We implement the Numerical Unified Transform Method to solve the Nonlinear Schr\"odinger equation on the half-line. For so-called linearizable boundary conditions, the method solves the half-line problems with comparable complexity as the Numerical Inverse Scattering Transform solves whole-line problems. In particular, the method computes the solution at any $x$ and $t$ without spatial discretization or time stepping. Contour deformations based on the method of nonlinear steepest descent are used so that the method's computational cost does not increase for large $x,t$ and the method is more accurate as $x,t$ increase. Our ideas also apply to some cases where the boundary conditions are not linearizable.
翻译:我们用数字统一变换法在半线上解决非线性Schr\'odinger等式。对于所谓的可线性边界条件,该方法解决了类似复杂程度的半线问题,因为数字反向分流变换法解决了整线问题。特别是,该方法在没有空间分化或时间阶梯的情况下以任何美元和美元计算解决办法。使用了基于非线性最陡度下行方法的孔径变形,这样,该方法的计算成本不会增加大的美元,t$的计算成本不会增加,而该方法的精确度是增加美元,t$。我们的想法也适用于边界条件无法线性化的一些情况。