Superposition principle for non-local Fokker–Planck–Kolmogorov operators

2020 ◽  
Vol 178 (3-4) ◽  
pp. 699-733
Author(s):  
Michael Röckner ◽  
Longjie Xie ◽  
Xicheng Zhang
Entropy ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 760 ◽  
Author(s):  
Johan Anderson ◽  
Sara Moradi ◽  
Tariq Rafiq

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 derivatives and Langevin dynamics where Lévy fluctuations are introduced to model the effect of non-local transport due to fractional diffusion in velocity space. Distribution functions are found using numerical means for varying degrees of fractionality of the stable Lévy distribution as solutions to the FFP equation. The statistical properties of the distribution functions are assessed by a generalized normalized expectation measure and entropy and modified transport coefficient. The transport coefficient significantly increases with decreasing fractality which is corroborated by analysis of experimental data.


2020 ◽  
Vol 17 (04) ◽  
pp. 809-841
Author(s):  
Paulo Amorim ◽  
Florent Berthelin ◽  
Thierry Goudon

We consider a non-local scalar conservation law in two space dimensions which arises as the formal hydrodynamic limit of a Fokker–Planck equation. This Fokker–Planck equation is, in turn, the kinetic description of an individual-based model describing the navigation of self-propelled particles in a pheromone landscape. The pheromone may be linked to the agent distribution itself, leading to a nonlinear, non-local scalar conservation law where the effective velocity vector depends on the pheromone field in a small region around each point, and thus, on the solution itself. After presenting and motivating the problem, we present some numerical simulations of a closely related problem, and then prove a well-posedness and stability result for the conservation law.


Author(s):  
Shaurya Kaushal ◽  
Santosh Ansumali ◽  
Bruce Boghosian ◽  
Merek Johnson

Recent work on agent-based models of wealth distribution has yielded nonlinear, non-local Fokker–Planck equations whose steady-state solutions describe empirical wealth distributions with remarkable accuracy using only a few free parameters. Because these equations are often used to solve the ‘inverse problem’ of determining the free parameters given empirical wealth data, there is much impetus to find fast and accurate methods of solving the ‘forward problem’ of finding the steady state corresponding to given parameters. In this work, we derive and calibrate a lattice Boltzmann equation for this purpose. This article is part of the theme issue ‘Fluid dynamics, soft matter and complex systems: recent results and new methods’.


2019 ◽  
Vol 29 (02) ◽  
pp. 209-235 ◽  
Author(s):  
Jukka Kemppainen ◽  
Rico Zacher

We consider a rather general class of non-local in time Fokker–Planck equations and show by means of the entropy method that as [Formula: see text], the solution converges in [Formula: see text] to the unique steady state. Important special cases are the time-fractional and ultraslow diffusion case. We also prove estimates for the rate of decay. In contrast to the classical (local) case, where the usual time derivative appears in the Fokker–Planck equation, the obtained decay rate depends on the entropy, which is related to the integrability of the initial datum. It seems that higher integrability of the initial datum leads to better decay rates and that the optimal decay rate is reached, as we show, when the initial datum belongs to a certain weighted [Formula: see text] space. We also show how our estimates can be adapted to the discrete-time case thereby improving known decay rates from the literature.


2019 ◽  
Vol 100 (1) ◽  
pp. 363-366
Author(s):  
V. I. Bogachev ◽  
M. Röckner ◽  
S. V. Shaposhnikov

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 191-196 ◽  
Author(s):  
Günter Mahler ◽  
Rainer Wawer

The superposition principle makes quantum networks behave very differently from their classical counterparts: We discuss how local and non-local coherence are generated and how these may affect the function of composite systems. Numerical examples concern quantum trajectories, quantum noise and quantum parallelism.


2008 ◽  
Vol 112 (2) ◽  
pp. 022044
Author(s):  
M Chen ◽  
Y Kishimoto ◽  
J Q Li ◽  
W B Pei

Sign in / Sign up

Export Citation Format

Share Document