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In lattice QCD computations a substantial amount of work is spent in solving discretized versions of the Dirac equation. Conventional Krylov solvers show critical slowing down for large system sizes and physically interesting parameter…

High Energy Physics - Lattice · Physics 2014-04-29 Andreas Frommer , Karsten Kahl , Stefan Krieg , Björn Leder , Matthias Rottmann

The Szymanzik improvement program for gauge theories is most commonly implemented using forward finite difference corrections to the Wilson action. Central symmetric schemes naively applied, suffer from a doubling of degrees of freedom,…

High Energy Physics - Lattice · Physics 2022-11-22 Alexander Rothkopf

In this work we discuss the deformed relativistic wave equations, namely the Klein--Gordon and Dirac equations in a Doubly Special Relativity scenario. We employ what we call a geometric approach, based on the geometry of a curved momentum…

High Energy Physics - Theory · Physics 2023-02-15 S. A. Franchino-Viñas , J. J. Relancio

Based on integrable Hamiltonian systems related to the derivative Schwarzian Korteweg-de Vries (SKdV) equation, a novel discrete Lax pair for the lattice SKdV (lSKdV) equation is given by two copies of a Darboux transformation which can be…

Exactly Solvable and Integrable Systems · Physics 2020-04-21 Xiaoxue Xu , Cewen Cao , Guangyao Zhang

We develope a difference calculus analogous to the differential geometry by translating the forms and exterior derivatives to similar expressions with difference operators, and apply the results to fields theory on the lattice [Ref. 1]. Our…

High Energy Physics - Lattice · Physics 2007-05-23 M. Lorente

We expand a discrete--time lattice sine--Gordon equation on multiple lattices and obtain the partial difference equation which governs its far field behaviour. Such reduction allow us to obtain a new completely discrete nonlinear…

Mathematical Physics · Physics 2016-09-07 Xiaoda Ji , Decio Levi , Matteo Petrera

Various solutions to the discrete Schwarzian KdV equation are discussed. We first derive the bilinear difference equations of Hirota type of the discrete Schwarzian KP equation, which is decomposed into three discrete two-dimensional Toda…

Exactly Solvable and Integrable Systems · Physics 2015-03-18 Mike Hay , Kenji Kajiwara , Tetsu Masuda

In lattice QCD computations a substantial amount of work is spent in solving linear systems arising in Wilson's discretization of the Dirac equations. We show first numerical results of the extension of the two-level DD-\alpha AMG method to…

High Energy Physics - Lattice · Physics 2013-07-24 A. Frommer , K. Kahl , S. Krieg , B. Leder , M. Rottmann

We derive the Klein--Gordon equation for a single scalar field coupled to gravity at second order in perturbation theory and leading order in slow-roll. This is done in two ways: we derive the Klein--Gordon equation first using the Einstein…

Astrophysics · Physics 2009-06-23 Karim A. Malik , David Seery , Kishore N. Ananda

We establish global existence and derive sharp pointwise decay estimates of solutions to cubic Dirac and Dirac-Klein-Gordon systems on a curved background, close to the Minkowski spacetime. By squaring the Dirac operator, we reduce the…

Analysis of PDEs · Mathematics 2025-08-26 Seokchang Hong

In recent publications, the author and his coworkers have proposed a multigrid method for solving linear systems arizing from the discretization of partial differential equations in isogeometric analysis and have proven that the convergence…

Numerical Analysis · Mathematics 2021-03-05 Stefan Takacs

We study the Dirac equation coupled to scalar and vector Klein-Gordon fields in the limit of strong coupling and large masses of the fields. We prove convergence of the solutions to those of a cubic non-linear Dirac equation, given that the…

Analysis of PDEs · Mathematics 2021-10-19 Jonas Lampart , Loïc Le Treust , Simona Rota Nodari , Julien Sabin

A nonlocal method to obtain discrete classical fields is presented. This technique relies on well-behaved matrix representations of the derivatives constructed on a non--equispaced lattice. The drawbacks of lattice theory like the fermion…

High Energy Physics - Lattice · Physics 2009-10-31 Rafael G. Campos , Eduardo S. Tututi , L. O. Pimentel

We present an adaptive multigrid Dirac solver developed for Wilson clover fermions which offers order-of-magnitude reductions in solution time compared to conventional Krylov solvers. The solver incorporates even-odd preconditioning and…

High Energy Physics - Lattice · Physics 2011-05-25 J. C. Osborn , R. Babich , J. Brannick , R. C. Brower , M. A. Clark , S. D. Cohen , C. Rebbi

The purpose of this paper is to present a class of particular solutions of a C(2,1) conformally invariant nonlinear Klein-Gordon equation by symmetry reduction. Using the subgroups of similitude group reduced ordinary differential equations…

solv-int · Physics 2009-10-31 F. Gungor

It is well known that the block Krylov subspace solvers work efficiently for some cases of the solution of differential equations with multiple right-hand sides. In lattice QCD calculation of physical quantities on a given configuration…

High Energy Physics - Lattice · Physics 2009-12-04 T. Sakurai , H. Tadano , Y. Kuramashi

We review the numerical analysis' understanding of Krylov subspace methods for solving (non-hermitian) systems of equations and discuss its implications for lattice gauge theory computations using the example of the Wilson fermion matrix.…

High Energy Physics - Lattice · Physics 2009-10-28 Andreas Frommer

The spatial discretization of the single-cone Dirac Hamiltonian on the surface of a topological insulator or superconductor needs a special "staggered" grid, to avoid the appearance of a spurious second cone in the Brillouin zone. We adapt…

Mesoscale and Nanoscale Physics · Physics 2021-12-15 M. J. Pacholski , G. Lemut , J. Tworzydło , C. W. J. Beenakker

A finite difference scheme for the numerical treatment of the (3+1)D Dirac equation is presented. Its staggered-grid intertwined discretization treats space and time coordinates on equal footing, thereby avoiding the notorious fermion…

Computational Physics · Physics 2015-06-09 René Hammer , Walter Pötz , Anton Arnold

We continue the program, presented in previous Symposia, of discretizing physical models. In particular we calculate the integral Lorentz transformations with the help of discrete reflection groups, and use them for the covariance of…

High Energy Physics - Lattice · Physics 2007-05-23 M. Lorente