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Most of the physical information about astrophysical objects is obtained via the analysis of their electromagnetic spectra. Observed data coupled with radiation transfer models in physical conditions representative of stars, planets,…

Solar and Stellar Astrophysics · Physics 2026-05-29 Maria Bergemann , Richard Hoppe

Resonance lines encode rich information about astrophysical sources and their environments, yet fully analytic treatments of multi-line radiative transfer remain almost entirely unexplored. We present exact, closed-form solutions for…

Astrophysics of Galaxies · Physics 2026-02-18 Ethan Stace , Aaron Smith , Kevin Lorinc , Olof Nebrin

An iterative method is derived for image reconstruction. Among other attributes, this method allows constraints unrelated to the radiation measurements to be incorporated into the reconstructed image. A comparison is made with the widely…

Computational Physics · Physics 2011-01-06 Clinton DeW. Van Siclen

Accurate reconstruction of 2D and 3D isotope densities is a desired capability with great potential impact in applications such as evaluation and development of next-generation nuclear fuels. Neutron time-of-flight (TOF) resonance imaging…

Image and Video Processing · Electrical Eng. & Systems 2023-09-13 Thilo Balke , Alexander M. Long , Sven C. Vogel , Brendt Wohlberg , Charles A. Bouman

The theoretical formalism of inclusive lepton-nucleus scattering in the two-nucleon emission channel is discussed in the context of a simplified approach, the modified convolution approximation. This allows one to write the 2p2h responses…

Nuclear Theory · Physics 2018-01-17 I. Ruiz Simo , J. E. Amaro , M. B. Barbaro , J. A. Caballero , G. D. Megias , T. W. Donnelly

We use the well-known observation that the solutions of Jacobi's differential equation can be represented via non-oscillatory phase and amplitude functions to develop a fast algorithm for computing multi-dimensional Jacobi polynomial…

Numerical Analysis · Mathematics 2019-09-13 James Bremer , Qiyuan Pang , Haizhao Yang

In this paper, we propose the neural Born iterative method (NeuralBIM) for solving 2D inverse scattering problems (ISPs) by drawing on the scheme of physics-informed supervised residual learning (PhiSRL) to emulate the computing process of…

Computational Physics · Physics 2023-11-22 Tao Shan , Zhichao Lin , Xiaoqian Song , Maokun Li , Fan Yang , Zhensheng Xu

We address the problem of decomposing an image into albedo and shading. We propose the Fast Fourier Intrinsic Network, FFI-Net in short, that operates in the spectral domain, splitting the input into several spectral bands. Weights in…

Computer Vision and Pattern Recognition · Computer Science 2020-11-10 Yanlin Qian , Miaojing Shi , Joni-Kristian Kämäräinen , Jiri Matas

Large Language Models (LLMs) have demonstrated remarkable performance across a wide range of tasks, but their deployment is often constrained by substantial memory footprints and computational costs. While prior work has achieved…

Machine Learning · Computer Science 2026-02-04 Jiangyong Yu , Xiaomeng Han , Xing Hu , Chen Xu , Zhe Jiang , Dawei Yang

The behavior of non-local thermal-equilibrium (NLTE) plasmas plays a central role in many fields of modern-day physics, such as laser-produced plasmas, astrophysics, inertial or magnetic confinement fusion devices, or X-ray sources. The…

Plasma Physics · Physics 2015-05-13 M. Poirier , F. de Gaufridy de Dortan

Modern Flash X-ray diffraction Imaging (FXI) acquires diffraction signals from single biomolecules at a high repetition rate from X-ray Free Electron Lasers (XFELs), easily obtaining millions of 2D diffraction patterns from a single…

Image and Video Processing · Electrical Eng. & Systems 2020-10-28 Jing Liu , Stefan Engblom , Carl Nettelblad

We present an integral-based technique (IBT) algorithm to accelerate supernova (SN) radiative transfer calculations. The algorithm utilizes ``integral packets'', which are calculated by the path integral of the Monte-Carlo energy packets,…

High Energy Astrophysical Phenomena · Physics 2024-09-13 Xingzhuo Chen , Lifan Wang , Daniel Kasen

In this paper, we study the impact of computational complexity on the throughput limits of the {\color{black}fast Fourier transform (FFT)} algorithm for {\color{black}orthogonal frequency division multiplexing(OFDM)} waveforms. Based on the…

Signal Processing · Electrical Eng. & Systems 2022-09-30 Saulo Queiroz , João P. Vilela , Edmundo Monteiro

We propose a novel concept of dual and integrated latent topologies (DITTO in short) for implicit 3D reconstruction from noisy and sparse point clouds. Most existing methods predominantly focus on single latent type, such as point or grid…

Computer Vision and Pattern Recognition · Computer Science 2024-06-26 Jaehyeok Shim , Kyungdon Joo

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

The inverse problem we consider is to reconstruct the location and shape of buried obstacles in the lower half-space of an unbounded two-layered medium in two dimensions from phaseless far-field data. A main difficulty of this problem is…

Numerical Analysis · Mathematics 2021-05-26 Long Li , Jiansheng Yang , Bo Zhang , Haiwen Zhang

A two-step shape reconstruction method for diffuse optical tomography (DOT) is presented which uses adjoint fields and level sets. The propagation of near-infrared photons in tissue is modeled by the time-dependent linear transport…

Numerical Analysis · Mathematics 2025-10-20 Oliver Dorn

We present a new approach for solving high-order thermal radiative transfer (TRT) using the Variable Eddington Factor (VEF) method (also known as quasidiffusion). Our approach leverages the VEF equations, which consist of the first and…

Computational Physics · Physics 2021-04-19 Ben C. Yee , Samuel S. Olivier , Ben S. Southworth , Milan Holec , Terry S. Haut

We present a new two-snapshot structured light illumination (SLI) reconstruction algorithm for fast image acquisition. The new algorithm, which only requires two mutually {\pi} phase-shifted raw structured images, is implemented on a…

Optics · Physics 2017-10-25 Yunlong Meng , Wei Lin , Chenglin Li , Shih-chi Chen

Generative models based on flow matching have attracted significant attention for their simplicity and superior performance in high-resolution image synthesis. By leveraging the instantaneous change-of-variables formula, one can directly…

Computer Vision and Pattern Recognition · Computer Science 2025-01-06 Yasi Zhang , Peiyu Yu , Yaxuan Zhu , Yingshan Chang , Feng Gao , Ying Nian Wu , Oscar Leong