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Related papers: Very Efficient Methods for Multilevel Radiative Tr…

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This study concerns the fast and accurate solution of the line radiation transfer problem, under non-LTE conditions. We propose and evaluate an alternative iterative scheme to the classical ALI-Jacobi method, and to the more recently…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 F. Paletou , E. Anterrieu

A new, very fast method for 3D radiative transfer on fully threaded grids with arbitrarily high angular resolution is presented. The method uses completely cell-based discretization, and is ideally suited for problems with diffuse…

Astrophysics · Physics 2009-11-11 A. O. Razoumov , C. Y. Cardall

Linear kinetic transport equations play a critical role in optical tomography, radiative transfer and neutron transport. The fundamental difficulty hampering their efficient and accurate numerical resolution lies in the high dimensionality…

Numerical Analysis · Mathematics 2021-12-07 Zhichao Peng , Yanlai Chen , Yingda Cheng , Fengyan Li

We address the classical stellar-atmosphere problem and describe our method of numerical solution in detail. The problem consists of the solution of the radiation transfer equation under the constraints of hydrostatic, radiative and…

Astrophysics · Physics 2007-05-23 K. Werner , J. L. Deetjen , S. Dreizler , T. Nagel , T. Rauch , S. L. Schuh

The problem of radio wave reflection from an optically thick plane monotonous layer of magnetized plasma is considered at present work. The plasma electron density irregularities are described by spatial spectrum of an arbitrary form. The…

Plasma Physics · Physics 2009-09-25 N. A. Zabotin , A. G. Bronin

Radiative Transfer (RT) effects play a crucial role in the thermal history of the intergalactic medium. Here I discuss recent advances in the development of numerical methods that introduce RT to cosmological hydrodynamics. These methods…

Astrophysics · Physics 2007-05-23 Tom Abel

We consider the radiation transfer problem in the discrete-ordinate, plane-parallel approach. We introduce two benchmark problems with exact known solutions and show that for strongly non-homogeneous media the homogeneous layers…

Computational Physics · Physics 2007-05-23 M. -P. Zorzano , A. M. Mancho , L. Vazquez

We describe a new algorithm to solve the time dependent, frequency integrated radiation transport (RT) equation implicitly, which is coupled to an explicit solver for equations of magnetohydrodynamics (MHD) using {\sf Athena++}. The…

Instrumentation and Methods for Astrophysics · Physics 2021-04-07 Yan-Fei Jiang

We test the accuracy of the ALI method, widely used in stellar atmosphere modelling, by solving exactly a standard radiative transfer problem in plane-parallel geometry. Some recommendations are given for a practical use of this method.

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

We formulate the problem of a two-level system in a linearly polarized laser field in terms of a nonlinear Riccati-type differential equation and solve the equation analytically in time intervals much shorter than half the optical period.…

Quantum Physics · Physics 2007-05-23 R. Parzynski , M. Sobczak , A. Plucinska

This paper presents nonlinear iterative methods for the fundamental thermal radiative transfer (TRT) model defined by the time-dependent multifrequency radiative transfer (RT) equation and the material energy balance (MEB) equation. The…

Numerical Analysis · Mathematics 2024-09-24 Dmitriy Y. Anistratov

We develop a new numerical scheme for solving the radiative transfer equation in a spherically symmetric system. This scheme does not rely on any kind of diffusion approximation and it is accurate for optically thin, thick, and intermediate…

Instrumentation and Methods for Astrophysics · Physics 2018-05-31 Torsten Stamer , Shu-ichiro Inutsuka

Context: The solution of the nonlocal thermodynamical equilibrium (non-LTE) radiative transfer equation usually relies on stationary iterative methods, which may falsely converge in some cases. Furthermore, these methods are often unable to…

Solar and Stellar Astrophysics · Physics 2015-07-29 Julien Lambert , Eric Josselin , Nils Ryde , Alexandre Faure

Higher resolution telescopes as well as 3D numerical simulations will require the development of detailed 3D radiative transfer calculations. Building upon our previous work we extend our method to include both continuum and line transfer.…

Astrophysics · Physics 2009-11-13 E. Baron , Peter H. Hauschildt

Radiative transfer calculations are essential for modeling planetary atmospheres. However, standard methods are computationally demanding and impose accuracy-speed trade-offs. High computational costs force numerical simplifications in…

Earth and Planetary Astrophysics · Physics 2025-11-03 Isaac Malsky , Tiffany Kataria , Natasha E. Batalha , Matthew Graham

This paper presents an overview of several modeling tools for analyzing molecular line observations at submillimeter wavelengths. These tools are already proving to be very valuable for the interpretation of data from current telescopes,…

Astrophysics · Physics 2007-05-23 Floris van der Tak , Michiel Hogerheijde

The radiation transfer equation is widely used for simulating such as heat transfer in engineering, diffuse optical tomography in healthcare, and radiation hydrodynamics in astrophysics. By combining the lattice Boltzmann method, we propose…

Quantum Physics · Physics 2024-03-11 Asuka Igarashi , Tadashi Kadowaki , Shiro Kawabata

Resonance lines encode rich information about astrophysical sources and their environments, yet fully analytic treatments of multi-line radiative transfer remain almost entirely unexplored. We present exact, closed-form solutions for…

Astrophysics of Galaxies · Physics 2026-02-18 Ethan Stace , Aaron Smith , Kevin Lorinc , Olof Nebrin

In the present paper we consider the problem of resonance line polarization formed in the spherically symmetric expanding atmospheres. For the solution of the concerned polarized transfer equation we use the comoving frame formulation, and…

Solar and Stellar Astrophysics · Physics 2020-01-20 A. Megha , M. Sampoorna , K. N. Nagendra , L. S. Anusha , K. Sankarasubramanian

Scattering of femtosecond laser pulses on resonant transmission and reflection gratings made of dispersive (Drude metals) and dielectric materials is studied by a time-domain numerical algorithm for Maxwell's theory of linear passive…

Computational Physics · Physics 2009-11-10 Andrei G. Borisov , Sergei V. Shabanov