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Related papers: A 3D radiative transfer framework: II. line transf…

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We consider the inverse problem of reconstructing the scattering coefficient of a simple radiative transport equation (RTE) used to model light propagation inside a scattering medium. To do so, we extract information from the second term in…

Analysis of PDEs · Mathematics 2025-08-07 Francis Chung , Faith Hensley

Background: Path integrals are a powerful tool for solving problems in quantum theory that are not amenable to a treatment by perturbation theory. Most path integral computations require an analytic continuation to imaginary time. While…

Nuclear Theory · Physics 2020-07-01 W. N. Polyzou , Ekaterina Nathanson

A new dynamic system approach to the problem of radiative transfer inside scattering and absorbing media is presented, directly based on firsthand physical principles. This method, the Dynamic Radiative Transfer System (DRTS), calculates…

Statistical Mechanics · Physics 2018-01-12 Anastasios Georgakopoulos , Konstantinos Politopoulos , Efstratios Georgiou

We present a high-order accurate boundary-based solver for three-dimensional (3D) frequency-domain scattering from a doubly-periodic grating of smooth axisymmetric sound-hard or transmission obstacles. We build the one-obstacle solution…

Numerical Analysis · Mathematics 2016-09-21 Yuxiang Liu , Alex H. Barnett

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

The emergence of three-dimensional magneto-hydrodynamic (MHD) simulations of stellar atmospheres has sparked a need for efficient radiative transfer codes to calculate detailed synthetic spectra. We present RH 1.5D, a massively parallel…

Solar and Stellar Astrophysics · Physics 2015-01-21 Tiago M. D. Pereira , Han Uitenbroek

As a follow up to \cite{Causley2013}, we provide a detailed description of the numerical implementation of an O(N), A-stable, second order accurate solution of the wave equation, constructed from semi-discrete boundary value problems. We…

Numerical Analysis · Mathematics 2013-07-01 Matthew F. Causley , Andrew J. Christlieb , Yaman Guclu , Eric Wolf

This paper considers the iterative solution of linear systems arising from discretization of the anisotropic radiative transfer equation with discontinuous elements on the sphere. In order to achieve robust convergence behavior in the…

Numerical Analysis · Mathematics 2021-03-11 Jürgen Dölz , Olena Palii , Matthias Schlottbom

We introduce the radiative transfer code Sweep for the cosmological simulation suite Arepo. Sweep is a discrete ordinates method in which the radiative transfer equation is solved under the infinite speed of light, steady state assumption…

Instrumentation and Methods for Astrophysics · Physics 2023-01-25 Toni Peter , Ralf S. Klessen , Guido Kanschat , Simon C. O. Glover , Peter Bastian

The aim of this paper is to develop a mathematical framework for opto-elastography. In opto-elastography, a mechanical perturbation of the medium produces a decorrelation of optical speckle patterns due to the displacements of optical…

Mathematical Physics · Physics 2013-06-19 Habib Ammari , Emmanuel Bossy , Josselin Garnier , Wenjia Jing , Laurent Seppecher

The discussion regarding the numerical integration of the polarized radiative transfer equation is still open and the comparison between the different numerical schemes proposed by different authors in the past is not fully clear. Aiming at…

Solar and Stellar Astrophysics · Physics 2017-09-06 Gioele Janett , Edgar S. Carlin , Oskar Steiner , Luca Belluzzi

Oxygen is the most abundant element on the Sun after Hydrogen and Helium. The intensity spectrum of resonance lines of neutral Oxygen namely O {\sc i} (1302, 1305 and 1306 \AA\,) has been studied in the literature for chromospheric…

Solar and Stellar Astrophysics · Physics 2015-06-22 L. S. Anusha , K. N. Nagendra , H. Uitenbroek

We come back to the analytical solution of the standard transfer problem in a stellar atmosphere. It consists in solving the radiative transfer equation in a homogeneous and isothermal plane-parallel atmosphere, with light scattering taken…

Astrophysics · Physics 2007-05-23 L. Chevallier , B. Rutily

Recently, with the advances in computational speed and availability there has been a growth in the number and resolution of fully 3-D hydrodynamical simulations. However, all of these simulations are purely hydrodynamical and there has been…

Astrophysics · Physics 2009-11-10 E. Baron , Peter H. Hauschildt

We introduce a layer potential representation for the solution of the transmission problem defined by two dielectric channels, or open wave-guides, meeting along the straight-line interface, $\{x_1=0\}.$ The main observation is that the…

Mathematical Physics · Physics 2025-11-11 Charles L. Epstein

We report the development of a new ray-tracing simulation tool having the potential of the full characterization of a radio link through the accurate study of the propagation path of the signal from the transmitting to the receiving…

Computational Physics · Physics 2007-05-23 C. Tannous , J. Nigrin

One of the main computational drawbacks in the application of 3-D iterative inversion techniques is the requirement of solving the field quantities for the updated contrast in every iteration. In this paper, the 3-D electromagnetic inverse…

Signal Processing · Electrical Eng. & Systems 2019-06-27 Shilong Sun , Bert Jan Kooij , Alexander G. Yarovoy

We demonstrate a motion-free intensity diffraction tomography technique that enables direct inversion of 3D phase and absorption from intensity-only measurements for weakly scattering samples. We derive a novel linear forward model,…

Image and Video Processing · Electrical Eng. & Systems 2018-06-26 Ruilong Ling , Waleed Tahir , Hsing-Ying Lin , Hakho Lee , Lei Tian

In a recent article the authors showed that the radiative Transfer equations with multiple frequencies and scattering can be formulated as a nonlinear integral system. In the present article, the formulation is extended to handle reflective…

Numerical Analysis · Mathematics 2023-06-12 Olivier Pironneau , Pierre-Henri Tournier

We present a new parallel model of computation suitable for spatial architectures, for which the energy used for communication heavily depends on the distance of the communicating processors. In our model, processors have locations on a…

Data Structures and Algorithms · Computer Science 2023-01-18 Lukas Gianinazzi , Tal Ben-Nun , Maciej Besta , Saleh Ashkboos , Yves Baumann , Piotr Luczynski , Torsten Hoefler