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We discuss the problem of polarized radiative transfer in general relativity. We present a set of equations suitable for solving the problem numerically for the case of an arbitrary space-time metric, and show numerical solutions to example…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Pauli Pihajoki , Antti Rantala , Peter H. Johansson

Three-dimensional x-ray CT image reconstruction in baggage scanning in security applications is an important research field. The variety of materials to be reconstructed is broader than medical x-ray imaging. Presence of high attenuating…

Computer Vision and Pattern Recognition · Computer Science 2015-08-20 S. Degirmenci , Joseph A. O'Sullivan , David G. Politte

Fast Fourier transform algorithms are an arsenal of effective tools for solving various problems of analysis and high-speed processing of signals of various natures. Almost all of these algorithms are designed to process sequences of…

Data Structures and Algorithms · Computer Science 2025-04-11 Aleksandr Cariow

In this paper, we consider acoustic or electromagnetic scattering in two dimensions from an infinite three-layer medium with thousands of wavelength-size dielectric particles embedded in the middle layer. Such geometries are typical of…

Numerical Analysis · Mathematics 2015-06-22 Jun Lai , Motoki Kobayashi , Leslie Greengard

We present a parallel distributed-memory algorithm for large deformation diffeomorphic registration of volumetric images that produces large isochoric deformations (locally volume preserving). Image registration is a key technology in…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-12-25 Andreas Mang , Amir Gholami , George Biros

We develop a representation of reverse-time migration in terms of Fourier integral operators the canonical relations of which are graphs. Through the dyadic parabolic decomposition of phase space, we obtain the solution of the wave equation…

Numerical Analysis · Mathematics 2015-09-24 Fredrik Andersson , Maarten V. de Hoop , Herwig Wendt

To facilitate the study of black hole fueling, star formation, and feedback in galaxies, we outline a method for treating the radial forces on interstellar gas due to absorption of photons by dust grains. The method gives the correct…

Astrophysics of Galaxies · Physics 2015-06-04 G. S. Novak , J. P. Ostriker , L. Ciotti

In this paper, we derive a practical, general framework for creating adaptive iterative (linearization or splitting) algorithms to solve multi-physics problems. This means that, given an iterative method, we derive \textit{a posteriori}…

Numerical Analysis · Mathematics 2026-01-26 Jakob S. Stokke , Kundan Kumar , Florin A. Radu

Iterative processing is widely adopted nowadays in modern wireless receivers for advanced channel codes like turbo and LDPC codes. Extension of this principle with an additional iterative feedback loop to the demapping function has proven…

Information Theory · Computer Science 2015-06-04 Salim Haddad , Amer Baghdadi , Michel Jezequel

Radiative transfer is a notoriously difficult and computationally demanding problem. Yet, it is an indispensable ingredient in nearly all astrophysical and cosmological simulations. Choosing an appropriate discretization scheme is a crucial…

Instrumentation and Methods for Astrophysics · Physics 2020-12-01 Frederik De Ceuster , Jan Bolte , Ward Homan , Silke Maes , Jolien Malfait , Leen Decin , Jeremy Yates , Peter Boyle , James Hetherington

We consider the numerical approximation of boundary conditions in radiative transfer problems by a perfectly matched layer approach. The main idea is to extend the computational domain by an absorbing layer and to use an appropriate…

Numerical Analysis · Mathematics 2018-02-26 Herbert Egger , Matthias Schlottbom

This paper presents a large-scale parallel solver, specifically designed to tackle the challenges of solving high-dimensional and high-contrast linear systems in heat transfer topology optimization. The solver incorporates an interpolation…

Numerical Analysis · Mathematics 2025-01-14 Yingjie Zhou , Changqing Ye , Yucheng Liu , Shubin Fu , Eric T. Chung

The inverse radiative transfer problem finds broad applications in medical imaging, atmospheric science, astronomy, and many other areas. This problem intends to recover the optical properties, denoted as absorption and scattering…

Numerical Analysis · Mathematics 2017-08-08 Qin Li , Ruiwen Shu , Li Wang

We develop a new relativistic radiation hydrodynamics code based on the Monte-Carlo algorithm. In this code, we implement a new scheme to achieve the second-order accuracy in time in the limit of a large packet number for solving the…

High Energy Astrophysical Phenomena · Physics 2023-02-15 Kyohei Kawaguchi , Sho Fujibayashi , Masaru Shibata

Radiative transfer plays a major role in high-energy astrophysics. In multiple scenarios and in a broad range of energy scales, the coupling between matter and radiation is essential to understand the interplay between theory, observations…

High Energy Astrophysical Phenomena · Physics 2022-12-28 Jose López-Miralles , Jose María Martí , Manel Perucho

Radiance fields have gained tremendous success with applications ranging from novel view synthesis to geometry reconstruction, especially with the advent of Gaussian splatting. However, they sacrifice modeling of material reflective…

Graphics · Computer Science 2025-09-30 Kaiwen Jiang , Jia-Mu Sun , Zilu Li , Dan Wang , Tzu-Mao Li , Ravi Ramamoorthi

We present a new radiative transfer code for axi-symmetric stellar atmospheres and compare test results against 1D and 2D models with and without velocity fields. The code uses the short characteristic method with modifications to handle…

Astrophysics · Physics 2009-11-11 J. Zsargo , D. J. Hillier , L. N. Georgiev

Convolutional Neural Networks have been the backbone of recent rapid progress in Single-Image Super-Resolution. However, existing networks are very deep with many network parameters, thus having a large memory footprint and being…

Computer Vision and Pattern Recognition · Computer Science 2018-04-24 George Seif , Dimitrios Androutsos

Estimating accurate high-dimensional transformations remains very challenging, especially in a clinical setting. In this paper, we introduce a multiscale parameterization of deformations to enhance registration and atlas estimation in the…

Optimization and Control · Mathematics 2025-01-31 Fleur Gaudfernau , Eléonore Blondiaux , Stéphanie Allassonnière , Erwan Le Pennec

We propose a defiltering method of turbulent flow fields for Lagrangian particle tracking using machine learning techniques. Numerical simulation of Lagrangian particle tracking is commonly used in various fields. In general, practical…

Fluid Dynamics · Physics 2024-11-21 Tomoya Oura , Koji Fukagata