Core Concepts
Arbitrarily high-order rescaled exponential time differencing Runge-Kutta (ETDRK) schemes are developed that unconditionally preserve the maximum bound principle and the original energy dissipation law for the Allen-Cahn equation.
Abstract
The key contributions of this work are:
A class of arbitrarily high-order ETDRK schemes are introduced that preserve the original energy dissipation law under a certain time step size restriction.
A rescaling technique is proposed to modify the interpolation polynomial in the ETDRK schemes, which ensures the unconditional preservation of the maximum bound principle (MBP).
The rescaled ETDRK schemes maintain the original energy dissipation law under a small time step constraint, without requiring the Lipschitz continuity assumption on the nonlinear term.
Rigorous convergence analysis is provided for the proposed arbitrarily high-order rescaled ETDRK schemes.
The authors first prove that the original energy dissipation law is preserved by the standard ETDRK schemes under a certain time step size restriction, assuming the nonlinearity is Lipschitz continuous. To relax this assumption, they then introduce a rescaling technique that adjusts the interpolation polynomial slightly without compromising the convergence order. This rescaled ETDRK scheme is shown to unconditionally preserve the MBP and the original energy dissipation law under a small time step constraint. The theoretical results are validated through numerical experiments.