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Related papers: The Microscopic Dirac Operator Spectrum

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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

We summarize our recent investigations of lattice QCD with dynamical overlap fermions. We sketch algorithmic issues and our approach to solving them. We show our measurement of the topological susceptibility. We describe a computation of…

High Energy Physics - Lattice · Physics 2007-05-23 Stefan Schaefer , Thomas DeGrand

We apply a complex chiral random matrix model as an effective model to QCD with a small chemical potential at zero temperature. In our model the correlation functions of complex eigenvalues can be determined analytically in two different…

High Energy Physics - Lattice · Physics 2017-08-23 G. Akemann , T. Wettig

We adapt the well-known spectral decimation technique for computing spectra of Laplacians on certain symmetric self-similar sets to the case of magnetic Schrodinger operators and work through this method completely for the diamond lattice…

Classical Analysis and ODEs · Mathematics 2020-04-24 Antoni Brzoska , Aubrey Coffey , Madeline Rooney , Stephen Loew , Luke G. Rogers

We report on our progress in using the overlap-Dirac fermion operator in simulations of lattice QCD. We have investigated the Lanczos based method of Borici, as well as various rational approximations, to calculate the step function in the…

High Energy Physics - Lattice · Physics 2011-04-15 UKQCD Collaboration , Craig McNeile

We present a numerical study of the properties of the Fixed Point lattice Dirac operator in the Schwinger model. We verify the theoretical bounds on the spectrum, the existence of exact zero modes with definite chirality, and the Index…

High Energy Physics - Lattice · Physics 2009-10-31 Federico Farchioni , Victor Laliena

We prove quadratic estimates for complex perturbations of Dirac-type operators, and thereby show that such operators have a bounded functional calculus. As an application we show that spectral projections of the Hodge--Dirac operator on…

Spectral Theory · Mathematics 2009-11-10 Andreas Axelsson , Stephen Keith , Alan McIntosh

We solve a new chiral Random Two-Matrix Theory by means of biorthogonal polynomials for any matrix size $N$. By deriving the relevant kernels we find explicit formulas for all $(n,k)$-point spectral (mixed or unmixed) correlation functions.…

High Energy Physics - Theory · Physics 2008-11-26 G. Akemann , P. H. Damgaard , J. C. Osborn , K. Splittorff

We consider orthogonal connections with arbitrary torsion on compact Riemannian manifolds. For the induced Dirac operators, twisted Dirac operators and Dirac operators of Chamseddine-Connes type we compute the spectral action. In addition…

Mathematical Physics · Physics 2015-06-04 Frank Pfaeffle , Christoph A. Stephan

We propose new techniques for the numerical implementation of the overlap-Dirac operator, which exploit the physical properties of the underlying theory to avoid nested algorithms. We test these procedures in the two-dimensional Schwinger…

High Energy Physics - Lattice · Physics 2009-11-07 Leonardo Giusti , Christian Hoelbling , Claudio Rebbi

We only require generalized chiral symmetry and $\gamma_5$-hermiticity, which leads to a large class of Dirac operators describing massless fermions on the lattice, and use this framework to give an overview of developments in this field.…

High Energy Physics - Lattice · Physics 2009-11-07 Werner Kerler

Random Matrix Theory has been a unifying approach in physics and mathematics.In these lectures we discuss applications of Random Matrix Theory to QCD and emphasize underlying integrable structures. In the first lecture we give an overview…

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

In lattice QCD it is possible, in principle, to determine the parameters in the effective chiral lagrangian (including weak interaction couplings) by performing numerical simulations in the $\epsilon$--regime, i.e. at quark masses where the…

High Energy Physics - Lattice · Physics 2011-07-19 L. Giusti , C. Hoelbling , M. Lüscher , H. Wittig

We investigate the spectral properties of a random matrix model, which in the large $N$ limit, embodies the essentials of the QCD partition function at low energy. The exact spectral density and its pair correlation function are derived for…

High Energy Physics - Theory · Physics 2011-04-20 Jacobus Verbaarschot

We have computed ensembles of complete spectra of the staggered Dirac operator using four-dimensional SU(2) gauge fields, both in the quenched approximation and with dynamical fermions. To identify universal features in the Dirac spectrum,…

High Energy Physics - Lattice · Physics 2009-10-31 M. E. Berbenni-Bitsch , M. Göckeler , S. Meyer , A. Schäfer , T. Wettig

We develop the method of similar operators to study the spectral properties of unbounded perturbed linear operators that can be represented by matrices of various kinds. The class of operators under consideration includes various…

Functional Analysis · Mathematics 2019-08-13 Anatoly G. Baskakov , Ilya A. Krishtal , Natalia B. Uskova

Two numerical algorithms for the computation of eigenvalues of Dirac operators in lattice gauge theories are described: one is an accelerated conjugate gradient method, the other one a standard Lanczos method. Results obtained by Cullum's…

High Energy Physics - Lattice · Physics 2009-10-28 Thomas Kalkreuter

Recent results on the spectral properties of the Hermitian Wilson-Dirac operator are presented.

High Energy Physics - Lattice · Physics 2009-10-31 Rajamani Narayanan

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 paper we show how to construct a Dirac operator on a lattice in complete analogy with the continuum. In fact we consider a more general problem, that is, the Dirac operator over an abelian finite group (for which a lattice is a…

High Energy Physics - Theory · Physics 2012-08-27 Jayme Vaz,