Pure and Applied Mathematics Quarterly

Volume 20 (2024)

Number 4

Semi-global controllability of a geometric wave equation

Pages: 1763 – 1824

DOI: https://dx.doi.org/10.4310/PAMQ.2024.v20.n4.a9

Authors

Joachim Krieger (Bâtiment des Mathématiques, EPFL, Lausanne, Switzerland)

Shengquan Xiang (School of Mathematical Sciences, Peking University, Beijing, China)

Abstract

We prove the semi-global controllability and stabilization of the $(1 + 1)$-dimensional wave maps equation with spatial domain $\mathbb{S}^1$ and target $\mathbb{S}^k$. First, we show that damping stabilizes the system when the energy is strictly below the threshold $2\pi$, where harmonic maps appear as obstruction for global stabilization. Then, we adapt an iterative control procedure to get low-energy exact controllability of the wave maps equation. This result is optimal in the case $k = 1$.

Keywords

Wave maps, semi-global controllability, quantitative stabilization

2010 Mathematics Subject Classification

Primary 35B40, 35L05. Secondary 93C20.

The full text of this article is unavailable through your IP address: 172.17.0.1

Dedicated to Demetrios Christodoulou for his 70th birthday, in friendship and admiration

Received 17 February 2022

Received revised 18 August 2022

Accepted 24 September 2022

Published 18 July 2024