TY - JOUR T1 - Finite Difference Methods for the Heat Equation with a Nonlocal Boundary Condition AU - Thomée , V. AU - Vasudeva Murthy , A.S. JO - Journal of Computational Mathematics VL - 1 SP - 17 EP - 32 PY - 2015 DA - 2015/02 SN - 33 DO - http://doi.org/10.4208/jcm.1406-m4443 UR - https://global-sci.org/intro/article_detail/jcm/9825.html KW - Heat equation, Artificial boundary conditions, unbounded domains, product quadrature. AB -

We consider the numerical solution by finite difference methods of the heat equation in one space dimension, with a nonlocal integral boundary condition, resulting from the truncation to a finite interval of the problem on a semi-infinite interval. We first analyze the forward Euler method, and then the $θ$-method for $0 < θ ≤ 1$, in both cases in maximum-norm, showing $O(h^2 + k)$ error bounds, where $h$ is the mesh-width and $k$ the time step. We then give an alternative analysis for the case $θ = 1/2$, the Crank-Nicolson method, using energy arguments, yielding a $O(h^2$ + $k^{3/2}$) error bound. Special attention is given the approximation of the boundary integral operator. Our results are illustrated by numerical examples.