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Related papers: Diffusion in a continuum model of self-propelled p…

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The eigenfunctions and eigenvalues of the linearized Boltzmann equation for inelastic hard spheres (d=3) or disks (d=2) corresponding to d+2 hydrodynamic modes, are calculated in the long wavelength limit for a granular gas. The transport…

Statistical Mechanics · Physics 2009-11-10 James W. Dufty , J. Javier Brey

Starting from a minimal physical model of self propelled hard rods on a substrate in two dimensions, we derive a modified Smoluchowski equation for the system. Self -propulsion enhances longitudinal diffusion and modifies the mean field…

Soft Condensed Matter · Physics 2009-11-13 Aparna Baskaran , M. Cristina Marchetti

We proposed a new extended version of Enskog theory for the description of the self-diffusion coefficient of a colloidal hard-sphere fluid adsorbed in a matrix of disordered hard-sphere obstacles. In a considered approach instead of contact…

Soft Condensed Matter · Physics 2025-06-26 M. F. Holovko , M. Ya. Korvatska

Assuming that a reflected Ornstein-Uhlenbeck state process is observed at discrete time instants, we propose generalized moment estimators to estimate all drift and diffusion parameters via the celebrated ergodic theorem. With the sampling…

Statistics Theory · Mathematics 2020-09-14 Yaozhong Hu , Yuejuan Xi

We reconsider some fundamental aspects of the fluid mechanics model, and the derivation of continuum flow equations from gas kinetic theory. Two topologies for fluid representation are presented, and a set of macroscopic equations are…

Fluid Dynamics · Physics 2007-05-23 S. Kokou Dadzie , Jason M. Reese , Colin R. McInnes

Diffusion of a two component fluid is studied in the framework of differential equations, but where these equations are systematically derived from a well-defined microscopic model. The model has a finite carrying capacity imposed upon it…

Statistical Mechanics · Physics 2015-06-04 D. Fanelli , A. J. McKane , G. Pompili , B. Tiribilli , M. Vassalli , T. Biancalani

We propose a specific scaling that formally derives the Euler-Vlasov model for thick sprays which is widely adopted in engineering from the Boltzmann-Enskog model. Beyond validating the kinetic-fluid equations underlying this model, we also…

Analysis of PDEs · Mathematics 2025-09-08 Zhe Chen

We study the Fokker-Planck diffusion equation with diffusion coefficient depending periodically on the space variable. Inside a periodic array of inclusions the diffusion coefficient is reduced by a factor called the diffusion magnitude. We…

Analysis of PDEs · Mathematics 2024-06-03 M. Amar , D. Andreucci , E. N. M. Cirillo

Brownian motion is essential for describing diffusion in systems ranging from simple to complex liquids. Unlike simple liquids, which consist of only a solvent, complex liquids, such as colloidal suspensions or the cytoplasm of a cell, are…

Soft Condensed Matter · Physics 2025-02-27 Jeffrey C. Everts , Robert Hołyst , Karol Makuch

We consider a class of time-homogeneous diffusion processes on $\mathbb{R}^{n}$ with common invariant measure but varying volatility matrices. In Euclidean space, we show via stochastic control of the diffusion coefficient that the…

Probability · Mathematics 2023-10-31 Bertram Tschiderer

We present the perturbative solution of the multicomponent Boltzmann kinetic equation based on the set of observables including the hydrodynamic velocity and temperature for each component. The solution is obtained by modifying the formal…

Statistical Mechanics · Physics 2008-01-23 S. V. Savenko , E. A. J. F. Peters , P. J. A. M. Kerkhof

To analyze hydration effects on macromolecular diffusion, the friction coefficients of macromolecules were examined using molecular dynamics simulations with an all-atom model. In the present study, a method was introduced to decompose the…

Biological Physics · Physics 2024-09-26 Tomoya Iwashita , Yuki Uematsu , Masahide Terazima , Ryo Akiyama

Comparison of hydrodynamic and "hybrid" hydrodynamics+transport calculations to heavy-ion data inevitably requires the conversion of the fluid to particles. For dissipative fluids the conversion is ambiguous without additional theory input…

Nuclear Theory · Physics 2017-02-22 Denes Molnar , Zack Wolff

We derive rigorously from the water waves equations new irrotational shallow water models for the propagation of surface waves in the case of uneven topography in horizontal dimensions one and two. The systems are made to capture the…

Analysis of PDEs · Mathematics 2023-11-17 Louis Emerald , Martin Oen Paulsen

We describe numerical simulations of the stochastic diffusion equation with a conserved charge. We focus on the dynamics in the vicinity of a critical point in the Ising universality class. The model we consider is expected to describe the…

Nuclear Theory · Physics 2023-10-17 Chandrodoy Chattopadhyay , Josh Ott , Thomas Schaefer , Vladimir Skokov

We study the interaction of a fast moving particle in the Quark Gluon Plasma with linearized hydrodynamics. We derive the linearized hydrodynamic equations on top of an expanding fireball, and detail the solutions for a static medium. There…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Casalderrey-Solana , E. V. Shuryak , D. Teaney

We present a microscopic derivation of the nonlinear fluctuating hydrodynamic equation for the homogeneous crystalline solid from the Hamiltonian description of a many-particle system. We propose a microscopic expression of the displacement…

Statistical Mechanics · Physics 2024-03-21 Ken Hiura

Traditionally, the deformation of continuum is divided into elastic, plastic, and flow. For a large deformation with cracking, they are combined together. So, for complicated deformation, a formulation to express the evolution of…

Classical Physics · Physics 2007-05-23 Jianhua Xiao

We propose a fluidic continuum model of vacuum and a sink flow model of microscopic particles. The movements of a microscopic particle driven by a stochastic force was studied based on stochastic mechanics. We show that there exists a…

General Physics · Physics 2024-05-09 Xiao-Song Wang

We provide new convergence guarantees in Wasserstein distance for diffusion-based generative models, covering both stochastic (DDPM-like) and deterministic (DDIM-like) sampling methods. We introduce a simple framework to analyze…

Machine Learning · Computer Science 2025-11-14 Eliot Beyler , Francis Bach