141 research outputs found
Invariant manifolds around soliton manifolds for the nonlinear Klein-Gordon equation
We construct center-stable and center-unstable manifolds, as well as stable
and unstable manifolds, for the nonlinear Klein-Gordon equation with a focusing
energy sub-critical nonlinearity, associated with a family of solitary waves
which is generated from any radial stationary solution by the action of all
Lorentz transforms and spatial translations. The construction is based on the
graph transform (or Hadamard) approach, which requires less spectral
information on the linearized operator, and less decay of the nonlinearity,
than the Lyapunov-Perron method employed previously in this context. The only
assumption on the stationary solution is that the kernel of the linearized
operator is spanned by its spatial derivatives, which is known to hold for the
ground states. The main novelty of this paper lies with the fact that the graph
transform method is carried out in the presence of modulation parameters
corresponding to the symmetries.Comment: 38 page
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