Error analysis in unconditionally stable coarsening algorithms

In order to quantitatively study the accuracy of the unconditionally stable coarsening algorithms, we calculate the Fourier space multi step error on the order parameter field by explicitly distinguishing the analytic time $\tau$ and the algorithmic time $t$. The calculation determines the error in the order parameter and the scaled correlations. This error contributes a correction term in the analytic time step, which is crucial in understanding the accuracy in unconditionally stable coarsening algorithms.