In this paper, suppose L(t, x, p) = 1 2 A(x)p · p + V (t, x), A is positive definite and symmetric, and both A and V are C 3 and 1-periodic in all of their variables. We prove that the Poincaré map (i.e. the time-1-solution map) of the Lagrangian systempossesses infinitely many periodic points on T n produced by contractible integer periodic solutions.
Main resultsIn this paper, we consider the following Lagrangian systemwhere Lẋ and L x denote the gradients of L with respect toẋ and x respectively. Denote by L(R n ) the set of n × n real matrices. Let N and R be the sets of natural and real numbers respectively. We consider the following conditions on the Lagrangian function L:(L1) L