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In this paper we consider a class of robust multilevel precontioners for the Helmholtz equation with high wave number. The key idea in this work is to use the continuous interior penalty finite element methods (CIP-FEM) studied in…

Numerical Analysis · Mathematics 2013-04-26 Huangxin Chen , Haijun Wu , Xuejun Xu

The multigroup neutron transport equations have been widely used to study the motion of neutrons and their interactions with the background materials. Numerical simulation of the multigroup neutron transport equations is computationally…

The solution to the Poisson equation arising from the spectral element discretization of the incompressible Navier-Stokes equation requires robust preconditioning strategies. One such strategy is multigrid. To realize the potential of…

Numerical Analysis · Mathematics 2023-02-27 Malachi Phillips , Paul Fischer

In this paper, we introduce a novel approach to solve the many-body Schrodinger equation by the tensor neural network. Based on the tensor product structure, we can do the direct numerical integration by using fixed quadrature points for…

Computational Physics · Physics 2025-02-27 Yangfei Liao , Zhongshuo Lin , Jianghao Liu , Qingyuan Sun , Yifan Wang , Teng Wu , Hehu Xie , Mingfeng He

We study efficient simulation of steady state for rarefied gas flow, which is modeled by the Boltzmann equation with BGK-type collision term. A nonlinear multigrid solver is proposed to resolve the efficiency issue by the following…

Numerical Analysis · Mathematics 2022-06-28 Zhicheng Hu , Guanghan Li

This study proposes a trainable sampling-based solver for combinatorial optimization problems (COPs) using a deep-learning technique called deep unfolding. The proposed solver is based on the Ohzeki method that combines Markov-chain…

Disordered Systems and Neural Networks · Physics 2024-05-03 Ryo Hagiwara , Satoshi Takabe

The Trotter-Suzuki approximation leads to an efficient algorithm for solving the time-dependent Schr\"odinger equation. Using existing highly optimized CPU and GPU kernels, we developed a distributed version of the algorithm that runs…

Computational Physics · Physics 2013-03-06 Peter Wittek , Fernando M. Cucchietti

We present a robust and efficient multigrid method for single-patch isogeometric discretizations using tensor product B-splines of maximum smoothness. Our method is based on a stable splitting of the spline space into a large subspace of…

Numerical Analysis · Mathematics 2017-08-22 Clemens Hofreither , Stefan Takacs

We present an ab initio approach to solve the time-dependent Schr\"odinger equation to treat electron and photon impact multiple ionization of atoms or molecules. It combines the already known time scaled coordinate method with a new high…

An algorithm for generating optimal nonuniform grids for solving the two-body Schr\"odinger equation is developed and implemented. The shape of the grid is optimized to accurately reproduce the low-energy part of the spectrum of the…

Computational Physics · Physics 2015-05-20 Vladimir Roudnev , Michael Cavagnero

A collision-based hybrid method for the discrete ordinates approximation of the multigroup neutron transport equation is developed for two-dimensional time-dependent problems. At each time step, this algorithm splits the neutron transport…

Computational Physics · Physics 2025-02-17 Ben Whewell , Ryan G. McClarren

We present a fast direct solver for structured linear systems based on multilevel matrix compression. Using the recently developed interpolative decomposition of a low-rank matrix in a recursive manner, we embed an approximation of the…

Numerical Analysis · Mathematics 2014-04-10 Kenneth L. Ho , Leslie Greengard

We introduce a novel Unsmoothed Aggregation (UA) Algebraic Multigrid (AMG) method combined with Preconditioned Conjugate Gradient (PCG) to overcome the limitations of Extended Position-Based Dynamics (XPBD) in high-resolution and…

Graphics · Computer Science 2025-05-20 Chunlei Li , Peng Yu , Tiantian Liu , Siyuan Yu , Yuting Xiao , Shuai Li , Aimin Hao , Yang Gao , Qinping Zhao

A nonlinear multigrid solver for two-phase flow and transport in a mixed fractional-flow velocity-pressure-saturation formulation is proposed. The solver, which is under the framework of the full approximation scheme (FAS), extends our…

Numerical Analysis · Mathematics 2021-09-17 Chak Shing Lee , François P. Hamon , Nicola Castelletto , Panayot S. Vassilevski , Joshua A. White

A multiscale optimization framework for problems over a space of Lipschitz continuous functions is developed. The method solves a coarse-grid discretization followed by linear interpolation to warm-start project gradient descent on…

Numerical Analysis · Mathematics 2026-03-05 Nicholas J. E. Richardson , Noah Marusenko , Michael P. Friedlander

Recent advances in flow-based generative modelling have provided scalable methods for computing the Schr\"odinger Bridge (SB) between distributions, a dynamic form of entropy-regularised Optimal Transport (OT) for the quadratic cost. The…

Machine Learning · Statistics 2025-11-04 Samuel Howard , Peter Potaptchik , George Deligiannidis

Streamline-based quad meshing algorithms use smooth cross fields to partition surfaces into quadrilateral regions by tracing cross field separatrices. In practice, re-entrant corners and misalignment of singularities lead to small regions…

Computational Geometry · Computer Science 2019-08-06 Ryan Viertel , Braxton Osting , Matthew Staten

Understanding the continuous evolution of populations from discrete temporal snapshots is a critical research challenge, particularly in fields like developmental biology and systems medicine where longitudinal tracking of individual…

Machine Learning · Statistics 2025-10-21 Byoungwoo Park , Juho Lee

We propose a hybrid quantum-classical algorithm for solving the time-independent Schr\"odinger equation for atomic and molecular collisions. The algorithm is based on the $S$-matrix version of the Kohn variational principle, which computes…

Quantum Physics · Physics 2023-04-14 Xiaodong Xing , Alejandro Gomez Cadavid , Artur F. Izmaylov , Timur V. Tscherbul

Multilevel techniques are efficient approaches for solving the large linear systems that arise from discretized partial differential equations and other problems. While geometric multigrid requires detailed knowledge about the underlying…

Numerical Analysis · Mathematics 2023-01-23 Tareq. U. Zaman , Scott P. MacLachlan , Luke N. Olson , Matt West