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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

A wide variety of (fixed-point) iterative methods for the solution of nonlinear equations (in Hilbert spaces) exists. In many cases, such schemes can be interpreted as iterative local linearization methods, which, as will be shown, can be…

Numerical Analysis · Mathematics 2019-10-16 Pascal Heid , Thomas P. Wihler

We devise a space-time tensor method for the low-rank approximation of linear parabolic evolution equations. The proposed method is a stable Galerkin method, uniformly in the discretization parameters, based on a Minimal Residual…

Numerical Analysis · Mathematics 2019-09-11 Thomas Boiveau , Virginie Ehrlacher , Alexandre Ern , Anthony Nouy

In this work we exploit agglomeration based $h$-multigrid preconditioners to speed-up the iterative solution of discontinuous Galerkin discretizations of the Stokes and Navier-Stokes equations. As a distinctive feature $h$-coarsened mesh…

Computational Physics · Physics 2017-09-13 Lorenzo Botti , Alessandro Colombo , Francesco Bassi

We study the solution of large symmetric positive-definite linear systems in a matrix-free setting with a limited iteration budget. We focus on the preconditioned conjugate gradient (PCG) method with spectral preconditioning. Spectral…

Numerical Analysis · Mathematics 2026-04-01 Youssef Diouane , Selime Gürol , Oussama Mouhtal , Dominique Orban

Scaling hyperparameter optimisation to very large datasets remains an open problem in the Gaussian process community. This paper focuses on iterative methods, which use linear system solvers, like conjugate gradients, alternating…

Machine Learning · Computer Science 2025-01-14 Jihao Andreas Lin , Shreyas Padhy , Bruno Mlodozeniec , Javier Antorán , José Miguel Hernández-Lobato

This paper, as the sequel to previous work, develops numerical schemes for fractional diffusion equations on a two-dimensional finite domain with triangular meshes. We adopt the nodal discontinuous Galerkin methods for the full spatial…

Numerical Analysis · Mathematics 2015-07-14 Liangliang Qiu , Weihua Deng , Jan Hesthaven

Iterative solvers for large-scale linear systems such as Krylov subspace methods can diverge when the linear system is ill-conditioned, thus significantly reducing the applicability of these iterative methods in practice for…

Numerical Analysis · Mathematics 2025-07-24 Vasileios Kalantzis , Mark S. Squillante , Chai Wah Wu

In this paper, an efficient solver for the Helmholtz equation using a noval approximation space is developed. The ingradients of the method include the approximation space recently proposed, a discontinuous Galerkin scheme extensively used,…

Numerical Analysis · Mathematics 2025-12-11 Shuhai Zhao

We investigate a numerical behaviour of robust deterministic optimal control problem subject to a convection diffusion equation containing uncertain inputs. Stochastic Galerkin approach, turning the original optimization problem containing…

Numerical Analysis · Mathematics 2023-03-01 Pelin Çiloğlu , Hamdullah Yücel

A preconditioning framework for the coupled problem of frictional contact mechanics and fluid flow in the fracture network is presented. The porous medium is discretized using low-order continuous finite elements, with cell-centered…

Numerical Analysis · Mathematics 2022-05-25 Andrea Franceschini , Laura Gazzola , Massimiliano Ferronato

The generalized polynomial chaos method is applied to the Buckley-Leverett equation. We consider a spatially homogeneous domain modeled as a random field. The problem is projected onto stochastic basis functions which yields an extended…

Numerical Analysis · Mathematics 2016-08-24 Per Pettersson , Hamdi A. Tchelepi

We propose a preconditioner to accelerate the convergence of the GMRES iterative method for solving the system of linear equations obtained from discretize-then-optimize approach applied to optimal control problems constrained by a partial…

Numerical Analysis · Mathematics 2019-11-15 Hamid Mirchi , Davod Khojasteh Salkuyeh

This paper presents the results of a preliminary experimental investigation of the performance of a stationary iterative method based on a block staircase splitting for solving singular systems of linear equations arising in Markov chain…

Numerical Analysis · Mathematics 2023-02-16 V. Besozzi , M. Della Bartola , L. Gemignani

The numerical solution of partial differential equations on high-dimensional domains gives rise to computationally challenging linear systems. When using standard discretization techniques, the size of the linear system grows exponentially…

Numerical Analysis · Mathematics 2015-08-13 Daniel Kressner , Michael Steinlechner , Bart Vandereycken

In this paper we propose a variant of the substructuring preconditioner for solving three-dimensional elliptic-type equations with strongly discontinuous coefficients. In the proposed preconditioner, we use the simplest coarse solver…

Numerical Analysis · Mathematics 2018-01-15 Qiya Hu , Shaoliang Hu

In this note we present a multigrid preconditioning method for solving quadratic optimization problems constrained by a fractional diffusion equation. Multigrid methods within the all-at-once approach to solve the first order-order…

Optimization and Control · Mathematics 2020-10-29 Harbir Antil , Andrei Dr{ă}g{ă}nescu , Kiefer Green

We study preconditioning techniques for discontinuous Galerkin discretizations of isotropic linear elasticity problems in primal (displacement) formulation. We propose subspace correction methods based on a splitting of the vector valued…

Numerical Analysis · Mathematics 2011-11-01 Blanca Ayuso de Dios , Ivan Georgiev , Johannes Kraus , Ludmil Zikatanov

The Schr\"odinger equation defines the dynamics of quantum particles which has been an area of unabated interest in physics. We demonstrate how simple transformations of the Schr\"odinger equation leads to a coupled linear system, whereby…

Numerical Analysis · Computer Science 2015-03-17 Hisham bin Zubair , Bram Reps , Wim Vanroose

Poroelasticity problems play an important role in various engineering, geophysical, and biological applications. Their full discretization results in a large-scale saddle-point system at each time step that is becoming singular for locking…

Numerical Analysis · Mathematics 2025-06-27 Weizhang Huang , Zhuoran Wang