English
Related papers

Related papers: Fast multilevel radiative transfer

200 papers

We present a new method for computing the transverse transfer matrix through superimposed axisymmetric RF and solenoid field maps. The algorithm constructs the transfer matrix directly from one dimensional RF and solenoid field maps without…

Accelerator Physics · Physics 2011-07-21 Colwyn Gulliford , Ivan Bazarov

A radiative transfer scheme is presented, based on a moment description of the equation of radiative transfer and the so-called ``M1 closure model'' for the Eddington tensor. This model features a strictly hyperbolic transport step for…

Astrophysics · Physics 2009-11-13 Dominique Aubert , Romain Teyssier

In this paper we discuss numerical methods and algorithms for the solution of NLTE stellar atmosphere problems involving expanding atmospheres, e.g., found in novae, supernovae and stellar winds. We show how a scheme of nested iterations…

Astrophysics · Physics 2011-06-02 P. H. Hauschildt , E. Baron

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

For numerical simulations of highly relativistic and transversely accelerated charged particles including radiation fast algorithms are needed. While the radiation in particle accelerators has wavelengths in the order of 100 um the…

Computational Physics · Physics 2015-05-28 Christof Kraus , Andreas Adelmann , Peter Arbenz

We consider the influence of acceleration on the radiative energy shifts of atoms in Minkowski space. We study a two-level atom coupled to a scalar quantum field. Using a Heisenberg picture approach, we are able to separate the…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Juergen Audretsch , Rainer Mueller

Two new intermediary orbits of the artificial satellite problem are proposed. The analytical solutions include higher order effects of the Geopotential, and are obtained by means of a torsion transformation applied to the quasi-Keplerian…

Dynamical Systems · Mathematics 2016-12-28 Denis Hautesserres , Martin Lara

A tutorial associated with the distribution of 2D non-LTE multilevel atom radiative transfer codes.

Instrumentation and Methods for Astrophysics · Physics 2019-03-15 F. Paletou , L. Léger , M. Chane-Yook , L. H. Auer

The present work proposes a self-consistent reduced-order NLTE kinetic model for radiating plasmas such as are found in the outer layers of stellar atmospheres. Starting from the most up-to-date set of ab-initio and experimental data, the…

Solar and Stellar Astrophysics · Physics 2017-04-12 A. Munafo , N. Mansour , M. Panesi

We propose in this work a Monte Carlo method for three dimensional scalar radiative transfer equations with non-integrable, space-dependent scattering kernels. Such kernels typically account for long-range statistical features, and arise…

Numerical Analysis · Mathematics 2023-07-19 Christophe Gomez , Olivier Pinaud

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

The theory of radiative transfer provides the link between the physical conditions in an astrophysical object and the observable radiation which it emits. Thus accurately modelling radiative transfer is often a necessary part of testing…

Solar and Stellar Astrophysics · Physics 2009-11-10 S. A. Sim , M. Kromer , F. K. Roepke , E. I. Sorokina , S. I. Blinnikov , D. Kasen , W. Hillebrandt

Atom localization enables a high-precision imaging of the atomic position, which has provided vast applications in fundamental and applied science. In the present work, we propose a scheme for realizing two-dimensional off-axis atom…

Quantum Physics · Physics 2022-06-23 Ning Jia , Xing-Dong Zhao , Wen-Rong Qi , Jing Qian

Shaping the light emission characteristics of laser systems is of great importance in various areas of science and technology. In a typical lasing arrangement, the spatial profile of the mode tends to remain self-similar throughout the…

Monte Carlo radiative transfer, which has been demonstrated as a successful algorithm for modeling radiation transport through the astrophysical medium, relies on sampling of scattering phase functions. We review several classic sampling…

Computational Physics · Physics 2019-09-18 Jianing Zhang

In biochemically reactive systems with small copy numbers of one or more reactant molecules, the dynamics is dominated by stochastic effects. To approximate those systems, discrete state-space and stochastic simulation approaches have been…

Numerical Analysis · Mathematics 2020-07-13 Chiheb Ben Hammouda , Alvaro Moraes , Raul Tempone

We present a novel generalization of the two-stream method of radiative transfer, which allows for the accurate treatment of radiative transfer in the presence of strong infrared scattering by aerosols. We prove that this generalization…

Earth and Planetary Astrophysics · Physics 2017-10-04 Kevin Heng , Daniel Kitzmann

We consider an alternative to the Monte Carlo method for dust continuous radiative transfer simulations: the Quasi-Monte Carlo method. We briefly discuss what it is, its history, and possible implementations. We compare the Monte Carlo…

Solar and Stellar Astrophysics · Physics 2024-06-25 S. G. Shulman

In wireless ad hoc networks, distributed nodes can collaboratively form an antenna array for long-distance communications to achieve high energy efficiency. In recent work, Ochiai, et al., have shown that such collaborative beamforming can…

Information Theory · Computer Science 2007-07-13 Athina P. Petropulu , Lun Dong , H. Vincent Poor

Sampling from multimodal distributions is a challenging task in scientific computing. When a distribution has an exact symmetry between the modes, direct jumps among them can accelerate the samplings significantly. However, the…

Numerical Analysis · Mathematics 2024-01-05 Lexing Ying