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Related papers: Diffusion and Velocity Auto-Correlation in Shearin…

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We present a concise, self-contained derivation of diffusion-based generative models. Starting from basic properties of Gaussian distributions (densities, quadratic expectations, re-parameterisation, products, and KL divergences), we…

Machine Learning · Computer Science 2025-11-18 Sepehr Maleki , Negar Pourmoazemi

We investigate numerically the dynamics of a single polymer in a linear shear flow. The effects of thermal fluctuations and randomly fluctuating velocity gradients are both analyzed. Angular, elongation and tumbling time statistics are…

Chaotic Dynamics · Physics 2009-11-11 A. Puliafito , K. Turitsyn

Particle diffusion in rotating drums is studied via computer simulations using a full 3-D model which does not involve any arbitrary input parameters. The diffusion coefficient for single-component systems agree qualitatively with previous…

Condensed Matter · Physics 2009-10-28 G. A. Kohring

The Green-Kubo formula relates the spatial diffusion coefficient to the stationary velocity autocorrelation function. We derive a generalization of the Green-Kubo formula valid for systems with long-range or nonstationary correlations for…

Statistical Mechanics · Physics 2014-03-05 A. Dechant , E. Lutz , D. A. Kessler , E. Barkai

Many important properties of granular fluids can be represented by a system of hard spheres with inelastic collisions. Traditional methods of nonequilibrium statistical mechanics are effective for analysis and description of the inelastic…

Soft Condensed Matter · Physics 2009-11-07 James W. Dufty , J. Javier Brey , James Lutsko

Granular materials such as sand, powders, and grains are omnipresent in daily life, industrial applications, and earth-science [1]. When unperturbed, they form stable structures that resemble the ones of other amorphous solids like metallic…

Soft Condensed Matter · Physics 2023-01-19 Ye Yuan , Zhikun Zeng , Yi Xing , Houfei Yuan , Shuyang Zhang , Walter Kob , Yujie Wang

We consider the increase of the spatial variance of some inhomogeneous, non-equilibrium density (particles, energy, etc.) in a periodic quantum system of condensed matter-type. This is done for a certain class of initial quantum states…

Statistical Mechanics · Physics 2009-10-23 Robin Steinigeweg , Hannu Wichterich , Jochen Gemmer

We present results on a meso-scale model for amorphous matter in athermal, quasi-static (a-AQS), steady state shear flow. In particular, we perform a careful analysis of the scaling with the lateral system size, $L$, of: i) statistics of…

Soft Condensed Matter · Physics 2019-10-30 Botond Tyukodi , Damien Vandembroucq , Craig E Maloney

We study lower and upper bounds for the density of a diffusion process in ${\mathbb{R}}^n$ in a small (but not asymptotic) time, say $\delta$. We assume that the diffusion coefficients $\sigma_1,\ldots,\sigma_d$ may degenerate at the…

Probability · Mathematics 2019-12-03 Vlad Bally , Lucia Caramellino , Paolo Pigato

The relevance of the vortex-gas model to the large scale dynamics of temporally evolving turbulent free shear layers in an inviscid incompressible fluid has recently been established by extensive numerical simulations (Suryanarayanan et al,…

Fluid Dynamics · Physics 2015-09-04 Saikishan Suryanarayanan , Roddam Narasimha

A microemulsion of decane droplets stabilized by a non-ionic surfactant film is progressively charged by substitution of a non-ionic surfactant molecule by a cationic surfactant. We check that the microemulsion droplets remain identical…

Soft Condensed Matter · Physics 2016-08-16 Jacqueline Appell , Grégoire Porte , Eric Buhler

The velocity distribution in a homogeneously cooling granular gas has been studied in the viscoelastic regime when the restitution coefficient of colliding particles depends on the impact velocity. We show that for viscoelastic particles…

Statistical Mechanics · Physics 2009-10-31 Nikolai V. Brilliantov , Thorsten Poeschel

We studied the macroscopic statistical properties on the freely evolving quasi-elastic hard disk (granular) system by performing a large-scale (up to a few million particles) event-driven molecular dynamics systematically and found that…

Condensed Matter · Physics 2008-05-05 Masaharu Isobe

We study the scale dependence of effective diffusion of fluid tracers, specifically, its dependence on the P\'{e}clet number, a dimensionless parameter of the ratio between advection and molecular diffusion. Here, we address the case that…

Fluid Dynamics · Physics 2022-04-13 Yohei Kono , Yoshihiko Susuki , Takashi Hikihara

A new first-principles statistical mechanics formulation is proposed to describe slow and dilated granular fluids, where prolonged intergranular contacts vitiate collision theory. The contacts, where all the important physics takes place,…

Soft Condensed Matter · Physics 2016-03-08 Raphael Blumenfeld

We analyze magnetic kinematic dynamo in a conducting fluid where the stationary shear flow is accompanied by relatively weak random velocity fluctuations. The diffusionless and diffusion regimes are described. The growth rates of the…

Chaotic Dynamics · Physics 2015-05-20 I. Kolokolov , V. Lebedev , G. Sizov

We present here the preliminary results obtained for two experiments on randomly agitated granular assemblies using a novel way of shaking. First we discuss the transport properties of a 2D model system undergoing classical shaking that…

Statistical Mechanics · Physics 2009-11-10 G. Caballero , A. Lindner , G. Ovarlez , G. Reydellet , J. Lanuza , E. Clement

We use 2D numerical simulations to study dense suspensions of non-Brownian hard particles using the Critical Load Model (CLM) under constant confining pressures. This simple model shows discontinuous shear thickening (DST) as the tangential…

Soft Condensed Matter · Physics 2017-09-06 Junhao Dong , Martin Trulsson

Experiments with acoustic waves guided along the mechanically free surface of an unconsolidated granular packed structure provide information on the elasticity of granular media at very low pressures that are naturally controlled by the…

We report simulations of a two-dimensional, dense, bidisperse system of inelastic hard disks falling down a vertical tube under the influence of gravity. We examine the approach to jamming as the average flow of particles down the tube is…

Soft Condensed Matter · Physics 2009-11-13 Shubha Tewari , Bidita Tithi , Allison Ferguson , Bulbul Chakraborty