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We address the dynamics of adsorbed molecules (a fundamental issue in surface physics) within the framework of a Master Equation scheme, and study the diffusion of particles in a finite cubic lattice whose boundaries are at the $z=1$ and…

Statistical Mechanics · Physics 2009-11-10 Jorge A. Revelli , Carlos. E. Budde , Domingo Prato , Horacio S. Wio

The Diffusion Monte Carlo method is devoted to the computation of electronic ground-state energies of molecules. In this paper, we focus on implementations of this method which consist in exploring the configuration space with a {\bf fixed}…

Numerical Analysis · Mathematics 2007-05-23 Tony Lelievre , Mohamed El Makrini , Benjamin Jourdain

The transport of charged particles in various astrophysical environments permeated by magnetic fields is described in terms of a diffusion process, which relies on diffusion-tensor parameters generally inferred from Monte-Carlo simulations.…

High Energy Astrophysical Phenomena · Physics 2022-12-09 Olivier Deligny

A survey is given on asymptotic diffusion coefficients of particles in lattices with random transition rates. Exact and approximate results for single particles are reviewed. A recent exact expression in $d = 1$ which includes occupation…

Condensed Matter · Physics 2007-05-23 K. W. Kehr , T. Wichmann

Brownian motion is the perpetual irregular motion exhibited by small particles immersed in a fluid. Such random motion of the particles is produced by statistical fluctuations in the collisions they suffer with the molecules of the…

Physics Education · Physics 2007-05-23 Kasturi Basu , Kopinjol Baishya

Fluorescent molecules emit light in a dipole radiation pattern that can be used to infer their orientation through defocused fluorescence microscopy. Proper measurement of the orientation requires mathematical modeling of the radiation…

Optics · Physics 2025-08-07 E. Dey , M. Elorza , F. W. Foss , J. J. Gomez Cadenas , B. J. P. Jones

Foams are ideal model systems to study stress-driven dynamics, as stress-imbalances within the system are continuously generated by the coarsening process, which unlike thermal fluctuations, can be conveniently quantified by optical means.…

Soft Condensed Matter · Physics 2010-09-29 David A. Sessoms , Hugo Bissig , Agnès Duri , Luca Cipelletti , Véronique Trappe

Diffusion is a fundamental physical phenomenon with critical applications in fields such as metallurgy, cell biology, and population dynamics. While standard diffusion is well-understood, anomalous diffusion often requires complex non-local…

Statistical Mechanics · Physics 2026-01-16 Gabriel Barreiro , Vladimir Pérez-Veloz

We derive analytical expressions to describe how light is frequency-shifted when interacting with ultrasound within scattering media, due to the modulation of the refractive index induced by the ultrasound pressure waves. The model is…

Optics · Physics 2024-10-16 Adam Kinos

We model the evolution of the concentration field of macromolecules in a symmetric field-flow fractionation (FFF) channel by a one-dimensional advection-diffusion equation. The coefficients are precisely determined from the fluid dynamics.…

chao-dyn · Physics 2007-05-23 S. A. Suslov , A. J. Roberts

The diffusion in two dimensions of non-interacting active particles that follow an arbitrary motility pattern is considered for analysis. Accordingly, the transport equation is generalized to take into account an arbitrary distribution of…

Statistical Mechanics · Physics 2020-09-01 Francisco J. Sevilla

We study the influence of the propagation effects on the mean profiles of radio pulsars using the Kravtsov-Orlov method of the wave propagation in the inhomogeneous media. This approach allows us firstly to include into consideration the…

High Energy Astrophysical Phenomena · Physics 2015-05-28 V. S. Beskin , A. A. Philippov

Diffusion tensor coefficients play a central role in describing cosmic-ray transport in various astrophysical environments permeated with magnetic fields, which are usually modeled as a fluctuating field on top of a mean field. In this…

High Energy Astrophysical Phenomena · Physics 2024-07-09 O. Deligny

The short--time self diffusion coefficient of a sphere in a suspension of rigid rods is calculated in first order in the rod volume fraction. For low rod concentrations the correction to the Einstein diffusion constant of the sphere is a…

Soft Condensed Matter · Physics 2008-12-03 J. Guzowski , B. Cichocki , E. Wajnryb , G. C. Abade

The interdiffusion of a solvent into a polymer melt has been studied using large scale molecular dynamics and Monte Carlo simulation techniques. The solvent concentration profile and weight gain by the polymer have been measured as a…

Soft Condensed Matter · Physics 2009-11-10 Mesfin Tsige , Gary S. Grest

We study by simulation the effect of the diffusive motion of repressor molecules on the noise in mRNA and protein levels in the case of a repressed gene. We find that spatial fluctuations due to diffusion can drastically enhance the noise…

Molecular Networks · Quantitative Biology 2007-05-23 Jeroen S. van Zon , Marco J. Morelli , Sorin Tanase-Nicola , Pieter Rein ten Wolde

Diffusion-mediated surface phenomena are crucial for human life and industry, with examples ranging from oxygen capture by lung alveolar surface to heterogeneous catalysis, gene regulation, membrane permeation and filtration processes.…

Statistical Mechanics · Physics 2020-08-19 Denis S. Grebenkov

Spectral diffusion is a result of random spectral jumps of a narrow line as a result of a fluctuating environment. It is an important issue in spectroscopy, because the observed spectral broadening prevents access to the intrinsic line…

We consider subtle correlations in the scattering of fluid by randomly placed obstacles, which have been suggested to lead to a diverging dispersion coefficient at long times for high Peclet numbers, in contrast to finite mean-field…

Statistical Mechanics · Physics 2009-11-07 Michael W. Deem , Jeong-Man Park

The propagation of light in a resonant atomic vapor can \textit{a priori} be thought of as a multiple scattering process, in which each scattering event redistributes both the direction and the frequency of the photons. Particularly, the…

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