On the relation between Galerkin approximations and canonical best-approximations of solutions to some non-linear Schrödinger equations

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Hassan, Muhammad, Maday, Yvon, Wang, Yipeng
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929710384021504
author Hassan, Muhammad
Maday, Yvon
Wang, Yipeng
author_facet Hassan, Muhammad
Maday, Yvon
Wang, Yipeng
contents In this paper, we establish a superconvergence property of Galerkin approximations to some non-linear Schrödinger equations of Gross-Pitaevskii type. More precisely, denoting by $u^*\in X \subseteq H^1(Ω)$ the exact solution to such an equation, by $\{X_δ\}_{δ>0}$, a sequence of conforming subspaces of $X$ satisfying the approximation property, by $u_δ^*\in X_δ$ the Galerkin solution to the equation, and by $Π^X_δ u^*$, the $(\cdot, \cdot)_{X}$-best approximation in $X_δ$ of $u^*$, we show -- under some assumptions -- that $u_δ^*$ converges at a higher rate to $Π^X_δ u^*$ than to $u^*$ in both the $L^2$ norm and the canonical $H^1$ norm. Our results apply to conforming finite element discretisations as well as spectral Galerkin methods based on polynomials or Fourier (plane-wave) expansions.
format Preprint
id arxiv_https___arxiv_org_abs_2502_07638
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the relation between Galerkin approximations and canonical best-approximations of solutions to some non-linear Schrödinger equations
Hassan, Muhammad
Maday, Yvon
Wang, Yipeng
Numerical Analysis
65N15, 65N25, 65N30, 65N35
In this paper, we establish a superconvergence property of Galerkin approximations to some non-linear Schrödinger equations of Gross-Pitaevskii type. More precisely, denoting by $u^*\in X \subseteq H^1(Ω)$ the exact solution to such an equation, by $\{X_δ\}_{δ>0}$, a sequence of conforming subspaces of $X$ satisfying the approximation property, by $u_δ^*\in X_δ$ the Galerkin solution to the equation, and by $Π^X_δ u^*$, the $(\cdot, \cdot)_{X}$-best approximation in $X_δ$ of $u^*$, we show -- under some assumptions -- that $u_δ^*$ converges at a higher rate to $Π^X_δ u^*$ than to $u^*$ in both the $L^2$ norm and the canonical $H^1$ norm. Our results apply to conforming finite element discretisations as well as spectral Galerkin methods based on polynomials or Fourier (plane-wave) expansions.
title On the relation between Galerkin approximations and canonical best-approximations of solutions to some non-linear Schrödinger equations
topic Numerical Analysis
65N15, 65N25, 65N30, 65N35
url https://arxiv.org/abs/2502.07638