English

Notes on tangent bicharacteristics and ill-posedness of the Cauchy problem

Analysis of PDEs 2025-06-12 v2 Dynamical Systems

Abstract

We exhibit a family of second-order hyperbolic differential operators presenting spectral transition of the Hamilton map. As a consequence we prove that the Cauchy problem is not locally solvable at the origin in Gevrey classes of order greater than some fixed value. The main feature of these operators is that they may all have bicharacteristics tangent to the double manifold.

Keywords

Cite

@article{arxiv.2506.08481,
  title  = {Notes on tangent bicharacteristics and ill-posedness of the Cauchy problem},
  author = {Enrico Bernardi and Tatsuo Nishitani},
  journal= {arXiv preprint arXiv:2506.08481},
  year   = {2025}
}