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Adaptive meshing is a fundamental component of adaptive finite element methods. This includes refining and coarsening meshes locally. In this work, we are concerned with the red-green-blue refinement strategy in two dimensions and its…

Numerical Analysis · Mathematics 2020-10-13 Stefan A. Funken , Anja Schmidt

A new cosmological multidimensional hydrodynamic and N-body code based on an Adaptive Mesh Refinement scheme is described and tested. The hydro part is based on modern high-resolution shock-capturing techniques, whereas N-body approach is…

Astrophysics · Physics 2009-11-10 Vicent Quilis

The estimation of normalizing constants is a fundamental step in probabilistic model comparison. Sequential Monte Carlo methods may be used for this task and have the advantage of being inherently parallelizable. However, the standard…

Machine Learning · Statistics 2016-08-16 Marco Fraccaro , Ulrich Paquet , Ole Winther

Block-structured AMR meshes are often used in astrophysical fluid simulations, where the geometry of the domain is simple. We consider potential efficiency gains for time sub-cycling, or time refinement (TR), on Berger-Collela and oct-tree…

Astrophysics · Physics 2007-05-23 L. J. Dursi , M. Zingale

In this work we consider a relativistic drift-kinetic model for runaway electrons along with a Fokker-Planck operator for small-angle Coulomb collisions, a radiation damping operator, and a secondary knock-on (Boltzmann) collision source.…

Numerical Analysis · Mathematics 2024-03-22 Johann Rudi , Max Heldman , Emil M. Constantinescu , Qi Tang , Xian-Zhu Tang

An implicit neural representation (INR) is a neural network that approximates a spatiotemporal function. Many memory-intensive visualization tasks, including modern 4D CT scanning methods, represent data natively as INRs. While INRs are…

Machine Learning · Computer Science 2025-12-03 Jennifer Zvonek , Andrew Gillette

Implicit Neural Representations (INRs), characterized by neural network-encoded signed distance fields, provide a powerful means to represent complex geometries continuously and efficiently. While successful in computer vision and…

Computational Engineering, Finance, and Science · Computer Science 2025-07-09 Samundra Karki , Ming-Chen Hsu , Adarsh Krishnamurthy , Baskar Ganapathysubramanian

We implement adaptive mesh refinement (AMR) simulations of global topological strings using the public code, GRChombo. We perform a quantitative investigation of massive radiation from single sinusoidally displaced string configurations,…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-10 Amelia Drew , E. P. S. Shellard

A new code and methodology are introduced for solving the general relativistic magnetohydrodynamic (GRMHD) equations in fixed background spacetimes using time-explicit, finite-volume discretization. The code has options for solving the…

Astrophysics · Physics 2009-11-13 Peter Anninos , P. Chris Fragile , Jay D. Salmonson

This paper presents a methodology to learn surrogate models of steady state fluid dynamics simulations on meshed domains, based on Implicit Neural Representations (INRs). The proposed models can be applied directly to unstructured domains…

Computational Engineering, Finance, and Science · Computer Science 2024-10-29 Giovanni Catalani , Siddhant Agarwal , Xavier Bertrand , Frederic Tost , Michael Bauerheim , Joseph Morlier

We propose an adaptive regularization scheme in a variational framework where a convex composite energy functional is optimized. We consider a number of imaging problems including denoising, segmentation and motion estimation, which are…

Computer Vision and Pattern Recognition · Computer Science 2017-03-01 Byung-Woo Hong , Ja-Keoung Koo , Hendrik Dirks , Martin Burger

Methods to solve the relativistic hydrodynamic equations are a key computational kernel in a large number of astrophysics simulations and are crucial to understanding the electromagnetic signals that originate from the merger of…

Instrumentation and Methods for Astrophysics · Physics 2015-12-02 Jackson DeBuhr , Bo Zhang , Matthew Anderson , David Neilsen , Eric W. Hirschmann

As supercomputers advance towards exascale capabilities, computational intensity increases significantly, and the volume of data requiring storage and transmission experiences exponential growth. Adaptive Mesh Refinement (AMR) has emerged…

Distributed, Parallel, and Cluster Computing · Computer Science 2023-07-20 Daoce Wang , Jesus Pulido , Pascal Grosset , Jiannan Tian , Sian Jin , Houjun Tang , Jean Sexton , Sheng Di , Zarija Lukić , Kai Zhao , Bo Fang , Franck Cappello , James Ahrens , Dingwen Tao

We present a description of the adaptive mesh refinement (AMR) implementation of the PLUTO code for solving the equations of classical and special relativistic magnetohydrodynamics (MHD and RMHD). The current release exploits, in addition…

High Energy Astrophysical Phenomena · Physics 2015-05-30 A. Mignone , C. Zanni , P. Tzeferacos , B. van Straalen , P. Colella , G. Bodo

We present a new code, SCALAR, based on the high-resolution hydrodynamics and N-body code RAMSES, to solve the Schr\"odinger equation on adaptive refined meshes. The code is intended to be used to simulate axion or fuzzy dark matter models…

Computational Physics · Physics 2020-09-23 Mattia Mina , David F. Mota , Hans A. Winther

The physical characteristics and evolution of a large-scale helium plume are examined through a series of numerical simulations with increasing physical resolution using adaptive mesh refinement (AMR). The five simulations each model a 1~m…

A description is given of the algorithms implemented in the AstroBEAR adaptive mesh refinement code for ideal magnetohydrodynamics. The code provides several high resolution, shock capturing schemes which are constructed to maintain…

Astrophysics · Physics 2009-06-23 Andrew J. Cunningham , Adam Frank , Peggy Varniere , Sorin Mitran , Thomas W. Jones

We present a new three-dimensional general-relativistic hydrodynamic evolution scheme coupled to dynamical spacetime evolutions which is capable of efficiently simulating stellar collapse, isolated neutron stars, black hole formation, and…

High Energy Astrophysical Phenomena · Physics 2013-09-23 C. Reisswig , R. Haas , C. D. Ott , E. Abdikamalov , P. Moesta , D. Pollney , E. Schnetter

We present the first high order one-step ADER-WENO finite volume scheme with Adaptive Mesh Refinement (AMR) in multiple space dimensions. High order spatial accuracy is obtained through a WENO reconstruction, while a high order one-step…

Numerical Analysis · Mathematics 2015-03-11 Michael Dumbser , Olindo Zanotti , Arturo Hidalgo , Dinshaw S. Balsara

This article investigates the convergence properties of a relative-type inexact preconditioned proximal augmented Lagrangian method (rip$^2$ALM) for convex nonlinear programming, a fundamental class of optimization problems with broad…

Optimization and Control · Mathematics 2026-03-31 Lei Yang , Jiayi Zhu , Ling Liang , Kim-Chuan Toh