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In this work, we investigate the large-scale transport properties of a passive scalar advected by a turbulent fluid, modelled as a superposition of divergence-free vector fields, each weighted by an independent symmetric…

Mathematical Physics · Physics 2026-02-25 Paolo Cifani , Franco Flandoli , Lorenzo Marino

The reaction A+B --> B is studied when the reactants diffuse in phase space, i.e. their dynamics is described by the Langevin equation. The steady-state rate constants are calculated for both the target (static A and mobile B's) and…

Statistical Mechanics · Physics 2009-10-31 D. J. Bicout , A. M. Berezhkovskii , Attila Szabo

A considerable number of systems have recently been reported in which Brownian yet non-Gaussian dynamics was observed. These are processes characterised by a linear growth in time of the mean squared displacement, yet the probability…

Statistical Mechanics · Physics 2018-11-26 V. Sposini , A. V. Chechkin , F. Seno , G. Pagnini , R. Metzler

The~numerical solutions to a non-linear Fractional Fokker--Planck (FFP) equation are studied estimating the generalized diffusion coefficients. The~aim is to model anomalous diffusion using an FFP description with fractional velocity…

Plasma Physics · Physics 2018-10-08 Johan Anderson , Sara Moradi , Tariq Rafiq

Many active particles are embedded in environments that exhibit viscoelastic properties. An important class of such media lacks a single characteristic relaxation timescale when subjected to a time-dependent stress. Rather, the stress…

Soft Condensed Matter · Physics 2025-12-24 David Santiago Quevedo , Monica Conte , Marjolein Dijkstra , Cristiane Morais Smith

Dynamic density functionals (DDFs) are popular tools for studying the dynamical evolution of inhomogeneous polymer systems. Here, we present a systematic evaluation of a set of diffusive DDF theories by comparing their predictions with data…

Soft Condensed Matter · Physics 2018-02-07 Shuanhu Qi , Friederike Schmid

Odd diffusion breaks time-reversal symmetry in overdamped systems through transverse probability currents while preserving equilibrium steady states. In this work, we develop a dynamical density functional theory (DDFT) for dense…

Soft Condensed Matter · Physics 2026-02-02 Iman Abdoli , René Wittmann , Hartmut Löwen

Quasi two-dimensional random site percolation model objects were fabricate based on computer generated templates. Samples consisting of two compartments, a reservoir of H$_2$O gel attached to a percolation model object which was initially…

Condensed Matter · Physics 2009-11-07 Andreas Klemm , Ralf Metzler , Rainer Kimmich

Tracer diffusion in polymer networks and hydrogels is relevant in biology and technology, while it also constitutes an interesting model process for the dynamics of molecules in fluctuating, heterogeneous soft matter. Here, we study…

Soft Condensed Matter · Physics 2024-02-16 Sebastian Milster , Fabian Koch , Christoph Widder , Tanja Schilling , Joachim Dzubiella

The transport phenomenon (movement and diffusion) of inertia Brownian particles in a periodic potential with non-Gaussian noise is investigated. It is found that proper noise intensity Q will promote particles directional movement(or…

Statistical Mechanics · Physics 2019-02-20 Bing Wang , Xiaoxiao Zhang , Yajuan Sun , Zhongwei Qu , Xuechao Li

Anomalous diffusion is an established phenomenon but still a theoretical challenge in non-equilibrium statistical mechanics. Physical models are built incrementally, and the most recent and most general family is based on the fractional…

Probability · Mathematics 2025-07-23 Christian Bender , Yana A. Butko , Mirko D'Ovidio , Gianni Pagnini

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

The molecular motion in heterogeneous media displays anomalous diffusion by the mean-squared displacement $\langle X^2(t) \rangle = 2 D t^\alpha$. Motivated by experiments reporting populations of the anomalous diffusion parameters $\alpha$…

Biological Physics · Physics 2025-10-09 Yann Lanoiselée , Gianni Pagnini , Agnieszka Wyłomańska

Surface diffusion of small adsorbates is analyzed in terms of the so-called intermediate scattering function and dynamic structure factor, observables in experiments using the well-known quasielastic Helium atom scattering and Helium spin…

Statistical Mechanics · Physics 2018-09-26 S. Miret-Artés

We present a numerical investigation of the Brownian motion and diffusion of a dumbbell in a two-dimensional periodic potential. Its dynamics is described by a Langevin model including the hydrodynamic interaction. With increasing values of…

Classical Physics · Physics 2008-09-02 Jochen Bammert , Steffen Schreiber , Walter Zimmermann

We study Brownian motion and the associated Langevin equation in AdS/CFT. The Brownian particle is realized in the bulk spacetime as a probe fundamental string in an asymptotically AdS black hole background, stretching between the AdS…

High Energy Physics - Theory · Physics 2010-06-28 Jan de Boer , Veronika E. Hubeny , Mukund Rangamani , Masaki Shigemori

For the Langevin model of the dynamics of a Brownian particle with perturbations orthogonal to its current velocity, in a regime when the particle velocity modulus becomes constant, an equation for the characteristic function $\psi…

Statistical Mechanics · Physics 2021-03-01 V. A. Doobko , S. V. Zubarev , E. V. Karachanskaya

Chaotic deterministic dynamics of a particle can give rise to diffusive Brownian motion. In this paper, we compute analytically the diffusion coefficient for a particular two-dimensional stochastic layer induced by the kicked Harper map.…

chao-dyn · Physics 2008-02-03 P. Leboeuf

We consider the diffusion-advection problem in two simple cellular flow models (often invoked as examples for subdiffusive tracer's motion) and concentrate on the intermediate time range, in which the tracer's motion indeed may show…

Fluid Dynamics · Physics 2016-09-28 Patrick Pöschke , Igor M. Sokolov , Alexander A. Nepomnyashchy , Michael A. Zaks

We study the Langevin dynamics of diffusive particles with regular pairwise interactions under mean-field scaling. By approximating empirical distributions with conditional distributions, we establish coercive and contractive properties for…

Probability · Mathematics 2026-05-28 Songbo Wang