KAM for Hamiltonian partial differential equations with weaker Spectral Asymptotics

Yong Li, Lu Xu

In this paper, we establish an abstract infinite dimensional KAM theorem dealing with normal frequencies in weaker spectral asymptotics Ω_{i}(ξ)=i^d+o(i^{d})+o(i^δ), where $d>0, δ<…