54 citations · 396 across the 28 of their papers we have counts for
30 papers
Neutral band gap of carbon by quantum Monte Carlo methods
V. Gorelov, Y. Yang, M. Ruggeri +3
We present a method of calculating the energy gap of a charge-neutral excitation using only ground-state calculations. We report Quantum Monte Carlo calculations of …
Goal-oriented adaptivity for multilevel stochastic Galerkin FEM with nonlinear goal functionals
Alex Bespalov, Dirk Praetorius, Michele Ruggeri
This paper is concerned with the numerical approximation of quantities of interest associated with solutions to parametric elliptic partial differential equations (PDEs). The key n…
The mass-lumped midpoint scheme for computational micromagnetics: Newton linearization and application to magnetic skyrmion dynamics
Giovanni Di Fratta, Carl-Martin Pfeiler, Dirk Praetorius +1
We discuss a mass-lumped midpoint scheme for the numerical approximation of the Landau-Lifshitz-Gilbert equation, which models the dynamics of the magnetization in ferromagnetic ma…
Multi-scale simulation of the adsorption of lithium ion on graphite surface: from Quantum Monte Carlo to Molecular Density Functional Theory
Michele Ruggeri, Kyle Reeves, Tzu-Yao Hsu +3
The structure of the double-layer formed at the surface of carbon electrodes is governed by the interactions between the electrode and the electrolyte species. However, carbon is n…
Rational-approximation-based model order reduction of Helmholtz frequency response problems with adaptive finite element snapshots
Francesca Bonizzoni, Davide Pradovera, Michele Ruggeri
We introduce several spatially adaptive model order reduction approaches tailored to non-coercive elliptic boundary value problems, specifically, parametric-in-frequency Helmholtz…
Unconditional well-posedness and IMEX improvement of a family of predictor-corrector methods in micromagnetics
Norbert J. Mauser, Carl-Martin Pfeiler, Dirk Praetorius +1
Recently, Kim & Wilkening (Convergence of a mass-lumped finite element method for the Landau-Lifshitz equation, Quart. Appl. Math., 76, 383-405, 2018) proposed two novel predictor-…
Gamma-convergent projection-free finite element methods for nematic liquid crystals: The Ericksen model
Ricardo H. Nochetto, Michele Ruggeri, Shuo Yang
The Ericksen model for nematic liquid crystals couples a director field with a scalar degree of orientation variable, and allows the formation of various defects with finite energy…
Numerical analysis of the Landau-Lifshitz-Gilbert equation with inertial effects
Michele Ruggeri
We consider the numerical approximation of the inertial Landau-Lifshitz-Gilbert equation (iLLG), which describes the dynamics of the magnetization in ferromagnetic materials at sub…
Micromagnetics of thin films in the presence of Dzyaloshinskii-Moriya interaction
Elisa Davoli, Giovanni Di Fratta, Dirk Praetorius +1
In this paper, we study the thin-film limit of the micromagnetic energy functional in the presence of bulk Dzyaloshinskii-Moriya interaction (DMI). Our analysis includes both a sta…
Quantum Monte Carlo determination of the principal Hugoniot of deuterium
Michele Ruggeri, Markus Holzmann, David M. Ceperley +1
We present Coupled Electron-Ion Monte Carlo results for the principal Hugoniot of deuterium together with an accurate study of the initial reference state of shock wave experiments…
Two-level a posteriori error estimation for adaptive multilevel stochastic Galerkin FEM
Alex Bespalov, Dirk Praetorius, Michele Ruggeri
The paper considers a class of parametric elliptic partial differential equations (PDEs), where the coefficients and the right-hand side function depend on infinitely many (uncerta…
A time splitting method for the three-dimensional linear Pauli equation
Timon S. Gutleb, Norbert J. Mauser, Michele Ruggeri +1
We analyze a numerical method to solve the time-dependent linear Pauli equation in three space dimensions. The Pauli equation is a semi-relativistic generalization of the Schröding…
The saturation assumption yields optimal convergence of two-level adaptive BEM
Dirk Praetorius, Michele Ruggeri, Ernst P. Stephan
We consider the convergence of adaptive BEM for weakly-singular and hypersingular integral equations associated with the Laplacian and the Helmholtz operator in 2D and 3D. The loca…
Computational micromagnetics with Commics
Carl-Martin Pfeiler, Michele Ruggeri, Bernhard Stiftner +6
We present our open-source Python module Commics for the study of the magnetization dynamics in ferromagnetic materials via micromagnetic simulations. It implements state-of-the-ar…
Convergence of adaptive stochastic Galerkin FEM
Alex Bespalov, Dirk Praetorius, Leonardo Rocchi +1
We propose and analyze novel adaptive algorithms for the numerical solution of elliptic partial differential equations with parametric uncertainty. Four different marking strategie…
Iterative solution and preconditioning for the tangent plane scheme in computational micromagnetics
Johannes Kraus, Carl-Martin Pfeiler, Dirk Praetorius +2
The tangent plane scheme is a time-marching scheme for the numerical solution of the nonlinear parabolic Landau-Lifshitz-Gilbert equation (LLG), which describes the time evolution…
Goal-oriented error estimation and adaptivity for elliptic PDEs with parametric or uncertain inputs
Alex Bespalov, Dirk Praetorius, Leonardo Rocchi +1
We use the ideas of goal-oriented error estimation and adaptivity to design and implement an efficient adaptive algorithm for approximating linear quantities of interest derived fr…
Correlation energies of the high-density spin-polarized electron gas to meV accuracy
Michele Ruggeri, Pablo López Ríos, Ali Alavi
We present a novel combination of quantum Monte Carlo methods and a finite size extrapolation framework with which we calculate the thermodynamic limit of the exact correlation ene…
Convergent tangent plane integrators for the simulation of chiral magnetic skyrmion dynamics
Gino Hrkac, Carl-Martin Pfeiler, Dirk Praetorius +3
We consider the numerical approximation of the Landau-Lifshitz-Gilbert equation, which describes the dynamics of the magnetization in ferromagnetic materials. In addition to the cl…
Linear second-order IMEX-type integrator for the (eddy current) Landau-Lifshitz-Gilbert equation
Giovanni Di Fratta, Carl-Martin Pfeiler, Dirk Praetorius +2
Combining ideas from [Alouges et al. (Numer. Math., 128, 2014)] and [Praetorius et al. (Comput. Math. Appl., 2017)], we propose a numerical algorithm for the integration of the non…
Nonlinear Network description for many-body quantum systems in continuous space
Michele Ruggeri, Saverio Moroni, Markus Holzmann
We show that the recently introduced iterative backflow renormalization can be interpreted as a general neural network in continuum space with non-linear functions in the hidden un…
Convergence of an implicit-explicit midpoint scheme for computational micromagnetics
Dirk Praetorius, Michele Ruggeri, Bernhard Stiftner
Based on lowest-order finite elements in space, we consider the numerical integration of the Landau-Lifschitz-Gilbert equation (LLG). The dynamics of LLG is driven by the so-called…
A self-consistent spin-diffusion model for micromagnetics
Claas Abert, Michele Ruggeri, Florian Bruckner +4
We propose a three-dimensional micromagnetic model that dynamically solves the Landau-Lifshitz-Gilbert equation coupled to the full spin-diffusion equation. In contrast to previous…
Low-density phases of He monolayers adsorbed on graphite
Michele Ruggeri, Ettore Vitali, Davide Emilio Galli +2
Quantum Monte Carlo simulations at zero temperature of a He monolayer adsorbed on graphite, either clean or preplated with He, unexpectedly point to a gas-liquid phase tran…