**Milena Radnovic**

Mathematics Inst. SANU, Serbia

October 11, 2012

**Poncelet porism and elliptical billiards**:
Suppose that two conics are given in the plane, together with a closed polygonal line inscribed in one of them and circumscribed about the other one. Then, Poncelet porism states that infinitely many
such closed polygonal lines exist - every point of the first conic is a vertex of such a polygon. In the talk, the most important results and ideas around Poncelet porism, both classical and modern,
together with their historical origins and natural generalizations will be presented. We will particularly pay attention to applications in billiard dynamics including higher-dimesional cases.