2022/12/31 by Du, Jiayin, Ji, Shuguan, Li, Yong
#Dynamical Systems (math.DS) #FOS: Mathematics
paper · doi:10.48550/arxiv.2301.00206
In this paper, we study the Melnikov's persistence for completely degenerate Hamiltonian systems with the following Hamiltonian H(x,y,u,v)=h(y)+g(u,v)+ε P(x,y,u,v),~~~(x,y,u,v)∈ \mathbbTn×G× ℝd× ℝd, where n≥2 and d≥1 are positive integers, G⊂ℝn, g=o(|u|2+|v|2) admits complete degeneracy and certain transversality, and ε P is the small perturbation. This is a try in studying lower-dimensional invariant tori in the normal complete degeneracy. Under Rüssmann-like non-degenerate condition and transversality condition, we apply the homotopy invariance of topological degree to remove the first order terms about u and v and employ the quasi-linear KAM iterative procedure to derive the persistence of lower-dimensional invariant tori.