Error estimates of a regularized finite difference method for the Logarithmic Schr\"{o}dinger equation with Dirac delta potential

TL;DR

This paper develops and analyzes a conservative Crank-Nicolson finite difference scheme for the regularized logarithmic Schrödinger equation with Dirac delta potential, achieving second-order accuracy and avoiding numerical blow-up.

Contribution

It introduces a novel finite difference scheme with domain decomposition for the RLSE, providing optimal error estimates and preserving conservation properties.

Findings

Second-order convergence in time and space.

Optimal $H^1$ error estimates established.

Numerical results confirm accuracy and efficiency.

Abstract

In this paper, we introduce a conservative Crank-Nicolson-type finite difference schemes for the regularized logarithmic Schr\"{o}dinger equation (RLSE) with Dirac delta potential in 1D. The regularized logarithmic Schr\"{o}dinger equation with a small regularized parameter $0<\eps \ll 1$ is adopted to approximate the logarithmic Schr\"{o}dinger equation (LSE) with linear convergence rate $O(\eps)$. The numerical method can be used to avoid numerical blow-up and/or to suppress round-off error due to the logarithmic nonlinearity in LSE. Then, by using domain-decomposition technique, we can transform the original problem into an interface problem. Different treatments on the interface conditions lead to different discrete schemes and it turns out that a simple discrete approximation of the Dirac potential coincides with one of the conservative finite difference schemes. The optimal $H^1$ error estimates and the conservative properties of the finite difference schemes are investigated. The Crank-Nicolson finite difference methods enjoy the second-order convergence rate in time and space. Numerical examples are provided to support our analysis and show the accuracy and efficiency of the numerical method.