A modified quasi-boundary value method for the backward time-fractional diffusion problem
School of Mathematics and Statistics, Lanzhou University, P.R. China
Received: 30 November 2012
Revised: 25 July 2013
In this paper, we consider a backward problem for a time-fractional diffusion equation with variable coefficients in a general bounded domain. That is to determine the initial data from a noisy final data. Based on a series expression of the solution, a conditional stability for the initial data is given. Further, we propose a modified quasi-boundary value regularization method to deal with the backward problem and obtain two kinds of convergence rates by using an a priori regularization parameter choice rule and an a posteriori regularization parameter choice rule. Numerical examples in one-dimensional and two-dimensional cases are provided to show the effectiveness of the proposed methods.
Mathematics Subject Classification: 35R11 / 35R30
Key words: Backward problem / fractional diffusion equation / modified quasi-boundary value method / convergence analysis / a priori parameter choice / morozov’s discrepancy principle
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