint first order differential operator acting on pairs (2-columns) of complex-valued half-densities over a connected compact 3-dimensional manifold without boundary. The principal symbol of our operator is…

Spectral Theory · Mathematics 2015-05-05 Olga Chervova , Robert J. Downes , Dmitri Vassiliev

We prove $-\Delta +V$ has purely discrete spectrum if $V\geq 0$ and, for all $M$, $|\{x\mid V(x)<M\}|<\infty$ and various extensions.

Spectral Theory · Mathematics 2008-10-21 Barry Simon

We consider the two-dimensional Dirac operator with infinite mass boundary conditions posed in a tubular neighborhood of a $C^4$-planar curve. Under generic assumptions on its curvature $\kappa$, we prove that in the thin-width regime the…

Spectral Theory · Mathematics 2022-07-19 William Borrelli , Nour Kerraoui , Thomas Ourmières-Bonafos