Abstract

The Continuous Time Random Walk and the Finite Difference Method for the Space Time Fractional Diffusion Equations

Highlights

  • In 1827 an English botanist, Robert Brown, noticed that small particles suspended in fluids perform peculiarly erratic movements. This phenomenon, which can be observed in gases, is referred to as Brownian motion [1]

  • Einstein considered the case of the free particle, that is, a particle in which no forces other than those due to the molecules of the surrounding medium are acting. He was able to show that the probability density u ( x, t ) must satisfy the partial differential equation where a > 0 is a certain physical constant

  • The extension to Lévy stable motion is a straight forward generalization due to the common properties of Lévy stable motion and Brownian motion, but the Lévy flights differ from the regular Brownian motion by the occurrence of extremely long jumps whose length is distributed according to the Lévy long tail x −1−α, 0 < α < 2 Many physical, biological, medical, and chemical models exhibits a power law with a non integer frequency of order t−β, where 0 < β < 1. for diffusion processes and 0 < β < 2 for wave propagation

Read more

Summary

Fractional Diffusion Equations

The space fractional diffusion equations are a linear partial pseudo-differential equation with spatial fractional derivatives in space This equation arises when the motion of the particle is not Brownian and there are extremely long jumps whose length is distributed according to the Lévy long tail x −1−α , 0 < α < 2 Some physical, biological and chemical models exhibit a power law with a non integer frequency of order t−β , 0 < β < 1. In this case, one needs to replace the first order time differential operator by the Caputo time fractional operator.

Introduction
Biostatistics and Biometrics Open Access Journal
Important notations
While f dn
The approximating of x
The time fractional derivative operator of order is defined as
The space fractional diffusion with central linear drift reads
Time fractional Ehrenfest model
An Eβ
Definition of the reversibility property
Potential operator
Numerical Result
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.