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Turing instabilities of reaction-diffusion systems can only arise if the diffusivities of the chemical species are sufficiently different. This threshold is unphysical in most systems with $N=2$ diffusing species, forcing experimental…

Soft Condensed Matter · Physics 2026-03-17 Pierre A. Haas , Raymond E. Goldstein

In this work we use tempered fractional advection-diffusion equations to model the dispersive transport in disordered materials. A numerical method is derived to approximate the solution of such differential models and we prove that it is…

Numerical Analysis · Mathematics 2018-11-06 Maria Luísa Morgado , Luís Filipe Morgado

We perform molecular dynamic simulations of liquid nanoparticles deposited on a disordered substrate. The motion of the nanoparticle is characterised by a 'stick and roll' diffusive process. Long simulation times ($\simeq \mu s$), analysis…

Materials Science · Physics 2009-11-10 F. Celestini

Diffusion in an evolving environment is studied by continuos-time Monte Carlo simulations. Diffusion is modelled by continuos-time random walkers on a lattice, in a dynamic environment provided by bubbles between two one-dimensional…

Soft Condensed Matter · Physics 2010-11-22 Janne Juntunen , Juha Merikoski

Tracking of individual particle and studying their motion serves as a direct means to understand the dynamics in crowded and complex environments. In this study, the dynamics of tracer particles in the matrix of dense soft-colloidal…

Soft Condensed Matter · Physics 2023-06-28 Jimpaul Samukcham , Lenin S. Shagolsem

A topic of intense current investigation pursues the question how the highly crowded environment of biological cells affects the dynamic properties of passively diffusing particles. Motivated by recent experiments we report results of…

Statistical Mechanics · Physics 2016-09-28 Surya K. Ghosh , Andrey G. Cherstvy , Denis S. Grebenkov , Ralf Metzler

Interacting particles diffusing in single-file is a fundamental model of transport in narrow channels where particles cannot bypass each other. An important result has been obtained by Kollmann [Phys. Rev. Lett. 90, 180602 (2003)] for the…

Statistical Mechanics · Physics 2025-07-24 Théotim Berlioz , Olivier Bénichou , Aurélien Grabsch

We present an accessible first course on diffusion models and flow matching for machine learning, aimed at a technical audience with no diffusion experience. We try to simplify the mathematical details as much as possible (sometimes…

Machine Learning · Computer Science 2024-06-25 Preetum Nakkiran , Arwen Bradley , Hattie Zhou , Madhu Advani

The diffusion and flow of amorphous materials, such as glasses and granular materials, has resisted a simple microscopic description, analogous to defect theories for crystals. Early models were based on either gas-like inelastic collisions…

Statistical Mechanics · Physics 2007-05-23 Martin Z. Bazant

Aggregation and fragmentation of single molecules in the cell environment lead to a spectrum of diffusivities and to statistical laws of movement very different from typical Brownian motion. Current models of intracellular transport do not…

Statistical Mechanics · Physics 2020-07-08 M. Hidalgo-Soria , E. Barkai

Diffusion models are loosely modelled based on non-equilibrium thermodynamics, where \textit{diffusion} refers to particles flowing from high-concentration regions towards low-concentration regions. In statistics, the meaning is quite…

Machine Learning · Computer Science 2023-12-19 Inga Strümke , Helge Langseth

Animals use stereo sampling of odor concentration to localize sources and follow odor trails. We analyze the dynamics of a bilateral model that depends on the simultaneous comparison between odor concentrations detected by left and right…

Quantitative Methods · Quantitative Biology 2021-03-16 Nour Riman , Jonathan D. Victor , Sebastian D. Boie , Bard Ermentrout

Many physical phenomena occur on domains that grow in time. When the timescales of the phenomena and domain growth are comparable, models must include the dynamics of the domain. A widespread intrinsically slow transport process is…

Statistical Mechanics · Physics 2017-11-01 C. N. Angstmann , B. I. Henry , A. V. McGann

Object tracking is a fundamental task in computer vision, requiring the localization of objects of interest across video frames. Diffusion models have shown remarkable capabilities in visual generation, making them well-suited for…

Computer Vision and Pattern Recognition · Computer Science 2024-10-15 Pha Nguyen , Ngan Le , Jackson Cothren , Alper Yilmaz , Khoa Luu

Data scarcity drives the need for more sample-efficient large language models. In this work, we use the double descent phenomenon to holistically compare the sample efficiency of discrete diffusion and autoregressive models. We show that…

Machine Learning · Computer Science 2025-09-30 Ahmad Fraij , Sam Dauncey

The study of pattern emergence together with exploration of the exemplar Turing model is enjoying a renaissance both from theoretical and experimental perspective. Here, we implement a stability analysis of spatially dependent reaction…

Pattern Formation and Solitons · Physics 2019-11-06 Michal Kozák , Eamonn A Gaffney , Václav Klika

Generating physically plausible human motion is crucial for applications such as character animation and virtual reality. Existing approaches often incorporate a simulator-based motion projection layer to the diffusion process to enforce…

Computer Vision and Pattern Recognition · Computer Science 2025-09-26 Akihisa Watanabe , Jiawei Ren , Li Siyao , Yichen Peng , Erwin Wu , Edgar Simo-Serra

When very small particles are suspended in a fluid in motion, they tend to follow the flow. How such tracer particles are mixed, transported, and dispersed by turbulent flow has been successfully described by statistical models. Heavy…

Fluid Dynamics · Physics 2023-12-21 J. Bec , K. Gustavsson , B. Mehlig

A model for diffusion in liquids that couples the dynamics of tracer particles to a fluctuating Stokes equation for the fluid is investigated in the limit of large Schmidt number. In this limit, the concentration of tracers is shown to…

Statistical Mechanics · Physics 2014-04-03 A. Donev , T. G. Fai , and E. Vanden-Eijnden

Diffusion-driven patterns appear on curved surfaces in many settings, initiated by unstable modes of an underlying Laplacian operator. On a flat surface or perfect sphere, the patterns are degenerate, reflecting translational/rotational…

Soft Condensed Matter · Physics 2025-09-09 John R. Frank , Jemal Guven , Mehran Kardar , Leyna Shackleton