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Related papers: Multigrid Methods for Polarized Radiative Transfer

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This article gives an analysis of the behavior of polarizing grids and reflecting polarizers by solving Maxwell's equations, for arbitrary angles of incidence and grid rotation, for cases where the excitation is provided by an incident…

The simulation of high-dimensional problems with manageable computational resource represents a long-standing challenge. In a series of our recent work [25, 17, 18, 24], a class of sparse grid DG methods has been formulated for solving…

Numerical Analysis · Mathematics 2019-06-27 Wei Guo

We propose a multiscale approach for a nonlinear Helmholtz problem with possible oscillations in the Kerr coefficient, the refractive index, and the diffusion coefficient. The method does not rely on structural assumptions on the…

Numerical Analysis · Mathematics 2021-12-10 Roland Maier , Barbara Verfürth

A numerical algorithm for solving mantle convection problems with strongly variable viscosity is presented. Equations for conservation of mass and momentum for highly viscous and incompressible fluids are solved iteratively by a multigrid…

Geophysics · Physics 2009-11-10 Masanori Kameyama , Akira Kageyama , Tetsuya Sato

We present a general formalism for computing self-consistent, numerical solutions to the time-dependent radiative transfer equation in low velocity, multi-level ions undergoing radiative interactions. Recent studies of time-dependent…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Matthew van Adelsberg , Rosalba Perna

Context. Three-dimensional non-local thermodynamical equilibrium (NLTE) radiative transfer calculations are a fundamental tool for a detailed spectral analysis in stellar atmospheres, but require vast amounts of computer power. This…

Solar and Stellar Astrophysics · Physics 2023-07-12 Elias R. Udnæs , Tiago M. D. Pereira

Terahertz chiral sensing and polarization-multiplexing communication demand subwavelength devices that dynamically invert polarization helicity. Metasurfaces can enhance anisotropy and fine tunability at subwavelength scales for this…

This paper is concerned with developing an efficient numerical algorithm for fast implementation of the sparse grid method for computing the $d$-dimensional integral of a given function. The new algorithm, called the MDI-SG ({\em multilevel…

Numerical Analysis · Mathematics 2022-10-27 Huicong Zhong , Xiaobing Feng

This paper deals with the efficient numerical solution of single-phase flow problems in fractured porous media. A monolithic multigrid method is proposed for solving two-dimensional arbitrary fracture networks with vertical and/or…

Numerical Analysis · Mathematics 2018-11-06 Andrés Arrarás , Francisco J. Gaspar , Laura Portero , Carmen Rodrigo

Computing at the exascale level is expected to be affected by a significantly higher rate of faults, due to increased component counts as well as power considerations. Therefore, current day numerical algorithms need to be reexamined as to…

Numerical Analysis · Mathematics 2019-05-27 Mark Ainsworth , Christian Glusa

Subwavelength grating micro-polarizer arrays, as a type of focal plane division simultaneous detection method, are significantly advancing the development and practical application of polarization imaging technology. Based on the…

Optics · Physics 2024-10-17 Tianshi Lu , Fuyuan Deng , Yufeng Wei , Zhipeng Zeng , Xinghui Li

We solved the radiative transfer and statistical equilibrium equations in a two-dimensional cross-section of a cylindrical structure oriented horizontally and lying above the solar surface. The cylinder is filled with a mixture of hydrogen…

Solar and Stellar Astrophysics · Physics 2016-03-02 N. Labrosse , A. S. Rodger

An expression for the partial frequency redistribution (PRD) matrix for line scattering in a two-term atom, which includes the J-state interference between its fine structure line components is derived. The influence of collisions (both…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. N. Smitha , K. N. Nagendra , M. Sampoorna , J. O. Stenflo

In this paper we propose a multigrid optimization algorithm (MG/OPT) for the numerical solution of a class of quasilinear variational inequalities of the second kind. This approach is enabled by the fact that the solution of the variational…

Numerical Analysis · Mathematics 2022-05-24 Sergio González-Andrade , Sofía López

We introduce a geometric multigrid method for solving linear systems arising from variational problems on surfaces in geometry processing, Gravo MG. Our scheme uses point clouds as a reduced representation of the levels of the multigrid…

Computational Geometry · Computer Science 2023-07-12 Ruben Wiersma , Ahmad Nasikun , Elmar Eisemann , Klaus Hildebrandt

We present an iterative method to diagonalise large matrices. The basic idea is the same as the conjugated gradient (CG) method, i.e, minimizing the Rayleigh quotient via its gradient and avoiding reintroduce errors to the directions of…

Computational Physics · Physics 2009-11-10 Quanlin Jie , Dunhuan Liu

Several practical multi-user multi-carrier communication systems are characterized by a multi-carrier interference channel system model where the interference is treated as noise. For these systems, spectrum optimization is a promising…

Information Theory · Computer Science 2013-08-28 Paschalis Tsiaflakis , François Glineur

A multilevel kernel-based interpolation method, suitable for moderately high-dimensional function interpolation problems, is proposed. The method, termed multilevel sparse kernel-based interpolation (MLSKI, for short), uses both level-wise…

Numerical Analysis · Mathematics 2012-04-19 Emmanuil H. Georgoulis , Jeremy Levesley , Fazli Subhan

We study a multigrid method for solving large linear systems of equations with tensor product structure. Such systems are obtained from stochastic finite element discretization of stochastic partial differential equations such as the…

Numerical Analysis · Mathematics 2017-04-11 Howard C. Elman , Tengfei Su

Microgrids are recognized as a relevant tool to absorb decentralized renewable energies in the energy mix. However, the sequential handling of multiple stochastic productions and demands, and of storage, make their management a delicate…

Optimization and Control · Mathematics 2021-06-09 François Pacaud , Michel de Lara , Jean-Philippe Chancelier , Pierre Carpentier