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This paper presents an overview of the radiative transfer problem of calculating the spectral line intensity and polarization that emerges from a (generally magnetized) astrophysical plasma composed of atoms and molecules whose excitation…

Solar and Stellar Astrophysics · Physics 2015-05-14 J. Trujillo Bueno

We derive the radiative transfer equation for arbitrary stationary relativistic flows in stationary spacetimes, i.e. for steady-state transfer problems. We show how the standard characteristics method of solution developed by Mihalas and…

Astrophysics · Physics 2009-11-11 B. Chen , R. Kantowski , E. Baron , S. Knop , P. H. Hauschildt

We have developed an algorithm for transferring radiation in three-dimensional space. The algorithm computes radiation source and sink terms using the Fast Fourier Transform (FFT) method, based on a formulation in which the integral of any…

Astrophysics · Physics 2009-11-07 Renyue Cen

We consider the iterative solution of anisotropic radiative transfer problems using residual minimization over suitable subspaces. We show convergence of the resulting iteration using Hilbert space norms, which allows us to obtain…

Numerical Analysis · Mathematics 2025-05-28 Riccardo Bardin , Matthias Schlottbom

Numerical discretization of the large-scale Maxwell's equations leads to an ill-conditioned linear system that is challenging to solve. The key requirement for successive solutions of this linear system is to choose an efficient solver. In…

Numerical Analysis · Mathematics 2023-01-31 Sahar Borzooei , Victorita Dolean , Pierre-Henri Tournier , Claire Migliaccio

The calculation of internal atmospheric (longwave) fluxes is a key component of any model of exoplanet atmospheres that requires radiative-transfer (RT) calculations. For atmospheres containing a strong scattering component such as cloud…

Earth and Planetary Astrophysics · Physics 2024-02-28 Elspeth K. H. Lee

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

Path integral-based simulation methodologies play a crucial role for the investigation of nuclear quantum effects by means of computer simulations. However, these techniques are significantly more demanding than corresponding classical…

Statistical Mechanics · Physics 2018-01-17 Karsten Kreis , Kurt Kremer , Raffaello Potestio , Mark E. Tuckerman

We show that a vapor of multilevel atoms driven by far-off resonant laser beams, with possibility of interference of two Raman resonances, is highly efficient for creating parity-time (PT) symmetric profiles of the probe-field refractive…

Optics · Physics 2015-06-12 Chao Hang , Guoxiang Huang , Vladimir V. Konotop

Two-frequency radiative transfer (2f-RT) theory is developed for classical waves in random media. Depending on the ratio of the wavelength to the scale of medium fluctuation 2f-RT equation is either a Boltzmann-like integral equation with a…

Optics · Physics 2009-11-13 Albert C. Fannjiang

We describe a code designed for hot media {(T $\ge$} a few 10$^4$ K), optically thick to Compton scattering. It computes the structure of a plane-parallel slab of gas in thermal and ionization equilibrium, illuminated on one side or on both…

Astrophysics · Physics 2009-09-25 Anne-Marie Dumont , Suzy Collin

Using a shared microwave resonator, we propose a transduction scheme between superconducting qubits and qubit states encoded in the low-lying internal levels of trapped atomic systems. The approach employs atomic Rydberg levels together…

Quantum Physics · Physics 2025-09-18 Fernando L. Semião , Matthias Keller

Consider an algebraic two-level method applied to the $n$-dimensional linear system $A \mathbf{x} = \mathbf{b}$ using fine-space preconditioner (i.e., ``relaxation'' or ``smoother'') $M$, with $M \approx A$, restriction and interpolation…

Numerical Analysis · Mathematics 2025-09-12 Oliver A. Krzysik , Ben S. Southworth , Golo A. Wimmer , Ahsan Ali , James Brannick , Karsten Kahl

Accurate accounting of particle number and 4-momentum in radiative transfer may be facilitated by the use of transport equations that allow transparent conversion between volume and surface integrals in both spacetime and momentum space.…

Astrophysics · Physics 2016-11-09 Christian Y. Cardall

In this paper, we study the bidirectional/two-way relaying of molecular communication and propose a relaying scheme with two time slots. Compared to the four-time-slot and three-time-slot schemes, the proposed two-time-slot scheme improves…

Emerging Technologies · Computer Science 2017-11-09 Md. Noor-A-Rahim , MD Nashid Anjum , Guan Yong Liang

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

The radiative transfer equation models the interaction of radiation with scattering and absorbing media and has important applications in various fields in science and engineering. It is an integro-differential equation involving time,…

Numerical Analysis · Mathematics 2020-04-20 Min Zhang , Juan Cheng , Weizhang Huang , Jianxian Qiu

This paper deals also with a problem of gas absorption accompanied by an instantaneous, irreversible reaction in the liquid layer. The well-known methods for calculating such processes are based usually on the certain amendments to…

Computational Engineering, Finance, and Science · Computer Science 2015-06-04 A. M. Brener , L. M. Musabekova

A new approach for integration of motion in many-body systems of interacting polyatomic molecules is proposed. It is based on splitting time propagation of pseudo-variables in a modified phase space, while the real translational and…

Statistical Mechanics · Physics 2009-11-13 Igor P. Omelyan

A method for the fast and accurate solution of the radiative transfer equation in plane-parallel media with coherent isotropic scattering is presented. This largely analytical approach uses the formalism of meromorphic functions in order to…

Astrophysics · Physics 2007-05-23 G. V. Efimov , N. V. Kryzhevoi , W. von Waldenfels , R. Wehrse