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Related papers: Solving the Grad-Shafranov equation using spectral…

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We present an arbitrary-order spectral element method for general-purpose simulation of non-overturning water waves, described by fully nonlinear potential theory. The method can be viewed as a high-order extension of the classical finite…

Computational Physics · Physics 2016-06-22 Allan Peter Engsig-Karup , Claes Eskilsson , Daniele Bigoni

We propose a new method for solving the Gelfand-Levitan-Marchenko equation (GLME) based on the block version of the Toeplitz Inner-Bordering (TIB) with an arbitrary point to start the calculation. This makes it possible to find solutions of…

Numerical Analysis · Mathematics 2021-11-25 Sergey Medvedev , Irina Vaseva , Mikhail Fedoruk

In this paper, we advocate a novel spline-based isogeometric approach for boundary elements and its efficient implementation. We compare solutions obtained by both an isogeometric approach, and a classical parametric higher-order approach…

Computational Engineering, Finance, and Science · Computer Science 2018-07-11 Jürgen Dölz , Stefan Kurz , Sebastian Schöps , Felix Wolf

The Kitaev model is a remarkable spin model with gapped and gapless spin liquid phases, which are potentially realized in iridates and $\alpha$-RuCl$_3$. In the recent experiment of $\alpha$-RuCl$_3$, the signature of a nematic transition…

Strongly Correlated Electrons · Physics 2021-07-21 Masahiko G. Yamada , Satoshi Fujimoto

The study of the electrodynamics of static, axisymmetric and force-free Kerr magnetospheres relies vastly on solutions of the so called relativistic Grad-Shafranov equation (GSE). Different numerical approaches to the solution of the GSE…

High Energy Astrophysical Phenomena · Physics 2018-05-08 J. F. Mahlmann , P. Cerdá-Durán , M. A. Aloy

In this paper, we investigate a spectral Petrov-Galerkin method for fractional initial value problems. Singularities of the solution at the origin inherited from the weakly singular kernel of the fractional derivative are considered, and…

Numerical Analysis · Mathematics 2021-09-07 Shengyue Li , Wanrong Cao , Zhaopeng Hao

In this work we will treat the spurious eigenvalues obstacle that appears in the computation of the radial Dirac eigenvalue problem using numerical methods. The treatment of the spurious solution is based on applying Petrov-Galerkin finite…

Numerical Analysis · Mathematics 2017-09-14 Hasan Almanasreh

We present a new tunably-accurate Laguerre Petrov-Galerkin spectral method for solving linear multi-term fractional initial value problems with derivative orders at most one and constant coefficients on the half line. Our method results in…

Numerical Analysis · Mathematics 2016-07-29 Anna Lischke , Mohsen Zayernouri , George Em Karniadakis

We study a space-time finite element approach for the nonhomogeneous wave equation using a continuous time Galerkin method. We present fully implicit examples in 1+1, 2+1, and 3+1 dimensions using linear quadrilateral, hexahedral, and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Matthew Anderson , Jung-Han Kimn

In this paper we consider the spectral and nonlinear stability of periodic traveling wave solutions of a generalized Kuramoto-Sivashinsky equation. In particular, we resolve the long-standing question of nonlinear modulational stability by…

Analysis of PDEs · Mathematics 2015-06-04 Blake Barker , Mathew A. Johnson , Pascal Noble , L. Miguel Rodrigues , Kevin Zumbrun

In this paper we present a methodology for increasing the accuracy and accelerating the convergence of numerical methods for solution of Maxwell's equations in the frequency domain by taking into account the be-havior of the electromagnetic…

Computational Physics · Physics 2021-06-30 Igor Semenikhin

3D free boundary equilibrium computations have recently been used to model external kinks and edge harmonic oscillations (EHOs), comparing with linear MHD stability codes, and nonlinear analytic theory [Kleiner et al, PPCF 61 084005…

A formulation is developed for general relativistic ideal magnetohydrodynamics in stationary axisymmetric spacetimes. We reduce basic equations to a single second-order partial differential equation, the so-called Grad-Shafranov (GS)…

General Relativity and Quantum Cosmology · Physics 2009-10-09 Kunihito Ioka , Misao Sasaki

We present a scalable 2D Galerkin spectral element method solution to the linearized potential flow radiation problem for wave induced forcing of a floating offshore structure. The pseudo-impulsive formulation of the problem is solved in…

Numerical Analysis · Mathematics 2023-02-22 Jens Visbech , Allan P. Engsig-Karup , Harry B. Bingham

We derive exact solutions of a linear form of the Grad-Shafranov (GS) equation, including incompressible equilibrium flow, using ansatz-based similarity reduction methods. The linearity of the equilibrium equation allows linear combinations…

Plasma Physics · Physics 2016-08-31 Dimitrios A. Kaltsas , George N. Throumoulopoulos

The ALLIANCE code is developed to solve a new set of four-dimensional electromagnetic drift-kinetic equations in slab geometry [J. Plasma Phys. 88 905880117 (2022)]. The nonlinear equations are useful for the study of magnetized plasma…

Plasma Physics · Physics 2024-10-07 Evgeny A. Gorbunov , Bogdan Teaca

In this paper, we introduce a novel analytical solution to Tolman-Oppenheimer-Volkoff (TOV) equation, which is ultimately a hydrostatic equilibrium equation derived from the general relativity in the framework of relativistic isothermal…

General Relativity and Quantum Cosmology · Physics 2017-05-01 A. S. Saad , M. I. Nouh , A. A. Shaker , T. M. Kamel

A new modified Galerkin / Finite Element Method is proposed for the numerical solution of the fully nonlinear shallow water wave equations. The new numerical method allows the use of low-order Lagrange finite element spaces, despite the…

Numerical Analysis · Mathematics 2016-09-21 Dimitrios Mitsotakis , Costas Synolakis , Mark Mcguinness

We propose two efficient energetic spectral-element methods in time for marching nonlinear gradient systems with the phase-field Allen--Cahn equation as an example: one fully implicit nonlinear method and one semi-implicit linear method.…

Numerical Analysis · Mathematics 2026-05-06 Shiqin Liu , Haijun Yu

Weak gravitational, electromagnetic, neutrino and scalar fields, considered as perturbations on Kerr background satisfy Teukolsky Master Equation. The two non-trivial equations obtained after separating the variables are the polar angle…

General Relativity and Quantum Cosmology · Physics 2014-10-14 Roumen S. Borissov , Plamen P. Fiziev