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Related papers: Tricks to implement the overlap Dirac operator

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The overlap formula for the chiral determinant is presented and the realization of gauge anomalies and gauge field toplogy in this context is discussed. The ability of the overlap formalism to deal with supersymmetric theories and…

High Energy Physics - Lattice · Physics 2009-09-25 Rajamani Narayanan

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

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

In this paper we prove that Dirac operators on non-compact complete orbifolds which are sufficiently regular at infinity, admit a unique extension. Additonally, we prove a generalized orbifold Stokes'/Divergence theorem.

Differential Geometry · Mathematics 2008-09-22 Carla Farsi

We present algorithmic improvements to the overlap Hybrid Monte Carlo algorithm, including preconditioning techniques and improvements to the correction step, used when one of the eigenvalues of the Kernel operator changes sign, which is…

High Energy Physics - Lattice · Physics 2007-05-23 N. Cundy , S. Krieg , Th. Lippert

The problem of how to compute accurately and efficiently the sign of the overlap between two general HFB wave functions is addressed. The results obtained can easily be extrapolated to the evaluation of the sign of the trace of a density…

Nuclear Theory · Physics 2009-03-04 Luis M. Robledo

We describe the shape of the symplectic Dirac operators on Hermitian symmetric spaces. For this, we consider these operators as families of operators that can be handled more easily than the original ones.

Symplectic Geometry · Mathematics 2008-04-24 Steffen Brasch , Katharina Habermann , Lutz Habermann

The index bundle of the Overlap lattice Dirac operator over the orbit space of lattice gauge fields is introduced and studied. Obstructions to the vanishing of gauge anomalies in the Overlap formulation of lattice chiral gauge theory have a…

High Energy Physics - Lattice · Physics 2009-11-07 David H. Adams

An overlap representation is an assignment of sets to the vertices of a graph in such a way that two vertices are adjacent if and only if the sets assigned to them overlap. The overlap number of a graph is the minimum number of elements…

Discrete Mathematics · Computer Science 2010-08-17 Bill Rosgen , Lorna Stewart

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 determine the free field hypercubic Dirac operator which is optimally close to satisfying the Ginsparg-Wilson relation. Inserting this operator into the overlap formula, we show that the analytic locality bound on the resulting overlap…

High Energy Physics - Lattice · Physics 2009-11-10 David H. Adams

I show how to avoid a two level nested conjugate gradient procedure in the context of Hybrid Monte Carlo with the overlap fermionic action. The resulting procedure is quite similar to Hybrid Monte Carlo with domain wall fermions, but is…

High Energy Physics - Lattice · Physics 2016-08-25 Herbert Neuberger

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 establish an upper estimate for the small eigenvalues of the twisted Dirac operator on Kahler submanifolds in Kahler manifolds carrying Kahlerian Killing spinors. We then compute the spectrum of the twisted Dirac operator of the…

Differential Geometry · Mathematics 2011-01-26 Nicolas Ginoux , Georges Habib

We evaluate for arbitrary even dimensions the classical continuum limit of the lattice axial anomaly defined by the overlap-Dirac operator. Our calculational scheme is simple and systematic. In particular, a powerful topological argument is…

High Energy Physics - Lattice · Physics 2009-11-07 Takanori Fujiwara , Keiichi Nagao , Hiroshi Suzuki

We show the result of the lattice gauge field tensor which is derived from the classical continuum limit of the overlap Dirac operator. By analogous construction, it was recently proposed that the gauge action can be obtained from the…

High Energy Physics - Lattice · Physics 2009-04-14 K. F. Liu

The chiral Dirac determinant is calculated using the overlap formalism of Narayanan and Neuberger. We compare the real and imaginary parts of the determinant with the continuum result for perturbative gauge field backgrounds and show that…

High Energy Physics - Lattice · Physics 2008-02-03 Per Ernstrom , Ansar Fayyazuddin

In the paper, we give four different examples of the rescaled Dirac operator by the perturbation of the function f. Further, based on the trilinear Clifford multiplication by functional of differential one-forms, we compute the spectral…

Differential Geometry · Mathematics 2025-06-09 Tong Wu , Yong Wang

We examine spectra of Dirac operators on compact hyperbolic surfaces. Particular attention is devoted to symmetry considerations, leading to non-trivial multiplicities of eigenvalues. The relation to spectra of Maass-Laplace operators is…

Mathematical Physics · Physics 2007-05-23 Jens Bolte , Hans-Michael Stiepan

We define a sparse hermitian lattice Dirac matrix, $H$, coupling $2n+1$ Dirac fermions. When $2n$ fermions are integrated out the induced action for the last fermion is a rational approximation to the hermitian overlap Dirac operator. We…

High Energy Physics - Lattice · Physics 2009-10-31 R. Narayanan , H. Neuberger

Odd-dimensional Riemannian spaces that are non-orientable, but have a pin structure, require the consideration of the twisted adjoint representation of the corresponding pin group. It is shown here how the Dirac operator should be modified,…

High Energy Physics - Theory · Physics 2011-04-15 Andrzej Trautman