English
Related papers

Related papers: A pseudospectral method for solution of the radiat…

200 papers

We present a geometric multigrid solver for the M1 model of radiative transfer without source terms. In radiative hydrodynamics applications, the radiative transfer needs to be solved implicitly because of the fast propagation speed of…

Numerical Analysis · Mathematics 2022-09-28 Hélène Bloch , Pascal Tremblin , Matthias González , Edouard Audit

A two-point ray-tracing technique for 3D smoothly heterogeneous, weakly transversely-isotropic media is based on Fermat's principle and takes advantage of global Chebyshev approximation of both the model and curved rays. This approximation…

Geophysics · Physics 2019-02-07 Vladimir Grechka , George A. McMechan

Three-dimensional neutron transport calculations using the Method of Characteristics (MOC) are highly regarded for their exceptional computational efficiency, precision, and stability. Nevertheless, when dealing with extensive-scale…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-03-25 Faguo Zhou , Shunde Li , Rong Xue , Lingkun Bu , Ningming Nie , Peng Shi , Jue Wang , Yun Hu , Zongguo Wang , Yangang Wang , Qinmeng Yang , Miao Yu

Anomalous diffusion phenomena are ubiquitous in complex media, such as biological tissues. A wide class of sub-diffusive phenomena phenomena is described by the time-fractional diffusion equation. The paper investigates the case of…

Classical Analysis and ODEs · Mathematics 2018-10-02 Dimiter Prodanov

General relativistic radiation hydrodynamics simulations are necessary to accurately model a number of astrophysical systems involving black holes and neutron stars. Photon transport plays a crucial role in radiatively dominated accretion…

High Energy Astrophysical Phenomena · Physics 2018-01-31 Francois Foucart

Anisotropic light transport is extremely common among scattering materials, yet a comprehensive picture of how macroscopic diffusion is determined by microscopic tensor scattering coefficients is not fully established yet. In this work, we…

Computer simulations of photon transport through an absorbing and/or scattering medium form an important research tool in astrophysics. Nearly all software codes performing such simulations for three-dimensional geometries employ the Monte…

Instrumentation and Methods for Astrophysics · Physics 2018-07-25 Peter Camps , Maarten Baes

The 3D Gaussian splatting method has drawn a lot of attention, thanks to its high performance in training and high quality of the rendered image. However, it uses anisotropic Gaussian kernels to represent the scene. Although such…

Computer Vision and Pattern Recognition · Computer Science 2024-03-22 Yuanhao Gong , Lantao Yu , Guanghui Yue

In geophysics, wave propagation in elastic media is a crucial subject. In this context, seismology has made significant progress as a result of numerous advances, among these stands out the advancement of numerical methods such as the…

Physics Education · Physics 2021-08-02 Gabriela Landinez , Santiago Rueda , Fabio D. Lora-Clavijo

The possibility of using time-resolved vibronic spectroscopy for spectral analysis of mixtures of chemical compounds with similar optical properties, when traditional methods are inefficient, is demonstrated by using the method of computer…

Chemical Physics · Physics 2007-05-23 S. A. Astakhov , V. I. Baranov

Imaging the propagation of light in time and space is crucial in optics, notably for the study of complex media. We here demonstrate the passive measurement of time-dependent Green's functions between every point at the surface of a…

Traditional Monte Carlo methods for particle transport utilize source iteration to express the solution, the flux density, of the transport equation as a Neumann series. Our contribution is to show that the particle paths simulated within…

Probability · Mathematics 2024-07-03 J. Darby Smith , Rich Lehoucq , Brian Franke

The polyhedral homotopy method of Huber and Sturmfels is a particularly efficient and robust numerical method for solving system of (Laurent) polynomial equations. A central component in an implementation of this method is an efficient and…

Algebraic Geometry · Mathematics 2021-11-30 Tianran Chen

In order to model astrophysical environments characterized by radial stratification, such as supernova remnants or expanding superbubbles; correctly understanding the transport of non-thermal particles in astrophysical plasmas is essential.…

High Energy Astrophysical Phenomena · Physics 2026-04-22 José María García-Morillo , Stefano Menchiari , Rubén López-Coto

In this work, we extend the solid harmonics derivation, which was used by Ackroyd et al to derive the steady-state SP$_N$ equations, to transient problems. The derivation expands the angular flux in ordinary surface harmonics but uses…

Computational Physics · Physics 2017-01-03 Can Pu , Ryan G. McClarren

Ray tracing is a technique for generating an image by tracing the path of light through pixels in an image plane and simulating the effects of high-quality global illumination at a heavy computational cost. Because of the high computation…

Graphics · Computer Science 2015-04-14 Yutong Qin , Jianbiao Lin , Xiang Huang

We discuss a numerical scheme to solve the continuum Kardar-Parisi-Zhang equation in generic spatial dimensions. It is based on a momentum-space discretization of the continuum equation and on a pseudo-spectral approximation of the…

Statistical Mechanics · Physics 2009-11-07 Lorenzo Giada , Achille Giacometti , Maurice Rossi

Spectral methods based on integral transforms may be efficiently used to solve differential equations in some special cases. This paper considers a different approach in which algorithms are proposed to calculate integral Laguerre transform…

Numerical Analysis · Mathematics 2022-01-12 Andrew V. Terekhov

We simulate convection near the solar surface, where the continuum optical depth is of order unity. Hence, to determine the radiative heating and cooling in the energy conservation equation, we must solve the radiative transfer equation…

Astrophysics · Physics 2007-05-23 Robert Stein , Aake Nordlund

Astrophysical plasmas are subject to a tight connection between magnetic fields and the diffusion of particles, which leads to an anisotropic transport of energy. Under the fluid assumption, this effect can be reduced to an…

Astrophysics of Galaxies · Physics 2016-01-13 Yohan Dubois , Benoît Commerçon