29 research outputs found
The cauchy problem for the multi-time ractional diffusion equation
In this work, we study the following problem: find a regular solution и = u(x, y
Approximate Solutions to Fractional Subdiffusion Equations: The heat-balance integral method
The work presents integral solutions of the fractional subdiffusion equation
by an integral method, as an alternative approach to the solutions employing
hypergeometric functions. The integral solution suggests a preliminary defined
profile with unknown coefficients and the concept of penetration (boundary
layer). The prescribed profile satisfies the boundary conditions imposed by the
boundary layer that allows its coefficients to be expressed through its depth
as unique parameter. The integral approach to the fractional subdiffusion
equation suggests a replacement of the real distribution function by the
approximate profile. The solution was performed with Riemann -Liouville
time-fractional derivative since the integral approach avoids the definition of
the initial value of the time-derivative required by the Laplace transformed
equations and leading to a transition to Caputo derivatives. The method is
demonstrated by solutions to two simple fractional subdiffusion equations
(Dirichlet problems): 1) Time-Fractional Diffusion Equation, and 2)
Time-Fractional Drift Equation, both of them having fundamental solutions
expressed through the M-Write function. The solutions demonstrate some basic
issues of the suggested integral approach, among them: a) Choice of the
profile, b) Integration problem emerging when the distribution (profile) is
replaced by a prescribed one with unknown coefficients; c) Optimization of the
profile in view to minimize the average error of approximations; d) Numerical
results allowing comparisons to the known solutions expressed to the M-Write
function and error estimations.Comment: 15 pages, 7 figures, 3 table
The cauchy problem for the multi-time ractional diffusion equation
In this work, we study the following problem: find a regular solution и = u(x, y
Solution of a multidimensional Abel integral equation of the second kind with partial fractional integrals
Multi-time fractional diffusion equation
We construct a fundamental solution of a multi-time diffusion equation with the Dzhrbashyan-Nersesyan fractional differentiation operator with respect to the time variables. We give a representation for a solution of the Cauchy problem and prove the uniqueness theorem in the class of functions of fast growth. The corresponding results for equations with Riemann-Liouville and Caputo derivatives are obtained as particular cases of the proved assertions