“…Moreover, there are certain classes of more realistic models which share specific properties of maps such as being low-dimensional and exhibiting certain periodicities. Indeed, theoretical investigations of chaotic billiards subject to external fields [27], of periodic Lorentz gases [28,29], and of pendulum-like differential equations [30,31,32,33,34,35,36] showed that many properties of deterministic transport in maps carry over to these more complex chaotic dynamical systems.…”