English
Related papers

Related papers: Tricks to implement the overlap Dirac operator

200 papers

We discuss the steps to construct Dirac operators which have arbitrary fermion offsets, gauge paths, a general structure in Dirac space and satisfy the basic symmetries (gauge symmetry, hermiticity condition, charge conjugation, hypercubic…

High Energy Physics - Lattice · Physics 2009-10-31 P. Hasenfratz , S. Hauswirth , K. Holland , T. Jorg , F. Niedermayer , U. Wenger

We investigate a number of algorithms that calculate the quark propagators for the overlap-Dirac fermion operator. The QCD simulations were performed at beta = 5.9 with a lattice volume of 16**3*32.

High Energy Physics - Lattice · Physics 2015-06-25 UKQCD Collaboration , Craig McNeile , Alan Irving , Chris Michael

Operator fields in the bundle of Dirac spinors and their conversion to spatial fields are considered. Some commutator equations are studied with the use of the conversion technique.

Differential Geometry · Mathematics 2008-02-12 Ruslan Sharipov

In this article, we present the symmetry group of a global slice Dirac operator and its iterated ones. Further, the explicit forms of intertwining operators of the iterated global slice Dirac operator are given. At the end, we introduce a…

Complex Variables · Mathematics 2024-09-17 Chao Ding , Zhenghua Xu

Dirac operators and Dirac cohomology for Lie superalgebras of Riemannian type, introduced by Huang and Pand\v{z}i\'{c}, provide an effective tool for the study of unitarizable supermodules. In this article, we study these objects for Lie…

Representation Theory · Mathematics 2026-03-24 Steffen Schmidt

New exact upper and lower bounds are derived on the spectrum of the square of the hermitian Wilson Dirac operator. It is hoped that the derivations and the results will be of help in the search for ways to reduce the cost of simulations…

High Energy Physics - Lattice · Physics 2009-07-09 H. Neuberger

In this note, we prove lower and upper bounds for Dirac operators of submanifolds in certain ambient manifolds in terms of conformal and extrinsic quantities.

Differential Geometry · Mathematics 2018-10-18 Qun Chen , Linlin Sun

We discuss the adaptation of the Hybrid Monte Carlo algorithm to overlap fermions. We derive a method which can be used to account for the delta function in the fermionic force caused by the differential of the sign function. We discuss the…

High Energy Physics - Lattice · Physics 2009-11-11 Nigel Cundy

We present first results of a mixed action project. We analyze gauge configurations generated with two flavors of dynamical twisted mass fermions. Neuberger's overlap Dirac operator is used for the valence sector. The various choices in the…

High Energy Physics - Lattice · Physics 2008-11-26 O. Bar , K. Jansen , S. Schaefer , L. Scorzato , A. Shindler

In this largely expository paper we give a self-contained treatment of the Dirac operator. Emphasizing the algebraic point of view we first sketch the necessary prerequisites from Clifford algebras and their representations and then define…

Differential Geometry · Mathematics 2007-05-23 Herbert Schroeder

We construct an $O(a^2)$-improved overlap-Dirac operator by designing an improved overlap kernel, based on the Symanzik improvement program. Field rotation terms are also identified to improve off-shell amplitudes for both massless and…

High Energy Physics - Lattice · Physics 2010-11-05 H. Ikeda , S. Hashimoto

We define the notion of a co-Riemannian structure and show how it can be used to define the Dirac operator on an appropriate infinite dimensional manifold. In particular, this approach works for the smooth loop space of a so-called string…

Differential Geometry · Mathematics 2008-09-19 Andrew Stacey

We present a method for the numerical calculation of derivatives of functions of general complex matrices. The method can be used in combination with any algorithm that evaluates or approximates the desired matrix function, in particular…

High Energy Physics - Lattice · Physics 2016-10-13 M. Puhr , P. V. Buividovich

The extreme computational costs of calculating the sign of the Wilson matrix within the overlap operator have so far prevented four dimensional dynamical overlap simulations on realistic lattice sizes, because the computational power…

High Energy Physics - Lattice · Physics 2008-12-18 N. Cundy , S. Krieg , G. Arnold , A. Frommer , Th. Lippert , K. Schilling

We construct a universal spin$_c$ Dirac operator on $\mathbb{C}P^n$ built by projecting $su(n+1)$ left actions and prove its equivalence to the standard right action Dirac operator on $\mathbb{C}P^n$. The eigenvalue problem is solved and…

High Energy Physics - Theory · Physics 2016-10-10 Idrish Huet , Julieta Medina

We consider supersymmetric quantum mechanical systems in arbitrary dimensions on curved spaces with nontrivial gauge fields. The square of the Dirac operator serves as Hamiltonian. We derive a relation between the number of supercharges…

High Energy Physics - Theory · Physics 2009-11-10 A. Kirchberg , J. D. Laenge , A. Wipf

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 integer valued topological index of a Dirac operator is introduced for a pair of a 4n+2 dimensional open Spin^c manifold and a section of the determinant line bundle satisfying some property. We show a relation between the index and an…

Differential Geometry · Mathematics 2014-01-22 Shin Hayashi

We present an improved version of the cyclic covering trick, which works inside the category of toroidal embeddings

Algebraic Geometry · Mathematics 2015-10-12 Florin Ambro

We construct new Ginsparg-Wilson fermions for QCD by inserting an approximately chiral Dirac operator - which involves ingredients of a perfect action - into the overlap formula. This accelerates the convergence of the overlap Dirac…

High Energy Physics - Lattice · Physics 2010-04-05 W. Bietenholz