For more information about this meeting, contact Victoria Sadovskaya.

Title: | Counting collisions in hard ball gas models and singular geometry of non-positive curvature |

Seminar: | MASS Colloquium |

Speaker: | Dmitri Burago, Penn State University |

Abstract: |

We will discuss a solution to a longâ€“standing problem. The problem itself can be explained
to school kids. Basically, one asks if there exists an N that not more than N elastic collisions
can occur between 10 identical balls before they fly away from each other (no gravity, no
external forces). Of course, there is nothing special about 10, it could be any M and then N=N(M).
The solution is also elementary modulo a few wellâ€“known facts. The problem was that the tools
and facts lie in an area of math which was thought to be very far from the original problem.
We will not get into any technicalities, so the talk should be easily accessible. |

### Room Reservation Information

Room Number: | MB114 |

Date: | 09 / 19 / 2013 |

Time: | 01:25pm - 02:25pm |