Odeint to solve Mukhanov equation

[scidam]

If H and ep depend on t you always can do the following:

def H_func(t):
    return ... 

def ep_func(t):
    return ... 

def sol(Y, t, k):
    return [Y[1], -(3-ep_func(t))*Y[1] -((k**2)/H_func(t))*Y[0]]

H_func and ep_func are arbitrary and can include some interpolations as well