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Within the framework of $ p $-adaptive flux reconstruction, we aim to construct efficient polynomial multigrid ($p$MG) preconditioners for implicit time integration of the Navier--Stokes equations using Jacobian-free Newton--Krylov (JFNK)…

Numerical Analysis · Mathematics 2022-02-22 Lai Wang , Will Trojak , Freddie Witherden , Antony Jameson

Fully realizing the potential of multigrid solvers often requires custom algorithms for a given application model, discretizations and even regimes of interest, despite considerable effort from the applied math community to develop fully…

Plasma Physics · Physics 2023-02-22 Mark F. Adams , Matthew K. Knepley

This paper presents a new computer code to solve the general relativistic magnetohydrodynamics (GRMHD) equations using distributed parallel adaptive mesh refinement (AMR). The fluid equations are solved using a finite difference Convex ENO…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Matthew Anderson , Eric Hirschmann , Steven L. Liebling , David Neilsen

HII regions powered by ionizing radiation from massive stars drive the dynamical evolution of the interstellar medium. Fast radiative transfer methods for incorporating photoionization effects are thus essential in astrophysical…

Instrumentation and Methods for Astrophysics · Physics 2025-02-25 Cheryl S. C. Lau , Maya A. Petkova , Ian A. Bonnell

The paper focuses on developing and studying efficient block preconditioners based on classical algebraic multigrid for the large-scale sparse linear systems arising from the fully coupled and implicitly cell-centered finite volume…

Numerical Analysis · Mathematics 2021-02-03 Xiaoqiang Yue , Shulei Zhang , Xiaowen Xu , Shi Shu , Weidong Shi

We propose a seamless multiscale method which approximates the macroscopic behavior of the passive advection-diffusion equations with steady incompressible velocity fields with multi-spatial scales. The method uses decompositions of the…

Numerical Analysis · Mathematics 2016-06-22 Yoonsang Lee , Bjorn Engquist

Identifying the discontinuous diffusion coefficient in an elliptic equation with observation data of the gradient of the solution is an important nonlinear and ill-posed inverse problem. Models with total variational (TV) regularization…

Numerical Analysis · Mathematics 2021-09-01 Wenyi Tian , Xiaoming Yuan , Hangrui Yue

A new numerical code, called SFUMATO, for solving self-gravitational magnetohydrodynamics (MHD) problems using adaptive mesh refinement (AMR) is presented. A block-structured grid is adopted as the grid of the AMR hierarchy. The total…

Astrophysics · Physics 2015-06-24 Tomoaki Matsumoto

Current Adaptive Mesh Refinement (AMR) simulations require algorithms that are highly parallelized and manage memory efficiently. As compute engines grow larger, AMR simulations will require algorithms that achieve new levels of efficient…

Solar and Stellar Astrophysics · Physics 2015-03-19 Jonathan J. Carroll-Nellenback , Brandon Shroyer , Adam Frank , Chen Ding

Due to its accuracy and generality, Monte Carlo radiative transfer (MCRT) has emerged as the prevalent method for Ly$\alpha$ radiative transfer in arbitrary geometries. The standard MCRT encounters a significant efficiency barrier in the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Aaron Smith , Benny T. -H. Tsang , Volker Bromm , Milos Milosavljevic

Simulating spatiotemporal turbulence with high fidelity remains a cornerstone challenge in computational fluid dynamics (CFD) due to its intricate multiscale nature and prohibitive computational demands. Traditional approaches typically…

Fluid Dynamics · Physics 2024-07-01 Xiantao Fan , Deepak Akhare , Jian-Xun Wang

This paper presents the development of an Adaptive Algebraic Multiscale Solver for Compressible flow (C-AMS) in heterogeneous porous media. Similar to the recently developed AMS for incompressible (linear) flows [Wang et al., JCP, 2014],…

Numerical Analysis · Mathematics 2017-05-17 Matei Tene , Yixuan Wang , Hadi Hajibeygi

We present an adaptive scheme for isogeometric phase-field modeling, to perform suitably graded hierarchical refinement and coarsening on both single- and multi-patch geometries by considering truncated hierarchical spline constructions…

Numerical Analysis · Mathematics 2023-06-13 Cesare Bracco , Carlotta Giannelli , Alessandro Reali , Michele Torre , Rafael Vázquez

Diffusion models (DMs) have achieved state-of-the-art generative performance but suffer from high sampling latency due to their sequential denoising nature. Existing solver-based acceleration methods often face image quality degradation…

Computer Vision and Pattern Recognition · Computer Science 2025-07-22 Beier Zhu , Ruoyu Wang , Tong Zhao , Hanwang Zhang , Chi Zhang

The paper investigates a non-intrusive parallel time integration with multigrid for space-fractional diffusion equations in two spatial dimensions. We firstly obtain a fully discrete scheme via using the linear finite element method to…

Numerical Analysis · Mathematics 2018-05-18 Xiaoqiang Yue , Shi Shu , Xiaowen Xu , Weiping Bu , Kejia Pan

We develop an asymptotic preserving scheme for the gray radiative transfer equation. Two asymptotic regimes are considered: one is a diffusive regime described by a nonlinear diffusion equation for the material temperature; the other is a…

Numerical Analysis · Mathematics 2019-09-17 Min Tang , Li Wang , Xiaojiang Zhang

We study an element agglomeration coarsening strategy that requires data redistribution at coarse levels when the number of coarse elements becomes smaller than the used computational units (cores). The overall procedure generates coarse…

Numerical Analysis · Mathematics 2025-12-01 Hillary R. Fairbanks , Delyan Z. Kalchev , Chak Shing Lee , Panayot S. Vassilevski

We study Hibridizable Discontinuous Galerkin (HDG) discretizations for a class of non-linear interior elliptic boundary value problems posed in curved domains where both the source term and the diffusion coefficient are non-linear. We…

Numerical Analysis · Mathematics 2021-12-30 Nestor Sánchez , Tonatiuh Sánchez-Vizuet , Manuel E. Solano

Existing LiDAR-Camera fusion methods have achieved strong results in 3D object detection. To address the sparsity of point clouds, previous approaches typically construct spatial pseudo point clouds via depth completion as auxiliary input…

Computer Vision and Pattern Recognition · Computer Science 2025-08-28 Jijun Wang , Yan Wu , Yujian Mo , Junqiao Zhao , Jun Yan , Yinghao Hu

The increasing complexity and scale of photonic and electromagnetic devices demand efficient and accurate numerical solvers. In this work, we develop a parallel overlapping domain decomposition method (DDM) based on the finite-difference…

Optics · Physics 2025-09-26 Zhanwen Wang , Chengnian Huang , Wangtao Lu , Yuntian Chen , Wei E. I. Sha