18.2k citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- ETH ZurichCH101 papers
- Istituto Ricerche Solari LocarnoCH41 papers
- Dalle Molle Institute for Artificial Intelligence ResearchCH39 papers
- Politecnico di MilanoIT30 papers
- Italian Institute of TechnologyIT23 papers
- Institut für SonnenphysikDE22 papers
- University of Applied Sciences and Arts of Southern SwitzerlandCH21 papers
- École Polytechnique Fédérale de LausanneCH19 papers
- University of ExeterGB16 papers
- Austrian Academy of SciencesAT14 papers
- Centre National de la Recherche ScientifiqueFR14 papers
- Tel Aviv UniversityIL14 papers
34 papers · 1 filter
A Preconditioned Version of a Nested Primal-Dual Algorithm for Image Deblurring
Stefano Aleotti, Marco Donatelli, Rolf Krause +1
Variational models for image deblurring problems typically consist of a smooth term and a potentially non-smooth convex term. A common approach to solving these problems is using p…
Two-level trust-region method with random subspaces
Andrea Angino, Alena Kopaničáková, Rolf Krause
We introduce a two-level trust-region method (TLTR) for solving unconstrained nonlinear optimization problems. Our method uses a composite iteration step, which is based on two dis…
Enhancing training of physics-informed neural networks using domain-decomposition based preconditioning strategies
Alena Kopaničáková, Hardik Kothari, George Em Karniadakis +1
We propose to enhance the training of physics-informed neural networks (PINNs). To this aim, we introduce nonlinear additive and multiplicative preconditioning strategies for the w…
Boundary Integral Formulation of the Cell-by-Cell Model of Cardiac Electrophysiology
Giacomo Rosilho de Souza, Rolf Krause, Simone Pezzuto
We propose a boundary element method for the accurate solution of the cell-by-cell bidomain model of electrophysiology. The cell-by-cell model, also called Extracellular-Membrane-I…
Nonlinear Schwarz preconditioning for Quasi-Newton methods
Hardik Kothari
We propose the nonlinear restricted additive Schwarz (RAS) preconditioning strategy to improve the convergence speed of limited memory quasi-Newton (QN) methods. We consider both "…
Level-based Blocking for Sparse Matrices: Sparse Matrix-Power-Vector Multiplication
Christie L. Alappat, Georg Hager, Olaf Schenk +1
The multiplication of a sparse matrix with a dense vector (SpMV) is a key component in many numerical schemes and its performance is known to be severely limited by main memory acc…
Nonlinear Field-split Preconditioners for Solving Monolithic Phase-field Models of Brittle Fracture
Alena Kopaničáková, Hardik Kothari, Rolf Krause
One of the state-of-the-art strategies for predicting crack propagation, nucleation, and interaction is the phase-field approach. Despite its reliability and robustness, the phase-…
Numerical solutions to linear transfer problems of polarized radiation II. Krylov methods and matrix-free implementation
Pietro Benedusi, Gioele Janett, Luca Belluzzi +1
Context. Numerical solutions to transfer problems of polarized radiation in solar and stellar atmospheres commonly rely on stationary iterative methods, which often perform poorly…
A Generalized Multigrid Method for Solving Contact Problems in Lagrange Multiplier based Unfitted Finite Element Method
Hardik Kothari, Rolf Krause
Internal interfaces in a domain could exist as a material defect or they can appear due to propagations of cracks. Discretization of such geometries and solution of the contact pro…
High-order interpolatory Serendipity Virtual Element Method for semilinear parabolic problems
Sergio Gómez
We propose an efficient method for the numerical approximation of a general class of two dimensional semilinear parabolic problems on polygonal meshes. The proposed approach takes…
A Multigrid Preconditioner for Jacobian-free Newton-Krylov Methods
Hardik Kothari, Alena Kopaničáková, Rolf Krause
In this work, we propose a multigrid preconditioner for Jacobian-free Newton-Krylov (JFNK) methods. Our multigrid method does not require knowledge of the Jacobian at any level of…
Multigrid and saddle-point preconditioners for unfitted finite element modelling of inclusions
Hardik Kothari, Rolf Krause
In this work, we consider the modeling of inclusions in the material using an unfitted finite element method. In the unfitted methods, structured background meshes are used and onl…
A novel equi-dimensional finite element method for flow and transport in fractured porous media satisfying discrete maximum principle and conservation properties
Maria Giuseppina Chiara Nestola, Marco Favino
Numerical simulations of flow and transport in porous media usually rely on hybrid-dimensional models, i.e., the fracture is considered as objects of a lower dimension compared to…
A fast direct solver for nonlocal operators in wavelet coordinates
Helmut Harbrecht, Michael Multerer
In this article, we consider fast direct solvers for nonlocal operators. The pivotal idea is to combine a wavelet representation of the system matrix, yielding a quasi-sparse matri…
Verification benchmarks for single-phase flow in three-dimensional fractured porous media
Inga Berre, Wietse M. Boon, Bernd Flemisch +23
Flow in fractured porous media occurs in the earth's subsurface, in biological tissues, and in man-made materials. Fractures have a dominating influence on flow processes, and the…
High Performance Block Incomplete LU Factorization
Matthias Bollhöfer, Olaf Schenk, Fabio Verbosio
Many application problems that lead to solving linear systems make use of preconditioned Krylov subspace solvers to compute their solution. Among the most popular preconditioning a…
Recursive multilevel trust region method with application to fully monolithic phase-field models of brittle fracture
Alena Kopaničáková, Rolf Krause
The simulation of crack initiation and propagation in an elastic material is difficult, as crack paths with complex topologies have to be resolved. Phase-field approach allows to s…
Nonisometric Surface Registration via Conformal Laplace-Beltrami Basis Pursuit
Stefan C. Schonsheck, Michael M. Bronstein, Rongjie Lai
Surface registration is one of the most fundamental problems in geometry processing. Many approaches have been developed to tackle this problem in cases where the surfaces are near…
High-dimensional and higher-order multifidelity Monte Carlo estimators
Alessio Quaglino, Simone Pezzuto, Rolf Krause
Multifidelity Monte Carlo methods rely on a hierarchy of possibly less accurate but statistically correlated simplified or reduced models, in order to accelerate the estimation of…
Rapid computation of far-field statistics for random obstacle scattering
Helmut Harbrecht, Nikola Ilić, Michael D. Multerer
In this article, we consider the numerical approximation of far-field statistics for acoustic scattering problems in the case of random obstacles. In particular, we consider the co…
A note on the domain mapping method with rough diffusion coefficients
M. D. Multerer
In this article, we consider elliptic diffusion problems on random domains with non-smooth diffusion coefficients. We start by illustrating the problems that arise from a non-smoot…
An Iterative Approach for Time Integration Based on Discontinuous Galerkin Methods
Xiaozhou Li, Pietro Benedusi, Rolf Krause
We present a new class of iterative schemes for solving initial value problems (IVP) based on discontinuous Galerkin (DG) methods. Starting from the weak DG formulation of an IVP,…
Multiscale modeling, discretization, and algorithms: a survey in biomechanics
Marco Favino, Alessio Quaglino, Sonia Pozzi +2
Multiscale models allow for the treatment of complex phenomena involving different scales, such as remodeling and growth of tissues, muscular activation, and cardiac electrophysiol…
A high-order Boris integrator
Mathias Winkel, Robert Speck, Daniel Ruprecht
This work introduces the high-order Boris-SDC method for integrating the equations of motion for electrically charged particles in an electric and magnetic field. Boris-SDC relies…