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arXiv · 1807.02455

On the non-existence of local Birkhoff coordinates for the focusing NLS equation

T. Kappeler·P. Topalov
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Abstract

We prove that there exist potentials so that near them the focusing non-linear Schr\"odinger equation does not admit local Birkhoff coordinates. The proof is based on the construction of a local normal form of the linearization of the equation at such potentials.

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T. Kappeler, P. Topalov. 2018-07-06. On the non-existence of local Birkhoff coordinates for the focusing NLS equation. https://arxiv.org/abs/1807.02455

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