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Related papers: Continuum theory of vacancy-mediated diffusion

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Turbulent flows are out-of-equilibrium because the energy supply at large scales and its dissipation by viscosity at small scales create a net transfer of energy among all scales. Here, the energy cascade is approximated by a combined…

Fluid Dynamics · Physics 2021-01-11 Amilcare Porporato , Milad Hooshyar , Andrew D Bragg , Gabriel Katul

A semiclassical kinetic theory is presented for the fluctuating photon flux emitted by a disordered medium in thermal equilibrium. The kinetic equation is the optical analog of the Boltzmann-Langevin equation for electrons. Vacuum…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. G. Mishchenko , C. W. J. Beenakker

Using granular experiments and computer simulations, we investigate the long-time diffusion of active tracers in a broad class of complex media composed of frozen obstacles of diverse structures. By introducing a dimensionless persistence…

Soft Condensed Matter · Physics 2025-05-06 Qun Zhang , Yuxin Tian , Xue Zhang , Xiaoting Yu , Hongwei Zhu , Ning Zheng , Luhui Ning , Ran Ni , Mingcheng Yang , Peng Liu

We introduce non-trivial contributions to diffusion constant in generic many-body systems arising from quadratic fluctuations of ballistically propagating, i.e. convective, modes. Our result is obtained by expanding the current operator in…

Statistical Mechanics · Physics 2020-11-25 Marko Medenjak , Jacopo De Nardis , Takato Yoshimura

We study the position of a biased tracer particle (TP) in a bath of hardcore particles moving on a lattice of arbitrary dimension and in contact with a reservoir. Starting from the master equation satisfied by the joint probability of the…

Statistical Mechanics · Physics 2015-12-09 Pierre Illien , Olivier Bénichou , Gleb Oshanin , Raphaël Voituriez

We consider a driven tracer particle (TP) in a bath of hard-core particles undergoing continuous exchanges with a reservoir. We develop an analytical framework which allows us to go beyond the standard force-velocity relation used for this…

Statistical Mechanics · Physics 2015-06-15 O. Bénichou , P. Illien , G. Oshanin , R. Voituriez

A formalism using a double Laplace Fourier transform of the transport equation yields the return probabilities of the vacancy in the vicinity of the tracer atom in the presence of solute-vacancy interactions of arbitrary extension. Studying…

Materials Science · Physics 2016-10-11 J. L. Bocquet

Standard and anomalous transport in incompressible flow is investigated using multiscale techniques. Eddy-diffusivities emerge from the multiscale analysis through the solution of an auxiliary equation. From the latter it is derived an…

Condensed Matter · Physics 2009-10-22 L. Biferale , A. Crisanti , M. Vergassola , A. Vulpiani

Understanding transport processes in complex nanoscale systems, like ionic conductivities in nanofluidic devices or heat conduction in low dimensional solids, poses the problem of examining fluctuations of currents within nonequilibrium…

Mesoscale and Nanoscale Physics · Physics 2021-08-04 David T. Limmer , Chloe Y. Gao , Anthony R. Poggioli

On the basis of perturbed Kolmogorov backward equations and path integral representation, we unify the derivations of the linear response theory and transient fluctuation theorems for continuous diffusion processes from a backward point of…

Statistical Mechanics · Physics 2015-05-14 Fei Liu , Zhong-can Ou-Yang

A rather simple random walk model on a one-dimensional lattice is put forward. The lattice as a whole switches randomly between two possible states which are spatially symmetric. Both lattice states are identical, but translated by one site…

Statistical Mechanics · Physics 2016-08-16 Jesús Casado-Pascual

The propagation of cosmic rays can be described as a diffusive motion in most galactic environments. High-energy gamma-rays measured by Fermi have allowed inference of a gradient in the cosmic-ray density and spectral energy behavior in the…

High Energy Astrophysical Phenomena · Physics 2021-10-14 J. Dörner , P. Reichherzer , L. Merten , J. Becker Tjus , H. Fichtner , M. J. Pueschel , E. G. Zweibel

Starting from a general classical model of many interacting particles we present a well defined step by step procedure to derive the continuum-mechanics equations of nonlinear elasticity theory with fluctuations which describe the…

Statistical Mechanics · Physics 2022-06-02 Rudolf Haussmann

Diffusion Transformer, the backbone of Sora for video generation, successfully scales the capacity of diffusion models, pioneering new avenues for high-fidelity sequential data generation. Unlike static data such as images, sequential data…

Machine Learning · Computer Science 2025-02-05 Hengyu Fu , Zehao Dou , Jiawei Guo , Mengdi Wang , Minshuo Chen

A conditional diffusion model has been developed to analyze intricate conductance fluctuations called universal conductance fluctuations or quantum fingerprints appearing in quantum transport phenomena. The model reconstructs impurity…

Mesoscale and Nanoscale Physics · Physics 2025-06-11 Naoto Yokoi , Yuki Tanaka , Yukito Nonaka , Shunsuke Daimon , Junji Haruyama , Eiji Saitoh

The Euler and Navier-Stokes fluid mechanics equations are derived using a modified statistical mechanical approach using theory taken from the Chapman-Enskog perturbation analysis used to support the lattice Boltzmann method. Additional…

Fluid Dynamics · Physics 2021-07-06 Charles Cook

We solve two problems related to the fluctuations of time-integrated functionals of Markov diffusions, used in physics to model nonequilibrium systems. In the first we derive and illustrate the appropriate boundary conditions on the…

Statistical Mechanics · Physics 2023-02-01 Johan du Buisson

Recent advances in data-driven modeling have shown that diffusion models can successfully generate synthetic Lagrangian trajectories in turbulent flows. Building on this progress, we extend the method to the joint generation of pairs of…

We calculate the diffusion coefficient of an active tracer in a schematic crowded environment, represented as a lattice gas of passive particles with hardcore interactions. Starting from the master equation of the problem, we put forward a…

Statistical Mechanics · Physics 2022-02-02 Pierre Rizkallah , Alessandro Sarracino , Olivier Bénichou , Pierre Illien

This article is concerned with the fluctuation analysis and the stability properties of a class of one-dimensional Riccati diffusions. These one-dimensional stochastic differential equations exhibit a quadratic drift function and a…

Probability · Mathematics 2019-02-04 Adrian N. Bishop , Pierre Del Moral , Kengo Kamatani , Bruno Remillard