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arXiv · 2109.02187

On solutions with compact spectrum to nonlinear Klein--Gordon and Schroedinger equations

Andrew Comech
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Abstract

We consider finite energy solutions to the nonlinear Schroedinger equation and nonlinear Klein--Gordon equation and find the condition on the nonlinearity so that the standard, one-frequency solitary waves are the only solutions with compact spectrum. We also construct an example of a four-frequency solitary wave solution to the nonlinear Dirac equation in three dimensions.

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Andrew Comech. 2021-09-05. On solutions with compact spectrum to nonlinear Klein--Gordon and Schroedinger equations. https://arxiv.org/abs/2109.02187

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