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Related papers: Accurate Diffusion Coefficients for Dense White Dw…

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In the framework of our extensive modeling study of the spectral evolution of white dwarfs, we present here a new set of detailed calculations of the transport of residual hydrogen in helium-rich white dwarfs. First, we investigate the…

Solar and Stellar Astrophysics · Physics 2023-03-29 A. Bédard , P. Bergeron , P. Brassard

The standard diffusion processes are known to be obtained as the limits of appropriate random walks. These prelimiting random walks can be quite different however. The diffusion coefficient can be made responsible for the size of jumps or…

Probability · Mathematics 2022-03-10 Vassili N. Kolokoltsov

A number of cool white dwarfs with metal traces, of spectral types DAZ, DBZ, and DZ have been found to exhibit infrared excess radiation due to circumstellar dust. The origin of this dust is possibly a tidally disrupted asteroid that formed…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. Koester

As a result of competing physical mechanisms, the atmospheric composition of white dwarfs changes throughout their evolution, a process known as spectral evolution. Because of the ambiguity of their atmospheric compositions and the…

Solar and Stellar Astrophysics · Physics 2019-06-19 Simon Blouin , Patrick Dufour , Christian Thibeault , Nicole F. Allard

The standard theory of pulsations deals with the frequencies and growth rates of infinitesimal perturbations in a stellar model. Modes which are calculated to be linearly driven should increase their amplitudes exponentially with time; the…

Solar and Stellar Astrophysics · Physics 2020-02-19 M. H. Montgomery , J. J. Hermes , D. E. Winget , B. H. Dunlap , K. J. Bell

A comprehensive study on the applications of denoising diffusion models for wireless systems is provided. The article highlights the capabilities of diffusion models in learning complicated signal distributions, modeling wireless channels,…

Information Theory · Computer Science 2025-12-10 Mehdi Letafati , Samad Ali , Matti Latva-aho

Diffusion theory is a central tool of modern population genetics, yielding simple expressions for fixation probabilities and other quantities that are not easily derived from the underlying Wright-Fisher model. Unfortunately, the textbook…

Populations and Evolution · Quantitative Biology 2022-12-19 Camila Bräutigam , Matteo Smerlak

Depending on their mechanism of self-propulsion, active particles can exhibit a time-dependent, often periodic, propulsion velocity. The precise propulsion velocity profile determines their mean square displacement and their effective…

Soft Condensed Matter · Physics 2024-05-06 Arnau Jurado Romero , Carles Calero , Rossend Rey

Low-dimensional periodic arrays of scatterers with a moving point particle are ideal models for studying deterministic diffusion. For such systems the diffusion coefficient is typically an irregular function under variation of a control…

Chaotic Dynamics · Physics 2009-11-07 R. Klages , N. Korabel

Yeh and Hummer's simplified estimation method has often been adopted to obtain diffusion coefficients for solute molecules using molecular dynamic simulation. However, the simplified formula is not necessarily valid when a small basic cell…

Chemical Physics · Physics 2022-10-19 Tomoya Iwashita , Masaaki Nagao , Akira Yoshimori , Masahide Terazima , Ryo Akiyama

Consider a particle diffusing in a confined volume which is divided into two equal regions. In one region the diffusion coefficient is twice the value of the diffusion coefficient in the other region. Will the particle spend equal…

Dynamical Systems · Mathematics 2015-06-04 P. F. Tupper , Xin Yang

We investigate the evolution of cooling helium atmosphere white dwarfs using a full evolutionary code, specifically developed for following the effects of element diffusion and gravitational settling on white dwarf cooling. The major…

Astrophysics · Physics 2016-08-16 James MacDonald , Margarita Hernanz , Jordi José

We present a prescription for parametrizing the chemical profile in the core of white dwarfs in the light of the recent discovery that pulsation modes may sometimes be deeply confined in some cool pulsating white dwarfs. Such modes may be…

Solar and Stellar Astrophysics · Physics 2017-01-18 N. Giammichele , S. Charpinet , G. Fontaine , P. Brassard

Particle swaps can drastically accelerate dynamics in glass. The mechanism is expected to be vital for a fundamental understanding of glassy dynamics. To extract defining features, we propose a partial swappability with a fraction {\phi_s}…

Disordered Systems and Neural Networks · Physics 2022-11-01 Gautham Gopinath , Chun-Shing Lee , Xin-Yuan Gao , Xiao-Dong An , Chor-Hoi Chan , Cho-Tung Yip , Hai-Yao Deng , Chi-Hang Lam

Dwarf galaxies are thought of as the building blocks of large galaxies such as our Milky Way. This paper presents new high-resolution hydrodynamical simulations of dwarf galaxies and their intergalactic medium with the \texttt{GIZMO} code.…

Astrophysics of Galaxies · Physics 2025-06-06 Pei-Cheng Tung , Ke-Jung Chen

Discrete diffusion models have recently shown significant progress in modeling complex data, such as natural languages and DNA sequences. However, unlike diffusion models for continuous data, which can generate high-quality samples in just…

Machine Learning · Computer Science 2025-03-20 Anji Liu , Oliver Broadrick , Mathias Niepert , Guy Van den Broeck

We calculate interdiffusion coefficients in a two-component, weakly or strongly coupled ion plasma (gas or liquid, composed of two ion species immersed into a neutralizing electron background). We use an effective potential method proposed…

Solar and Stellar Astrophysics · Physics 2015-06-22 M. V. Beznogov , D. G. Yakovlev

We present an investigation into diffusion models for molecular generation, with the aim of better understanding how their predictions compare to the results of physics-based calculations. The investigation into these models is driven by…

The characterization of white dwarf atmospheres is crucial for accurately deriving stellar parameters such as effective temperature, mass, and age. We aim to classify the population of white dwarfs up to 500 pc into hydrogen-rich or…

Generative diffusion models have achieved remarkable success in producing high-quality images. However, these models typically operate in continuous intensity spaces, diffusing independently across pixels and color channels. As a result,…

Graphics · Computer Science 2025-05-20 Javier E. Santos , Agnese Marcato , Roman Colman , Nicholas Lubbers , Yen Ting Lin