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Related papers: Nyx-RT: Adaptive Ray Tracing in the Nyx Hydrodynam…

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A common task in astronomical research is to estimate the physical parameters (temperature, mass, density etc.) of a gas by using observed line emission. This often requires a calculation of how the radiation propagates via emission and…

Instrumentation and Methods for Astrophysics · Physics 2026-03-03 Gianni Cataldi

We describe the first parallel implementation of an adaptive particle-particle, particle-mesh code with smoothed particle hydrodynamics. Parallelisation of the serial code, ``Hydra'', is achieved by using CRAFT, a Cray proprietary language…

Astrophysics · Physics 2009-10-30 F. R. Pearce , H. M. P. Couchman

We have developed non-sequential ray-tracing software which is aimed to be widely used, along with air- shower simulations, in the design of optical systems for cosmic-ray experiments. The code is based on the ROOT geometry library to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Akira Okumura , Masaaki Hayashida , Hideaki Katagiri , Takayuki Saito , Vladimir Vassiliev

Image-based, patient-specific modelling of hemodynamics can improve diagnostic capabilities and provide complementary insights to better understand the hemodynamic treatment outcomes. However, computational fluid dynamics simulations remain…

Numerical Analysis · Mathematics 2025-02-18 Francesco Romor , Felipe Galarce , Jan Brüning , Leonid Goubergrits , Alfonso Caiazzo

Accelerating neural radiance fields training is of substantial practical value, as the ray sampling strategy profoundly impacts network convergence. More efficient ray sampling can thus directly enhance existing NeRF models' training…

Computer Vision and Pattern Recognition · Computer Science 2023-08-31 Shilei Sun , Ming Liu , Zhongyi Fan , Yuxue Liu , Chengwei Lv , Liquan Dong , Lingqin Kong

Radar is a critical perception modality in autonomous driving systems due to its all-weather characteristics and ability to measure range and Doppler velocity. However, the sheer volume of high-dimensional raw radar data saturates the…

Computer Vision and Pattern Recognition · Computer Science 2026-04-03 Jinho Park , Se Young Chun , Mingoo Seok

We introduce GRay, a massively parallel integrator designed to trace the trajectories of billions of photons in a curved spacetime. This GPU-based integrator employs the stream processing paradigm, is implemented in CUDA C/C++, and runs on…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Chi-kwan Chan , Dimitrios Psaltis , Feryal Ozel

Solving the shallow water equations efficiently is critical to the study of natural hazards induced by tsunami and storm surge, since it provides more response time in an early warning system and allows more runs to be done for…

Computational Physics · Physics 2019-01-23 Xinsheng Qin , Randall LeVeque , Michael Motley

Methods to solve the relativistic hydrodynamic equations are a key computational kernel in a large number of astrophysics simulations and are crucial to understanding the electromagnetic signals that originate from the merger of…

Instrumentation and Methods for Astrophysics · Physics 2015-12-02 Jackson DeBuhr , Bo Zhang , Matthew Anderson , David Neilsen , Eric W. Hirschmann

Mixed-frame formulations of radiation-hydrodynamics (RHD), where the radiation quantities are computed in an inertial frame but matter quantities are in a comoving frame, are advantageous because they admit algorithms that conserve energy…

Astrophysics of Galaxies · Physics 2024-11-25 Chong-Chong He , Benjamin D. Wibking , Mark R. Krumholz

Radiative transfer is a fundamental process in astrophysics, essential for both interpreting observations and modeling thermal and dynamical feedback in simulations via ionizing radiation and photon pressure. However, numerically solving…

Instrumentation and Methods for Astrophysics · Physics 2025-11-12 Rune Rost , Lorenzo Branca , Tobias Buck

We study the statistics of the Lyman-$\alpha$ forest in a flat LCDM cosmology with the N-body + Eulerian hydrodynamics code Nyx. We produce a suite of simulations, covering the observationally relevant redshift range $2 \leq z \leq 4$. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-24 Zarija Lukić , Casey Stark , Peter Nugent , Martin White , Avery Meiksin , Ann Almgren

Non-LTE radiative transfer is a key tool for modern astrophysics: it is the means by which many key synthetic observables are produced, thus connecting simulations and observations. Radiative transfer models also inform our understanding of…

Solar and Stellar Astrophysics · Physics 2025-11-12 Christopher M. J. Osborne , Alexander Sannikov

High-performance implementations of $k$-Nearest Neighbor Search ($k$NN) in low dimensions use tree-based data structures. Tree algorithms are hard to parallelize on GPUs due to their irregularity. However, newer Nvidia GPUs offer hardware…

Graphics · Computer Science 2024-04-23 Durga Mandarapu , Vani Nagarajan , Artem Pelenitsyn , Milind Kulkarni

Reconstructing neural radiance fields with explicit volumetric representations, demonstrated by Plenoxels, has shown remarkable advantages on training and rendering efficiency, while grid-based representations typically induce considerable…

Computer Vision and Pattern Recognition · Computer Science 2023-05-30 Lingzhi Li , Zhongshu Wang , Zhen Shen , Li Shen , Ping Tan

Aerodynamic shape optimization has many industrial applications. Existing methods, however, are so computationally demanding that typical engineering practices are to either simply try a limited number of hand-designed shapes or restrict…

Computational Engineering, Finance, and Science · Computer Science 2018-02-13 Pierre Baqué , Edoardo Remelli , François Fleuret , Pascal Fua

Recent progress in large-scale scene rendering has yielded Neural Radiance Fields (NeRF)-based models with an impressive ability to synthesize scenes across small objects and indoor scenes. Nevertheless, extending this idea to large-scale…

Computer Vision and Pattern Recognition · Computer Science 2024-05-13 Xiaohan Zhang , Yukui Qiu , Zhenyu Sun , Qi Liu

In this paper, the general procedure to solve the General Relativistic Hydrodynamical(GRH) equations with Adaptive-Mesh Refinement (AMR) is presented. In order to achieve, the GRH equations are written in the conservation form to exploit…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Orhan Donmez

In this paper we propose an accurate, and computationally efficient method for incorporating adaptive spatial resolution into weakly-compressible Smoothed Particle Hydrodynamics (SPH) schemes. Particles are adaptively split and merged in an…

Fluid Dynamics · Physics 2022-05-17 Abhinav Muta , Prabhu Ramachandran

EMMA is a cosmological simulation code aimed at investigating the reionization epoch. It handles simultaneously collisionless and gas dynamics, as well as radiative transfer physics using a moment-based description with the M1…

Instrumentation and Methods for Astrophysics · Physics 2015-10-07 Dominique Aubert , Nicolas Deparis , Pierre Ocvirk