English

Counterexamples to $ C^{\infty} $ well posedness for some hyperbolic operators with triple characteristics

Analysis of PDEs 2014-05-14 v1

Abstract

In this paper we prove that for a class of non-effectively hyperbolic operators with smooth triple characteristics the Cauchy problem is well posed in the Gevrey 2 class, beyond the generic Gevrey class 3/2 3/2 (see e.g. \cite{Bro}). Moreover we show that this value is optimal.

Cite

@article{arxiv.1405.3052,
  title  = {Counterexamples to $ C^{\infty} $ well posedness for some hyperbolic operators with triple characteristics},
  author = {Enrico Bernardi and Tatsuo Nishitani},
  journal= {arXiv preprint arXiv:1405.3052},
  year   = {2014}
}
R2 v1 2026-06-22T04:12:41.289Z