“…Such a system is called an elliptical billiards. The notion of billiard system was introduced by Birkhoff in [10], and since then it became a challenging research field, which has attracted the attention of researchers from mathematics, engineering and physics, where billiards are used to investigate the transition from quantum mechanics to classical mechanics (see, e.g., [11]). A lot of work has been done to study the properties of trajectories followed by a free particle on billiards of different shape and dimension, that is when no control is exerted on the moving mass (see, e.g., [12]).…”