A second-order correction method for loosely coupled discretizations applied to parabolic-parabolic interface problems

We consider a parabolic-parabolic interface problem and construct a loosely coupled prediction-correction scheme based on the Robin-Robin splitting method analyzed in [J. Numer. Math., 31(1):59–77, 2023]. We show that the errors of the correction step converge at $\mathcal{O}((\mathrm{\Delta }t{)}^2)$, under suitable convergence rate assumptions on the discrete time derivative of the prediction step, where $\mathrm{\Delta }t$ stands for the time-step length. Numerical results are shown to support our analysis and the assumptions.