An Ultra-Weak Space-Time Variational Formulation for the Schr\"odinger Equation
Abstract
We present a well-posed ultra-weak space-time variational formulation for the time-dependent version of the linear Schr\"odinger equation with an instationary Hamiltonian. We prove optimal inf-sup stability and introduce a space-time Petrov-Galerkin discretization with optimal discrete inf-sup stability. We show norm-preservation of the ultra-weak formulation. The inf-sup optimal Petrov-Galerkin discretization is shown to be asymptotically norm-preserving, where the deviation is shown to be in the order of the discretization. In addition, we introduce a Galerkin discretization, which has suboptimal inf-sup stability but exact norm-preservation. Numerical experiments underline the performance of the ultra-weak space-time variational formulation, especially for non-smooth initial data.
Cite
@article{arxiv.2212.14398,
title = {An Ultra-Weak Space-Time Variational Formulation for the Schr\"odinger Equation},
author = {Stefan Hain and Karsten Urban},
journal= {arXiv preprint arXiv:2212.14398},
year = {2023}
}