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We prove uniform bounds on moments X_a = \sum_{m}{m^a f_m(x,t)} of the Smoluchowski coagulation equations with diffusion, valid in any dimension. If the collision propensities \alpha(n,m) of mass n and mass m particles grow more slowly than…

Analysis of PDEs · Mathematics 2009-11-11 Alan Hammond , Fraydoun Rezakhanlou

We construct a planar diffusion process whose infinitesimal generator depends only on the order of the components of the process. Speaking informally and a bit imprecisely for the moment, imagine you run two Brownian-like particles on the…

Probability · Mathematics 2012-06-19 E. Robert Fernholz , Tomoyuki Ichiba , Ioannis Karatzas , Vilmos Prokaj

In the present report, we have introduced the Fredholm integral method to solve the Smoluchowski equation in the Laplace domain. We get an exact semi-analytical solution for the linear potential energy curve in the dynamic diffusion…

Chemical Physics · Physics 2021-09-03 Chinmoy Samanta , Aniruddha Chakraborty

An approximation is derived for a Langevin equation with distribution-dependent potential and state-dependent, randomly fast oscillation. By some estimates and a diffusion approximation the limiting equation is shown to be…

Probability · Mathematics 2024-03-08 Chungang Shi , Wei Wang

This paper is devoted to the inverse problem of determining the spatially dependent source in a time fractional diffusion-wave equation, with the aid of extra measurement data at subboundary. Uniqueness result is obtained by using the…

Analysis of PDEs · Mathematics 2021-12-08 Xing Cheng , Zhiyuan Li

A study of the diffusion of a passive Brownian particle on the surface of a sphere and subject to the effects of an external potential, coupled linearly to the probability density of the particle's position, is presented through a numerical…

Statistical Mechanics · Physics 2021-08-31 Adriano Valdés Gómez , Francisco J. Sevilla

The paper examines stochastic diffusion within an expanding space-time framework. It starts with providing a rationale for the considered model and its motivation from cosmology where the expansion of space-time is used in modelling various…

Probability · Mathematics 2023-12-22 Philip Broadbridge , Illia Donhauzer , Andriy Olenko

A notion of measure solution is formulated for a coagulation-diffusion equation, which is the natural counterpart of Smoluchowski's coagulation equation in a spatially inhomogeneous setting. Some general properties of such solutions are…

Analysis of PDEs · Mathematics 2014-08-25 James Norris

The Smoluchowski coagulation-diffusion PDE is a system of partial differential equations modelling the evolution in time of mass-bearing Brownian particles which are subject to short-range pairwise coagulation. This survey presents a fairly…

Probability · Mathematics 2019-02-14 Alan Hammond

We obtain the first probabilistic proof of continuous differentiability of time-dependent optimal boundaries in optimal stopping problems. The underlying stochastic dynamics is a one-dimensional, time-inhomogeneous diffusion. The gain…

Probability · Mathematics 2024-05-28 Tiziano De Angelis , Damien Lamberton

We present a new method to solve the dynamics of disordered spin systems on finite time-scales. It involves a closed driven diffusion equation for the joint spin-field distribution, with time-dependent coefficients described by a dynamical…

Condensed Matter · Physics 2009-10-28 A. C. C. Coolen , S. N. Laughton , D. Sherrington

We present a backward diffusion flow (i.e. a backward-in-time stochastic differential equation) whose marginal distribution at any (earlier) time is equal to the smoothing distribution when the terminal state (at a latter time) is…

Probability · Mathematics 2021-10-04 Brian D. O. Anderson , Adrian N. Bishop , Pierre Del Moral , Camille Palmier

A general piecewise (including pointwise) probability distribution with space-saving notation and its hierarchical particular cases are considered. The explicit closed-form normalization, expectation, and variance formulas along with the…

Probability · Mathematics 2022-02-01 Lev Gelimson

The late-time distribution function P(x,t) of a particle diffusing in a one-dimensional logarithmic potential is calculated for arbitrary initial conditions. We find a scaling solution with three surprising features: (i) the solution is…

Statistical Mechanics · Physics 2011-12-15 Ori Hirschberg , David Mukamel , Gunter M. Schütz

It is known that classical solutions to the one-dimensional quasilinear Smoluchowski-Poisson system with nonlinear diffusion $a(u)=(1+u)^{-p}$ may blow up in finite time if $p>1$ and exist globally if $p<1$. The case $p=1$ thus appears to…

Analysis of PDEs · Mathematics 2009-02-20 Tomasz Cieślak , Philippe Laurençot

We show that Langevin$-$Smoluchowski measure on path space is invariant under time-reversal, followed by stochastic control of the drift with a novel entropic-type criterion. Repeated application of these forward-backward steps leads to a…

Probability · Mathematics 2020-11-10 Ioannis Karatzas , Bertram Tschiderer

In the present article we introduce a variant of Smoluchowski's coagulation equation with both position and velocity variables taking a kinetic viewpoint arising as the scaling limit of a system of second-order (microscopic) coagulating…

Analysis of PDEs · Mathematics 2022-11-15 Franco Flandoli , Ruojun Huang , Andrea Papini

The Smoluchowski diffusion equation describes diffusion in the presence of external forces. Studying the mechanical response of soft materials to linear forces, such as shear, results in a boundary value problem involving an…

Numerical Analysis · Mathematics 2026-04-29 Ignacio Labarca-Figueroa , Heiko Gimperlein

The linear Schr\"odinger equation with piecewise constant potential in one spatial dimension is a well-studied textbook problem. It is one of only a few solvable models in quantum mechanics and shares many qualitative features with…

Analysis of PDEs · Mathematics 2018-07-02 Natalie E Sheils , Bernard Deconinck

A physical-mathematical approach to anomalous diffusion may be based on generalized diffusion equations (containing derivatives of fractional order in space or/and time) and related random walk models. The fundamental solution (for the…

Statistical Mechanics · Physics 2007-09-25 Rudolf Gorenflo , Francesco Mainardi , Daniele Moretti , Gianni Pagnini , Paolo Paradisi