Homoclinic solutions of Hamiltonian systems with symmetry (Q1818846)

Consider a Hamiltonian system with a Hamiltonian of the following form: \[ H(z,t)=\tfrac{1}{2}Az\cdot z+F(z,t). \] The authors show that if (i) the spectrum of the matrix \(JA\) (where \(J\) is the standard symplectic matrix) does not intersect the imaginary axis; (ii) \(F\) is invariant under the action of a compact Lie group; and (iii) \(F\) is superquadratic at zero and infinity, then the system has infinitely many geometrically distinct homoclinic solutions.