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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

In this talk we review some recent results from random matrix models as applied to some non-perturbative issues in QCD. All of the issues we will discuss touched upon the important phenomenon related to the spontaneous breaking of chiral…

High Energy Physics - Phenomenology · Physics 2007-05-23 Romuald A. Janik , Maciej A. Nowak , Gabor Papp , Ismail Zahed

We compare the lower edge spectral fluctuations of the staggered lattice Dirac operator for the Schwinger model with the predictions of chiral Random Matrix Theory (chRMT). We verify their range of applicability, checking in particular the…

High Energy Physics - Lattice · Physics 2009-10-31 F. Farchioni , I. Hip , C. B. Lang

We carry the index theory for manifolds with boundary of B\"ar and Ballmann over to first order differential operators on metric graphs. This approach results in a short proof for the index of such operators. Then the self-adjoint…

Spectral Theory · Mathematics 2024-03-20 Alberto Richtsfeld

The overlap formula proposed by Narayanan and Neuberger in chiral gauge theories is examined. The free chiral and Dirac Green's functions are constructed in this formalism. Four dimensional anomalies are calculated and the usual anomaly…

High Energy Physics - Theory · Physics 2009-10-28 S. Randjbar-Daemi , J. Strathdee

We compute the microscopic spectrum of the QCD Dirac operator in the presence of dynamical fermions in the framework of random-matrix theory for the chiral Gaussian unitary ensemble. We obtain results for the microscopic spectral…

High Energy Physics - Theory · Physics 2009-10-30 T. Wilke , T. Guhr , T. Wettig

We investigate the eigenvalues and eigenvectors of the staggered Dirac operator in the vicinity of the chiral phase transition of quenched SU(3) lattice gauge theory. We consider both the global features of the spectrum and the local…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , H. Hehl , P. E. L. Rakow , A. Schäfer , W. Söldner , T. Wettig

This is a survey article on a known generalization of Dirac-type operators to transverse operators called basic Dirac operators on Riemannian foliations, which are smooth foliations that have a transverse geometric structure. Construction…

Differential Geometry · Mathematics 2009-09-01 Ken Richardson

The aim of this paper is to study the existence of eigenvalues in the gap of the essential spectrum of the one-dimensional Dirac operator in the presence of a bounded potential. We employ a generalized variational principle to prove…

Spectral Theory · Mathematics 2025-03-24 Daniel Sánchez-Mendoza , Monika Winklmeier

The action of the overlap-Dirac operator on a vector is typically implemented in directly through a multi-shift conjugate gradient solver. The compute-time this takes to evaluate depends upon the condition number $\kappa$ of the matrix that…

High Energy Physics - Lattice · Physics 2010-03-04 W. Kamleh , D. Adams , D. B. Leinweber , A. G. Williams

This paper is devoted to a general min-max characterization of the eigenvalues in a gap of the essential spectrum of a self-adjoint unbounded operator. We prove an abstract theorem, then we apply it to the case of Dirac operators with a…

Spectral Theory · Mathematics 2022-06-14 Jean Dolbeault , Maria J. Esteban , Eric Séré

The overlap operator is just the simplest of a class of Dirac operators with an exact chiral symmetry. I demonstrate how a general class of chiral Dirac operators can be constructed, show that they have no fermion doublers and that they are…

High Energy Physics - Lattice · Physics 2008-11-26 Nigel Cundy

The zero momentum sectors in effective theories of QCD coupled to pseudoreal (two colors) and real (adjoint) quarks have alternative descriptions in terms of chiral orthogonal and symplectic ensembles of random matrices. Using this…

High Energy Physics - Theory · Physics 2009-10-31 T. Nagao , S. M. Nishigaki

With the Schwinger model as example I discuss properties of lattice Dirac operators, with some emphasis on Monte Carlo results for topological charge, chiral fermions and eigenvalue spectra.

High Energy Physics - Lattice · Physics 2007-05-23 C. B. Lang

According to the Banks-Casher formula the chiral order parameter is directly related to the spectrum of the Dirac operator. In this lecture, we will argue that some properties of the Dirac spectrum are universal and can be obtained from a…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. J. M. Verbaarschot

In this article, we study the spectrum of the magnetic Dirac operator, and the magnetic Dirac operator with potential over complete Riemannian manifolds. We find sufficient conditions on the potentials as well as the manifold so that the…

Spectral Theory · Mathematics 2023-12-25 Nelia Charalambous , Nadine Große

An explicit, detailed evaluation of the classical continuum limit of the axial anomaly/index density of the overlap Dirac operator is carried out in the infinite volume setting, and in a certain finite volume setting where the continuum…

High Energy Physics - Lattice · Physics 2009-10-31 David H. Adams

We derive a number of spectral results for Dirac operators in geometrically nontrivial regions in $\mathbb{R}^2$ and $\mathbb{R}^3$ of tube or layer shapes with a zigzag type boundary using the corresponding properties of the Dirichlet…

Spectral Theory · Mathematics 2022-10-26 Pavel Exner , Markus Holzmann

We present a formulation of chiral gauge theories, which admits more general spectra of Dirac operators and reveals considerably more possibilities for the structure of the chiral projections. Our two forms of correlation functions both…

High Energy Physics - Lattice · Physics 2009-11-10 Werner Kerler

We argue that the spectrum of the QCD Dirac operator near zero virtuality can be described by random matrix theory. As in the case of classical random matrix ensembles of Dyson we have three distinct classes: the chiral orthogonal ensemble…

High Energy Physics - Theory · Physics 2011-07-18 Jacobus Verbaarschot