English

Instability for standing waves of nonlinear Klein-Gordon equations via mountain-pass arguments

Analysis of PDEs 2012-09-14 v1

Abstract

We introduce mountain-pass type arguments in the context of orbital instability for Klein-Gordon equations. Our aim is to illustrate on two examples how these arguments can be useful to simplify proofs and derive new results of orbital stability/instability. For a power-type nonlinearity, we prove that the ground states of the associated stationary equation are minimizers of the functional "action" on a wide variety of constraints. For a general nonlinearity, we extend to the dimension N=2 the classical instability result for stationary solutions of nonlinear Klein-Gordon equations proved in 1985 by Shatah in dimension N>2.

Keywords

Cite

@article{arxiv.0710.5583,
  title  = {Instability for standing waves of nonlinear Klein-Gordon equations via mountain-pass arguments},
  author = {Louis Jeanjean and Stefan Le Coz},
  journal= {arXiv preprint arXiv:0710.5583},
  year   = {2012}
}