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Related papers: Accurate Diffusion Coefficients for Dense White Dw…

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This paper proposes DiffPF, a differentiable particle filter that leverages diffusion models for state estimation in dynamic systems. Unlike conventional differentiable particle filters, which require importance weighting and typically rely…

Robotics · Computer Science 2026-01-13 Ziyu Wan , Lin Zhao

We present a detailed model atmosphere analysis of hot white dwarfs in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. Our sample includes 19,321 unique targets with $G_{\rm BP}-G_{\rm RP}\leq0$. We use the DESI spectra…

Convective overshooting in super asymptotic giant branch stars has been suggested to lead to the formation of hybrid white dwarfs with carbon-oxygen cores and oxygen-neon mantles. As the white dwarf cools, this core-mantle configuration…

Solar and Stellar Astrophysics · Physics 2019-05-01 Josiah Schwab , Pascale Garaud

Originating from the diffusion phenomenon in physics that describes particle movement, the diffusion generative models inherit the characteristics of stochastic random walk in the data space along the denoising trajectory. However, the…

Computer Vision and Pattern Recognition · Computer Science 2024-03-19 Ruoyu Wang , Yongqi Yang , Zhihao Qian , Ye Zhu , Yu Wu

In this paper we discuss the results of some Molecular Dynamics simulations of a magnetized One Component Plasma, targeted to estimate the diffusion coefficient $D_{\perp}$ in the plane orthogonal to the magnetic field lines. We find that…

Plasma Physics · Physics 2022-10-21 Lorenzo Valvo , Andrea Carati

Turbulent transport of chemical elements in radiative zones of stars is considered in current stellar evolution codes thanks to phenomenologically derived diffusion coefficients. Recent local numerical simulations (Prat & Ligni\`eres 2013,…

Solar and Stellar Astrophysics · Physics 2014-07-02 Vincent Prat , François Lignières

The recent, impressive advances in algorithmic generation of high-fidelity image, audio, and video are largely due to great successes in score-based diffusion models. A key implementing step is score matching, that is, the estimation of the…

Machine Learning · Statistics 2024-09-12 Zehao Dou , Subhodh Kotekal , Zhehao Xu , Harrison H. Zhou

The B/C ratio is used in cosmic-ray physics to constrain the transport parameters. However, from the same set of data, the various published values show a puzzling large scatter of these parameters. We investigate the impact of using…

High Energy Astrophysical Phenomena · Physics 2010-07-08 D. Maurin , A. Putze , L. Derome

We investigate stellar metallicity distribution functions (MDFs), including Fe and ${\alpha}$-element abundances, in dwarf galaxies from the Feedback in Realistic Environments (FIRE) project. We examine both isolated dwarf galaxies and…

Thanks to their continuous cooling and relative simplicity, white dwarf stars are routinely used to measure the ages of stellar populations. The usefulness of white dwarfs as cosmochronometers depends on the availability of accurate cooling…

Solar and Stellar Astrophysics · Physics 2020-08-19 Simon Blouin , Nathaniel R. Shaffer , Didier Saumon , Charles E. Starrett

In a convergence of machine learning and biology, we reveal that diffusion models are evolutionary algorithms. By considering evolution as a denoising process and reversed evolution as diffusion, we mathematically demonstrate that diffusion…

Neural and Evolutionary Computing · Computer Science 2026-05-12 Yanbo Zhang , Benedikt Hartl , Hananel Hazan , Michael Levin

Over 1500 DBZ or DZ white dwarfs (WDs) have been observed so far, and polluted atmospheres with metal elements have been found among these WDs. The surface heavy element abundances of known DBZ or DZ WDs show an evolutionary sequence. By…

Solar and Stellar Astrophysics · Physics 2021-10-13 Chunhua Zhu , Helei Liu , Zhaojun Wang , Guoliang Lv

A detailed record of the physical processes that operate during post-main-sequence evolution is contained in the internal chemical structure of white dwarfs. Global pulsations allow us to probe the stellar interior through asteroseismology,…

Astrophysics · Physics 2007-05-23 Travis S. Metcalfe

White Dwarfs (WDs), the final evolutionary stage of most stars, are frequently modeled considering only a dense plasma matter. However, their potential interaction with dark matter (DM), especially in galactic halos where DM is expected to…

Solar and Stellar Astrophysics · Physics 2025-11-07 Sílvia P. Nunes , José D. V. Arbañil , Juan M. Z. Pretel , Sérgio B. Duarte

We propose a general methodology for calculating the self-diffusion tensor from molecular dynamics for a liquid with a liquid-gas or liquid-solid interface. The standard method used in bulk fluids, based on computing the mean square…

Chemical Physics · Physics 2007-05-23 Pu Liu , Edward Harder , B. J. Berne

Self-diffusion and interdiffusion coefficients of binary ionic mixtures are evaluated using the Effective Potential Theory (EPT), and the predictions are compared with the results of molecular dynamics simulations. We find that EPT agrees…

Plasma Physics · Physics 2017-02-01 Nathaniel R. Shaffer , Scott D. Baalrud , Jérôme Daligault

We introduce the state-of-the-art deep learning Denoising Diffusion Probabilistic Model (DDPM) as a method to infer the volume or number density of giant molecular clouds (GMCs) from projected mass surface density maps. We adopt…

Astrophysics of Galaxies · Physics 2023-06-28 Duo Xu , Jonathan C. Tan , Chia-Jung Hsu , Ye Zhu

It was suggested in the literature that the self-diffusion coefficient of simple fluids can be approximated as a ratio of the squared thermal velocity of the atoms to the "fluid Einstein frequency," which can thus serve as a rough estimate…

Soft Condensed Matter · Physics 2018-04-10 Sergey Khrapak , Boris Klumov , Lenaic Couedel

The diffusion of particles trapped in long narrow channels occurs predominantly in one dimension. Here, molecular dynamics simulation is used to study the inertial dynamics of two-dimensional hard disks, confined to long, narrow,…

Soft Condensed Matter · Physics 2020-02-05 Mahdi Zarif , Richard K. Bowles

Ionic conductivity is a critical property of solid ionic conductors, directly influencing the performance of energy storage devices such as batteries. However, accurately calculating ionic conductivity or diffusion coefficient remains…

Materials Science · Physics 2025-03-07 Yuxiang Gao , Xiaodong Cao , Zhicheng Zhong
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