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We present a new radiative transfer method (SPH-M1RT) that is coupled dynamically with smoothed particle hydrodynamics (SPH). We implement it in the (task-based parallel) SWIFT galaxy simulation code but it can be straightforwardly…

Instrumentation and Methods for Astrophysics · Physics 2021-07-06 T. K. Chan , Tom Theuns , Richard Bower , Carlos Frenk

While new light sources allow for unprecedented resolution in experiments with X-rays, a theoretical understanding of the scattering cross-section is lacking. In the particular case of strongly correlated electron systems, numerical…

Strongly Correlated Electrons · Physics 2023-05-29 Krissia Zawadzki , Alberto Nocera , Adrian E. Feiguin

Light transfer in gradient-index media generally follows curved ray trajectories, which will cause light beam to converge or diverge during transfer and induce the rotation of polarization ellipse even when the medium is transparent.…

Optics · Physics 2014-12-16 J. M. Zhao , J. Y. Tan , L. H. Liu

Ray-tracing (RT) has become central to site-specific electromagnetic propagation modeling in dynamic complex environments. Yet its computational burden grows sharply as high-fidelity digital twins of these environments scale to millions of…

Signal Processing · Electrical Eng. & Systems 2026-05-19 Giacomo Melloni , Enrico M. Vitucci , Vittorio Degli Esposti , Samuel Berweger , Jack Chuang , Camillo Gentile , Nada Golmie

We use the alternating direction method to simulate implicit dynamics. ur spatial discretization uses isogeometric analysis. Namely, we simulate a (hyperbolic) wave propagation problem in which we use tensor-product B-splines in space and…

Numerical Analysis · Mathematics 2019-11-20 Marcin Los , Pouria Behnoudfar , Maciej Paszynski , Victor Manuel Calo

Asymptotic radiative transfer (ART), like diffusion theory, assumes the angular intensity distribution incident at a boundary is identical with that in the depth of the scattering medium. However, the asymptotic intensity profile and…

Optics · Physics 2019-05-06 Adrian Selden

A formalism is introduced for the non-perturbative, purely numerical, solution of the reduced Rayleigh equation for the scattering of light from two-dimensional penetrable rough surfaces. As an example, we apply this formalism to study the…

Optics · Physics 2012-05-03 Tor Nordam , Paul Anton Letnes , Ingve Simonsen

Memory-effect-based methods have been demonstrated to be feasible to observe hidden objects through thin scattering layers, even from a single-shot speckle pattern. However, most of the existing methods are performed with narrowband…

Image and Video Processing · Electrical Eng. & Systems 2018-09-20 Tengfei Wu , Chengfei Guo , Xiaopeng Shao

In theory, active control could be used to reduce the unwanted noise reflections from surfaces such as a submarine hull or the walls of an anechoic room. In the recent years, a real-time algorithm has been developed to this effect at the…

Classical Physics · Physics 2009-11-25 Emmanuel Friot , Alexandre Gintz

We present a novel approximation method that can predict the number of solitons asymptotically appearing under arbitrary rapidly decreasing initial wave packets. The number of solitons can be estimated without integration of the original…

Exactly Solvable and Integrable Systems · Physics 2017-06-07 Hironobu Fujishima , Tetsu Yajima

An implicit method for radiative transfer in SPH is described. The diffusion approximation is used, and the hydrodynamic calculations are performed by a fully three--dimensional SPH code. Instead of the energy equation of state for an ideal…

Astrophysics · Physics 2009-11-11 Serge Viau , Pierre Bastien , Seung-Hoon Cha

In this study, we investigate atom--dimer scattering within the framework of the hyperspherical method. The coupled channel Schr\"odinger equation is solved using the R-matrix propagation technique combined with the smooth variable…

Atomic Physics · Physics 2022-10-19 Cai-Yun Zhao , Yi Zhang , Hui-Li Han , Ting-Yun Shi

In this paper, we propose Fourier pseudospectral methods to solve the variable-order space fractional wave equation and develop an accelerated matrix-free approach for its effective implementation. In constant-order cases, our methods can…

Numerical Analysis · Mathematics 2024-02-06 Yanzhi Zhang , Xiaofei Zhao , Shiping Zhou

We study the convergence of the Left-Right splitting method (equivalent in key respects to the Method of Multiple Ordered Interactions and Forward-Backward method) for wave scattering by rough surfaces. This is an operator series method…

Numerical Analysis · Mathematics 2025-08-19 Paul E Parbone , Mark Spivack , Orsola Rath Spivack

This work proposes a universal and adaptive second-order method for minimizing second-order smooth, convex functions. Our algorithm achieves $O(\sigma / \sqrt{T})$ convergence when the oracle feedback is stochastic with variance $\sigma^2$,…

Optimization and Control · Mathematics 2022-12-13 Kimon Antonakopoulos , Ali Kavis , Volkan Cevher

While scattered light conveys most of the information we perceive, scattering may also distort that information before it reaches our detectors. The problem is acute in many applications, such as in high-resolution microscopy of biological…

An efficient and accurate image reconstruction algorithm for ultrasound tomography (UST) is described and demonstrated, which can recover accurate sound speed distribution from acoustic time series measurements made in soft tissue. The…

Numerical Analysis · Mathematics 2021-11-17 Ashkan Javaherian , Ben Cox

Here, we present a numerical post-processing method for removing the effect of anti-symmetric residual aberrations in high-resolution transmission electron microscopy (HRTEM) images of weakly scattering 2D-objects. The method is based on…

Materials Science · Physics 2015-01-19 Ossi Lehtinen , Dorin Geiger , Zhongbo Lee , Michale B. Whitwick , Ming-Wei Chen , Andras Kis , Ute Kaiser

Radiative transfer coupled with highly realistic simulations of the solar atmosphere is routinely used to infer the physical properties underlying solar observations. Due to its computational efficiency, the method of short-characteristics…

Solar and Stellar Astrophysics · Physics 2018-04-17 Courtney L. Peck , Serena Criscuoli , Mark P. Rast

Photon transport through a diffusing slab can be described by the radiative transfer equation (RTE). When the slab is highly scattering and weakly absorbing, the RTE simplifies to the diffusion equation. In this paper, an inverse diffusion…