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Related papers: Calder\'on Preconditioners for the TD-EFIE discret…

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We present a boundary integral equation solver for computing Taylor relaxed states in non-axisymmetric solid and shell-like toroidal geometries. The computation of Taylor states in these geometries is a key element for the calculation of…

Numerical Analysis · Mathematics 2019-09-04 Dhairya Malhotra , Antoine Cerfon , Lise-Marie Imbert-Gérard , Michael O'Neil

In this paper we focus on high order finite element approximations of the electric field combined with suitable preconditioners, to solve the time-harmonic Maxwell's equations in waveguide configurations.The implementation of high order…

Numerical Analysis · Mathematics 2020-03-23 Marcella Bonazzoli , Victorita Dolean , Frédéric Hecht , Francesca Rapetti

The domain integral equation method with its FFT-based matrix-vector products is a viable alternative to local methods in free-space scattering problems. However, it often suffers from the extremely slow convergence of iterative methods,…

Numerical Analysis · Mathematics 2015-03-19 Grigorios P. Zouros , Neil V. Budko

When numerical solution of elliptic and parabolic partial differential equations is required to be highly accurate in space, the discrete problem usually takes the form of large-scale and sparse linear systems. In this work, as an…

Numerical Analysis · Mathematics 2024-07-23 Massimo Frittelli , Ivonne Sgura

The accuracy of the electric field integral equation (EFIE) can be substantially improved using high-order discretizations. However, this equation suffers from ill-conditioning and deleterious numerical effects in the low-frequency regime,…

Numerical Analysis · Mathematics 2023-08-30 Johann Bourhis , Adrien Merlini , Francesco P. Andriulli

This paper explores preconditioning the normal equation for non-symmetric square linear systems arising from PDE discretization, focusing on methods like CGNE and LSQR. The concept of ``normal'' preconditioning is introduced and a strategy…

Numerical Analysis · Mathematics 2025-03-03 Lorenzo Lazzarino , Yuji Nakatsukasa , Umberto Zerbinati

Simulating electromagnetic fields across broad frequency ranges is challenging due to numerical instabilities at low frequencies. This work extends a stabilized two-step formulation of Maxwell's equations to the time-domain. Using a…

Numerical Analysis · Mathematics 2025-10-17 Leon Herles , Mario Mally , Jörg Ostrowski , Sebastian Schöps , Melina Merkel

Solving optimization problems with transient PDE-constraints is computationally costly due to the number of nonlinear iterations and the cost of solving large-scale KKT matrices. These matrices scale with the size of the spatial…

Numerical Analysis · Mathematics 2023-05-09 Eric C. Cyr

We introduce a general differentiable solver for time-dependent deformation problems with contact and friction. Our approach uses a finite element discretization with a high-order time integrator coupled with the recently proposed…

We consider a family of conforming space-time discretizations for the wave equation based on a first-order-in-time formulation employing maximal regularity splines. In contrast with second-order-in-time formulations, which require a CFL…

Numerical Analysis · Mathematics 2024-11-04 Matteo Ferrari , Sara Fraschini , Gabriele Loli , Ilaria Perugia

Time-harmonic solutions to the wave equation can be computed in the frequency or in the time domain. In the frequency domain, one solves a discretized Helmholtz equation, while in the time domain, the periodic solutions to a discretized…

Numerical Analysis · Mathematics 2021-10-26 Christiaan C. Stolk

We consider a space-time variational formulation of the second-order wave equation, where integration by parts is also applied with respect to the time variable. Conforming tensor-product finite element discretisations with piecewise…

Numerical Analysis · Mathematics 2021-02-16 Marco Zank

Using the framework of operator or Calder\'on preconditioning, uniform preconditioners are constructed for elliptic operators discretized with continuous finite (or boundary) elements. The preconditioners are constructed as the composition…

Numerical Analysis · Mathematics 2021-10-27 Rob Stevenson , Raymond van Venetië

Large-scale applications of energy density functional (EDF) methods depend on fast and reliable algorithms to solve the associated non-linear self-consistency problem. When dealing with large single-particle variational spaces, existing…

Nuclear Theory · Physics 2019-06-24 W. Ryssens , M. Bender , P. -H. Heenen

We propose the first $\alpha$-parameterized framework for solving time-changed stochastic differential equations (TCSDEs), explicitly linking convergence rates to the driving parameter of the underlying stochastic processes. Theoretically,…

Probability · Mathematics 2025-11-04 Jingwei Chen , Jun Ye , Jinwen Chen , Zhidong Wang

We show some improved mapping properties of the Time Domain Electric Field Integral Equation and of its Galerkin semidiscretization in space. We relate the weak distributional framework with a stronger class of solutions using a group of…

Numerical Analysis · Mathematics 2015-09-04 Tianyu Qiu , Francisco-Javier Sayas

Simulations of laser-induced electron dynamics in a molecular system are performed using time-dependent (TD) equation-of-motion (EOM) coupled-cluster (CC) theory. The target system has been chosen to highlight potential shortcomings of…

Chemical Physics · Physics 2023-08-09 Stephen H. Yuwono , Brandon C. Cooper , Tianyuan Zhang , Xiaosong Li , A. Eugene DePrince

Maxwell equations describe the propagation of electromagnetic waves and are therefore fundamental to understanding many problems encountered in the study of antennas and electromagnetics. The aim of this paper is to propose and analyse an…

Numerical Analysis · Mathematics 2022-10-13 Bin Wang , Yaolin Jiang

We present a simple discretization scheme for the hypersingular integral representation of the fractional Laplace operator and solver for the corresponding fractional Laplacian problem. Through singularity subtraction, we obtain a…

Numerical Analysis · Mathematics 2020-01-29 Victor Minden , Lexing Ying

We consider second-order evolution equations in an abstract setting with damping and time delay and give sufficient conditions ensuring exponential stability. Our abstract framework is then applied to the wave equation, the elasticity…

Analysis of PDEs · Mathematics 2013-08-26 Serge Nicaise , Cristina Pignotti