### Pentagrama Myrificum, old wine into new wineskins

- Series
- School of Mathematics Colloquium
- Time
- Thursday, February 4, 2010 - 11:05 for 1 hour (actually 50 minutes)
- Location
- Skiles 269
- Speaker
- Sergei Tabachnikov – Penn State University

**Please Note:** Refreshments at 4PM in Skiles 236

The Pentagram map is a projectively natural iteration on
plane polygons. Computer experiments show that the Pentagram map has
quasi-periodic behavior. I shall explain that the Pentagram map is a
completely integrable system whose continuous limit is the Boussinesq
equation, a well known integrable system of soliton type. As a
by-product, I shall demonstrate new configuration theorems of
classical projective geometry.