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Radiative transfer is a key component in almost all astrophysical and cosmological simulations. We present Magritte: a modern open-source software library for 3D radiative transfer. It uses a deterministic ray-tracer and formal solver, i.e.…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Frederik De Ceuster , Ward Homan , Jeremy Yates , Leen Decin , Peter Boyle , James Hetherington

In this paper, the physical conditions within the inhomogeneous solar atmosphere have been reconstructed by means of solving the inverse problem of Non Local Thermodynamic Equilibrium (NLTE) radiative transfer. The profiles of…

Astrophysics · Physics 2008-11-26 M. I. Stodilka , S. Z. Malynych

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

We present a numerical implementation for the solution of the relativistic radiation hydrodynamics and magnetohydrodynamics equations, designed as an independent module within the freely available code PLUTO. The radiation transfer…

Instrumentation and Methods for Astrophysics · Physics 2019-06-19 Julio David Melon Fuksman , Andrea Mignone

In a classical scattering problem, the classical eikonal is defined as the generator of the canonical transformation that maps in-states to out-states. It can be regarded as the classical limit of the log of the quantum S-matrix. In a…

High Energy Physics - Theory · Physics 2025-01-28 Joon-Hwi Kim , Jung-Wook Kim , Sungsoo Kim , Sangmin Lee

A system of nonlocal electron-transport equations for small perturbations in a magnetized plasma is derived using the systematic closure procedure of V. Yu. Bychenkov et al., Phys. Rev. Lett. 75, 4405 (1995). Solution to the linearized…

Plasma Physics · Physics 2009-11-10 A. V. Brantov , V. Yu. Bychenkov , W. Rozmus , C. E. Capjack , R. Sydora

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

In the present paper we consider the full nonlocal thermodynamic equilibrium (non-LTE) radiation transfer problem. This formalism allows us to account for deviation from equilibrium distribution of both the radiation field and the massive…

Solar and Stellar Astrophysics · Physics 2024-10-09 M. Sampoorna , F. Paletou , V. Bommier , T. Lagache

Aims. We examined the capabilities of methods based on the weak-field approximation and line bisectors to extract fast and reliable information about the height stratification of the magnetic field and line-of-sight velocities,…

Solar and Stellar Astrophysics · Physics 2025-03-18 A. L. Siu-Tapia , L. R. Bellot Rubio , D. Orozco Suárez

We consider the classical integral equation reformulation of the radiative transport equation (RTE) in a heterogeneous medium, assuming isotropic scattering. We prove an estimate for the norm of the integral operator in this formulation…

Numerical Analysis · Mathematics 2019-03-21 J. C. H. Blake , I. G. Graham , F. Scheben , A. Spence

In the present article, we discuss a numerical method of solution for the so-called "full non-LTE" radiation transfer problem, basic formalism of which was revisited by Paletou & Peymirat (2021; see also Oxenius 1986). More specifically,…

Instrumentation and Methods for Astrophysics · Physics 2023-03-15 F. Paletou , M. Sampoorna , C. Peymirat

The Lorentz transformations are represented by Einstein velocity addition on the ball of relativistically admissible velocities. This representation is by projective maps. The Lie algebra of this representation defines the relativistic…

General Relativity and Quantum Cosmology · Physics 2011-08-17 Yaakov Friedman

We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and…

Earth and Planetary Astrophysics · Physics 2015-06-19 Kevin Heng , João M. Mendonça , Jae-Min Lee

A new approach, which is based on the new canonical equations of Hamilton found by us recently, is presented to analytically obtain the approximate solution of the nonlocal nonlinear Schr\"{o}dinger equation (NNLSE). The approximate…

Pattern Formation and Solitons · Physics 2015-06-03 Guo Liang , Qi Guo , Yingbing Li , Zhanmei Ren

In this work, we introduce a fast numerical algorithm to solve the time-dependent radiative transport equation (RTE). Our method uses the integral formulation of RTE and applies the treecode algorithm to reduce the computational complexity…

Numerical Analysis · Mathematics 2020-01-29 Hongkai Zhao , Yimin Zhong

We describe a new hybrid framework to model non-thermal spectral signatures from highly energetic particles embedded in a large-scale classical or relativistic MHD flow. Our method makes use of \textit{Lagrangian} particles moving through…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Bhargav Vaidya , Andrea Mignone , Gianluigi Bodo , Paola Rossi , Silvano Massaglia

This paper presents an analytical framework for the study of scattering and diffraction phenomena in spacetime-modulated metallic gratings. Using a Lorentz transformation, it is shown that a particular class of spacetime-modulated gratings…

Applied Physics · Physics 2023-08-01 Antonio Alex-Amor , Carlos Molero , Mário G. Silveirinha

Modeling the variability of the solar spectral irradiance is a key factor for understanding the solar influence on the climate of the Earth. As a first step to calculating the solar spectral irradiance variations we reproduce the solar…

Astrophysics · Physics 2009-11-13 M. Haberreiter , W. Schmutz , I. Hubeny

We consider the radiative transfer problem in a plane-parallel slab of thermal electrons in the presence of an overcritical magnetic field. Under such conditions, the magnetic field behaves as a birefringent medium for the propagating…

High Energy Astrophysical Phenomena · Physics 2019-08-19 C. Ceccobello , R. Farinelli , L. Titarchuk

Based on our previous work for solving the nonlinear Schrodinger equation with multichannel dynamics that is given by a localized standing wave and radiation, in this work we deal with the multichannel solution which consists of a moving…

Pattern Formation and Solitons · Physics 2016-03-23 Avy Soffer , Xiaofei Zhao