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Sergei Tabachnikov
Thursday, October 26, 2006
Poncelet porism, old and new: Poncelet grid and the billiard in an ellipse
Sergei Tabachnikov
Pennsylvania State University
Thursday, October 26, 2006
007 Kemeny Hall, 4 pm
Tea 3:30 pm, 223 Kemeny Hall
Abstract: Recently R. Schwartz found an interesting generalization of the classical Poncelet theorem concerning the structure of the so-called Poncelet grid, the set of intersection points of the sides of a polygon inscribed into one conic and circumscribed about another conic. I will discuss the relations of the Poncelet porism with the billiard inside an ellipse and deduce the theorem of Schwartz from complete integrability of the billiard system.
This talk will be accessible to graduate students.
