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A new numerical method to calculate exact ground states of multi-fluxline systems with quenched disorder is presented, which is based on the minimum cost flow algorithm from combinatorial optimization. We discuss several models that can be…

Superconductivity · Physics 2009-10-31 H. Rieger

Acoustic wave propagation through a homogeneous material embedded in an unbounded medium can be formulated as a boundary integral equation and accurately solved with the boundary element method. The computational efficiency deteriorates at…

Numerical Analysis · Mathematics 2024-02-21 Elwin van 't Wout

In magnetic confinement fusion devices, the equilibrium configuration of a plasma is determined by the balance between the hydrostatic pressure in the fluid and the magnetic forces generated by an array of external coils and the plasma…

Numerical Analysis · Mathematics 2021-11-24 Howard C. Elman , Jiaxing Liang , Tonatiuh Sánchez-Vizuet

We present a time-dependent framework that combines a hybrid Gaussian-FEDVR basis with a multicenter grid to simulate strong-field and attosecond dynamics in atoms and molecules. The method incorporates the construction of the orthonormal…

Atomic Physics · Physics 2025-11-17 Kyle A. Hamer , Heman Gharibnejad , Luca Argenti , Nicolas Douguet

Extrapolations of solar photospheric vector magnetograms into three-dimensional magnetic fields in the chromosphere and corona are usually done under the assumption that the fields are force-free. The field calculations can be improved by…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Fuhrmann , N. Seehafer , G. Valori , T. Wiegelmann

In electromagnetic simulations of magnets and machines one is often interested in a highly accurate and local evaluation of the magnetic field uniformity. Based on local post-processing of the solution, a defect correction scheme is…

Numerical Analysis · Mathematics 2017-02-09 Ulrich Römer , Sebastian Schöps , Herbert De Gersem

We develop an accurate square-root-free algorithm for constructing real Givens rotations. On processors that support the fused multiply-add operation in hardware, the algorithm is competitive with square-root based algorithms using a…

Numerical Analysis · Mathematics 2025-08-28 Carlos F. Borges

An improved particle swarm optimization algorithm is proposed and its superiority over standard particle swarm optimization algorithm is tested on two typical benchmark functions. By employing this algorithm to search for the magnetic…

Strongly Correlated Electrons · Physics 2024-03-14 Ze Ruan , Xiu-Cai Jiang , Ze-Yi Song , Yu-Zhong Zhang

A robust multilevel preconditioner based on the hybridizable discontinuous Galerkin method for the Helmholtz equation with high wave number is presented in this paper. There are two keys in our algorithm, one is how to choose a suitable…

Numerical Analysis · Mathematics 2014-03-05 Huangxin Chen , Peipei Lu , Xuejun Xu

We develop an algorithm that combines model-based and model-free methods for solving a nonlinear optimal control problem with a quadratic cost in which the system model is given by a linear state-space model with a small additive nonlinear…

Optimization and Control · Mathematics 2022-03-23 Yansong Li , Shuo Han

We introduce a hybrid high-order method for approximating the ground state of the nonlinear Gross--Pitaevskii eigenvalue problem. Optimal convergence rates are proved for the ground state approximation, as well as for the associated…

Numerical Analysis · Mathematics 2025-06-26 Moritz Hauck , Yizhou Liang

We present an algorithmic study for the simulation of two massless flavors of O(a) improved Wilson quarks with Schroedinger functional boundary conditions. The algorithm used is Hybrid Monte Carlo with two pseudo-fermion fields as proposed…

High Energy Physics - Lattice · Physics 2009-11-10 F. Knechtli , M. Della Morte , J. Rolf , R. Sommer , I. Wetzorke , U. Wolff

Works of D. Tsiklauri, T. Haruki, Phys. of Plasmas, 15, 102902 (2008) and D. Tsiklauri and T. Haruki, Phys. of Plasmas, 14, 112905, (2007) are extended by inclusion of the out-of-plane magnetic (guide) field. In particular, magnetic…

Solar and Stellar Astrophysics · Physics 2014-02-12 J. Graf von der Pahlen , D. Tsiklauri

We present an improved upper bound for the ground state energy of lattice fermion models with sign problem. The bound can be computed by numerical simulation of a recently proposed family of deformed Hamiltonians with no sign problem. For…

High Energy Physics - Lattice · Physics 2009-11-07 Matteo Beccaria

Based on a second-order approximation of nonlinear force-free magnetic field solutions in terms of uniformly twisted field lines derived in Paper I, we develop here a numeric code that is capable to forward-fit such analytical solutions to…

Solar and Stellar Astrophysics · Physics 2015-06-05 Markus J. Aschwanden , Anna Malanushenko

We primarily study a special a weighted low-rank approximation of matrices and then apply it to solve the background modeling problem. We propose two algorithms for this purpose: one operates in the batch mode on the entire data and the…

Computer Vision and Pattern Recognition · Computer Science 2018-04-18 Aritra Dutta , Xin Li , Peter Richtarik

We compare the statistics of driven, supersonic turbulence at high Mach number using FLASH a widely used Eulerian grid-based code and PHANTOM, a Lagrangian SPH code at resolutions of up to 512^3 in both grid cells and SPH particles. We find…

Astrophysics of Galaxies · Physics 2015-05-18 Daniel J. Price , Christoph Federrath

The popularity of local meshless methods in the field of numerical simulations has increased greatly in recent years. This is mainly due to the fact that they can operate on scattered nodes and that they allow a direct control over the…

Numerical Analysis · Mathematics 2022-06-29 Mitja Jančič , Gregor Kosec

Magnetostatic field calculations in micromagnetic simulations can be numerically expensive, particularly in the case of large-scale finite element simulations. The established finite element / boundary element method (FEM/BEM) by Fredkin &…

Numerical Analysis · Mathematics 2019-03-27 Riccardo Hertel , Sven Christophersen , Steffen Börm

This article concerns the weak Galerkin mixed finite element method (WG-MFEM) for second order elliptic equations on 2D domains with curved boundary. The Neumann boundary condition is considered since it becomes the essential boundary…

Numerical Analysis · Mathematics 2022-11-09 Yi Liu , Wenbin Chen , Yanqiu Wang