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Related papers: Radiative transfer on hierarchial grids

200 papers

Constraints on the density and thermal 3D structure of the dense molecular cloud core Rho Oph D are derived from a detailed 3D radiative transfer modeling. Two ISOCAM images at 7 and 15 micron are fitted simultaneously by representing the…

Astrophysics · Physics 2009-11-10 J. Steinacker , A. Bacmann , Th. Henning , R. Klessen , M. Stickel

We propose a seamless multiscale method which approximates the macroscopic behavior of the passive advection-diffusion equations with steady incompressible velocity fields with multi-spatial scales. The method uses decompositions of the…

Numerical Analysis · Mathematics 2016-06-22 Yoonsang Lee , Bjorn Engquist

State-of-the-art JWST observations are unveiling unprecedented views into the atmospheres of substellar objects in the infrared, further highlighting the importance of clouds. Current forward models struggle to fit the silicate clouds…

We propose a method of simulation that is based on the averaging of formal solutions of the transfer equation by taking the integral by the Monte Carlo method. This method is used to compute two models, which correspond to the limiting…

Astrophysics · Physics 2007-05-23 Maxim A. Voronkov

Radiative transfer describes the propagation of electromagnetic radiation through an interacting medium. This process is often simulated by the use of the Monte Carlo method, which involves the probabilistic determination and tracking of…

Instrumentation and Methods for Astrophysics · Physics 2020-03-31 A. Krieger , S. Wolf

We introduce a new, high-throughput, synchronous, distributed, data-parallel, stochastic-gradient-descent learning algorithm. This algorithm uses amortized inference in a compute-cluster-specific, deep, generative, dynamical model to…

Distributed, Parallel, and Cluster Computing · Computer Science 2018-03-14 Michael Teng , Frank Wood

We introduce a fast algorithm for computing sparse Fourier transforms supported on smooth curves or surfaces. This problem appear naturally in several important problems in wave scattering and reflection seismology. The main observation is…

Numerical Analysis · Mathematics 2008-01-11 Lexing Ying

We present a novel numerical implementation of radiative transfer in the cosmological smoothed particle hydrodynamics (SPH) simulation code {\small GADGET}. It is based on a fast, robust and photon-conserving integration scheme where the…

Astrophysics · Physics 2009-06-23 M. Petkova , V. Springel

We introduce and test a new and highly efficient method for treating the thermal and radiative effects influencing the energy equation in SPH simulations of star formation. The method uses the density, temperature and gravitational…

Astrophysics · Physics 2009-11-13 D. Stamatellos , A. P. Whitworth , T. Bisbas , S. Goodwin

Context: Thermal conductivity provides important contributions to the energy evolution of the upper solar atmosphere, behaving as a non-linear concentration-dependent diffusion equation. Recently, different methods have been offered as…

Solar and Stellar Astrophysics · Physics 2024-12-11 George Cherry , Boris Gudiksen , Mikolaj Szydlarski

By radiation transfer models with a realistic power spectra of the projected density distributions, we show that the optical properties of grains are poorly constrained by observations of reflection nebulae. The ISM is known to be…

Astrophysics · Physics 2009-11-07 John S. Mathis , Barbara A. Whitney , Kenneth Wood

The scattering matrix, which quantifies the optical reflection and transmission of a photonic structure, is pivotal for understanding the performance of the structure. In many photonic design tasks, it is also desired to know how the…

Optics · Physics 2020-12-30 Ziwei Zhu , Changxi Zheng

A new means of incorporating radiative transfer into smoothed particle hydrodynamics (SPH) is introduced, which builds on the success of two previous methods - the polytropic cooling approximation as devised by Stamatellos et al (2007), and…

Astrophysics · Physics 2009-11-13 Duncan Forgan , Ken Rice , Dimitris Stamatellos , Anthony Whitworth

Diffusion models have recently achieved remarkable performance in image super-resolution (SR), but their high computational cost limits practical deployment in remote sensing applications. To address this issue, we propose SlimDiffSR, a…

Computer Vision and Pattern Recognition · Computer Science 2026-05-19 Ce Wang , Zhenyu Hu , Wanjie Sun

This work presents an efficient numerical method based on spectral expansions for simulation of heat and moisture diffusive transfers through multilayered porous materials. Traditionally, by using the finite-difference approach, the problem…

Computational Engineering, Finance, and Science · Computer Science 2020-02-20 Suelen Gasparin , Denys Dutykh , Nathan Mendes

The inference latency of diffusion models remains a critical barrier to their real-time application. While trajectory-based and distribution-based step distillation methods offer solutions, they present a fundamental trade-off.…

Computer Vision and Pattern Recognition · Computer Science 2025-11-13 Hanbo Cheng , Peng Wang , Kaixiang Lei , Qi Li , Zhen Zou , Pengfei Hu , Jun Du

Calculation of near-neighbor interactions among high dimensional, irregularly distributed data points is a fundamental task to many graph-based or kernel-based machine learning algorithms and applications. Such calculations, involving…

We present an efficient algorithm designed for and capable of detecting elongated, thin features such as lines and curves in astronomical images, and its application to the automatic detection of gravitational arcs. The algorithm is…

Astrophysics · Physics 2009-11-11 Gregor Seidel , Matthias Bartelmann

Advanced diffusion models (DMs) perform impressively in image super-resolution (SR), but the high memory and computational costs hinder their deployment. Binarization, an ultra-compression algorithm, offers the potential for effectively…

Computer Vision and Pattern Recognition · Computer Science 2024-11-01 Zheng Chen , Haotong Qin , Yong Guo , Xiongfei Su , Xin Yuan , Linghe Kong , Yulun Zhang

In radio astronomy, accurate calibration is of crucial importance for the new generation of radio interferometers. More specifically, because of the potential presence of outliers which affect the measured data, robustness needs to be…

Instrumentation and Methods for Astrophysics · Physics 2018-08-01 Virginie Ollier , Mohammed Nabil El Korso , André Ferrari , Rémy Boyer , Pascal Larzabal