English

Ill-posedness of a quasilinear wave equation in two dimensions for data in $H^{7/4}$

Analysis of PDEs 2023-08-30 v2

Abstract

In this article, we study the ill-posedness of a quasilinear wave equation. It was shown by Tataru and Smith in 2005 that for any s>7/4s>7/4 (or 11/411/4 in our situation), the equation is well-posed in Hs×Hs1H^{s}\times H^{s-1}. We show a sharpness result by exhibiting a quasilinear wave equation and an initial data such that the Cauchy problem is ill-posed for in H11/4(lnH)β×H7/4(lnHβ)H^{11/4} (\ln H)^{-\beta}\times H^{7/4} (\ln H^{-\beta}).

Keywords

Cite

@article{arxiv.2107.03732,
  title  = {Ill-posedness of a quasilinear wave equation in two dimensions for data in $H^{7/4}$},
  author = {Gaspard Ohlmann},
  journal= {arXiv preprint arXiv:2107.03732},
  year   = {2023}
}