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We are concerned with the study of the well-posedness of a nonlinear diffusion equation with a monotonically increasing multivalued time-dependent nonlinearity derived from a convex continuous potential having a superlinear growth to…

Analysis of PDEs · Mathematics 2013-07-09 Gabriela Marinoschi

In this paper we reconsider the classical nonlinear diffusivity equation of real gas in an heterogenous porous medium in light of the recent studies about the generalized fractional equation of conservation of mass. We first recall the…

Geophysics · Physics 2016-11-08 A. Caserta , R. Garra , E. Salusti

Diffusion Inverse Solvers (DIS) are designed to sample from the conditional distribution $p_{\theta}(X_0|y)$, with a predefined diffusion model $p_{\theta}(X_0)$, an operator $f(\cdot)$, and a measurement $y=f(x'_0)$ derived from an unknown…

Computer Vision and Pattern Recognition · Computer Science 2024-06-04 Tongda Xu , Ziran Zhu , Jian Li , Dailan He , Yuanyuan Wang , Ming Sun , Ling Li , Hongwei Qin , Yan Wang , Jingjing Liu , Ya-Qin Zhang

We consider boundary value problems with Riemann-Liouville fractional derivatives of order $s\in (1, 2)$ with non-constant diffusion and reaction coefficients. A variational formulation is derived and analyzed leading to the well-posedness…

Numerical Analysis · Mathematics 2025-09-03 Ruben Aylwin , Göksu Oruc , Karsten Urban

We study a kinetic toy model for a spray of particles immersed in an ambient fluid, subject to some additional random forcing given by a mixing, space-dependent Markov process. Using the perturbed test function method, we derive the…

Analysis of PDEs · Mathematics 2020-05-20 Arnaud Debussche , Angelo Rosello , Julien Vovelle

A quantum kinetic equation is obtained for an inhomogeneous solid having arbitrary gradient concentration and chemical potential. We find, starting from nonequilibrium statistical operator, a new equation to describe atom migration in solid…

Statistical Mechanics · Physics 2017-03-31 Y. Bilotsky , M. Gasik , B. Lev

Most systems, when pushed out of equilibrium, respond by building up currents of locally-conserved observables. Understanding how microscopic dynamics determines the averages and fluctuations of these currents is one of the main open…

Statistical Mechanics · Physics 2010-09-08 Pablo I. Hurtado , Pedro L. Garrido

This paper investigates quenching solutions of an one-dimensional, two-sided Riemann-Liouville fractional order convection-diffusion problem. Fractional order spatial derivatives are discretized using weighted averaging approximations in…

Analysis of PDEs · Mathematics 2025-03-06 Rumin Dong , Lin Zhu , Qin Sheng , Bingxin Zhao

We present an approximate and heuristic scheme for the derivation of continuum kinetic equations from microscopic dynamics for stochastic, interacting systems. The method consists of a mean-field type, decoupled approximation of the master…

Statistical Mechanics · Physics 2009-10-31 Kwan-tai Leung

In this paper we present a non-local numerical scheme based on the Local Discontinuous Galerkin method for a non-local diffusive partial differential equation with application to traffic flow. In this model, the velocity is determined by…

Numerical Analysis · Mathematics 2023-11-14 D. Do , H. Nick Zinat Matin , M. L. Delle Monache

Motivated by the statistical description of turbulence, we study statistical conservation laws in the form of kinetic-type PDEs for joint probability density functions (PDFs) and cumulative distribution functions (CDFs) associated with…

Numerical Analysis · Mathematics 2025-09-08 Qian Huang , Christian Rohde

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

This work is devoted to the derivation and the matematical study of a new model for water-soluble polymers and metal ions interactions, which are used in chemistry for their wide range of applications. First, we motivate and derive a model…

Numerical Analysis · Mathematics 2015-09-10 Erwan Hingant , Mauricio Sepúlveda

The interdiffusion of a solvent into a polymer melt has been studied using large scale molecular dynamics and Monte Carlo simulation techniques. The solvent concentration profile and weight gain by the polymer have been measured as a…

Soft Condensed Matter · Physics 2009-11-10 Mesfin Tsige , Gary S. Grest

Self-diffusion along the longitudinal coordinate in a channel of varying cross section is considered. The starting point is the two-dimensional Enskog-Boltzmann-Lorentz kinetic equation with appropriated boundary conditions. It is…

Statistical Mechanics · Physics 2024-07-08 J. Javier Brey , M. I. García de Soria , P. Maynar

We present a novel simulation-free framework for training continuous-time diffusion processes over very general objective functions. Existing methods typically involve either prescribing the optimal diffusion process -- which only works for…

Machine Learning · Computer Science 2025-06-24 Mengjian Hua , Eric Vanden-Eijnden , Ricky T. Q. Chen

We study fast / slow systems driven by a fractional Brownian motion $B$ with Hurst parameter $H\in (\frac 13, 1]$. Surprisingly, the slow dynamic converges on suitable timescales to a limiting Markov process and we describe its generator.…

Probability · Mathematics 2023-03-07 Martin Hairer , Xue-Mei Li

We study the difference between the probability density of a random variable $F$ on Markov diffusion chaos and the probability density of a general target distribution $Z$. In the special case where $F$ is a chaotic random variables and $Z$…

Probability · Mathematics 2025-09-23 Thanh Dang , Yaozhong Hu

This paper derives physically meaningful boundary conditions for fractional diffusion equations, using a mass balance approach. Numerical solutions are presented, and theoretical properties are reviewed, including well-posedness and steady…

Analysis of PDEs · Mathematics 2017-06-27 Boris Baeumer , Mihály Kovács , Mark M. Meerschaert , Harish Sankaranarayanan

In the present work, we consider the Cauchy problem for the time fractional diffusion equation involving the general Caputo-type differential operator proposed by Kochubei. First, the existence, the positivity and the long time behavior of…

Analysis of PDEs · Mathematics 2022-02-28 Chung-Sik Sin