Reducible KAM Tori for the Degasperis-Procesi equation

We develop KAM theory close to an elliptic fixed point for quasi-linear Hamiltonian perturbations of the dispersive Degasperis–Procesi equation on the circle. The overall strategy in KAM theory for quasi-linear PDEs is based on Nash–Moser nonlinear iteration, pseudo differential calculus and normal...

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Detalhes bibliográficos
Autores: Feola, Roberto, Giuliani, Filippo, Procesi, Michela
Tipo de documento: artigo
Data de publicação:2020
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositório:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglês
OAI Identifier:oai:upcommons.upc.edu:2117/332387
Acesso em linha:https://hdl.handle.net/2117/332387
https://dx.doi.org/10.1007/s00220-020-03788-z
Access Level:Acceso aberto
Palavra-chave:Hamiltonian systems
Sistemes hamiltonians
Àrees temàtiques de la UPC::Matemàtiques i estadística
Descrição
Resumo:We develop KAM theory close to an elliptic fixed point for quasi-linear Hamiltonian perturbations of the dispersive Degasperis–Procesi equation on the circle. The overall strategy in KAM theory for quasi-linear PDEs is based on Nash–Moser nonlinear iteration, pseudo differential calculus and normal form techniques. In the present case the complicated symplectic structure, the weak dispersive effects of the linear flow and the presence of strong resonant interactions require a novel set of ideas. The main points are to exploit the integrability of the unperturbed equation, to look for special wave packet solutions and to perform a very careful algebraic analysis of the resonances. Our approach is quite general and can be applied also to other 1d integrable PDEs. We are confident for instance that the same strategy should work for the Camassa–Holm equation.