“…This solution is meant to be compared with equation (30), showing that the second term is a projection of the time evolution into the high-energy state. Notice that the Mathieu functions C a k , − q1 2 , ϕ and S a k , − q1 2 , ϕ already contain in their definition the integral in time of the quasi-energy, as they have the general form e iµ(a k ,−q1/2,ϕ) F(a k , −q 1 /2, ϕ), where F(a k , −q 1 /2, ϕ) is a polynomial and µ(a k , −q 1 /2, ϕ) is the Floquet exponent [35,48]. The small projection of the solution into the high energy state can be seen in figures 3(e) and (f) as an orbital precession due to the two frequencies involved.…”