A Symmetric Normal Form for the Fermi Pasta Ulam Chain
نویسنده
چکیده
The Fermi Pasta Ulam chain with periodic boundary conditions admits discrete and continuous symmetries. These symmetries allow one to formulate important restrictions on the Birkhoff normal form of this Hamiltonian system. We derive integrability properties and KAM statements. Hence the combination of symmetry and resonance in the periodic Fermi Pasta Ulam chain explains its quasiperiodic behaviour. This article contains a summary of the results obtained in references 11 and 12
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