# Mathematics Colloquium

#### Thursday, February 15, 1996, 4:00pm

#### 102 Bradley Hall

## Professor Bob Brooks

#### University of Southern California

speaks on
### Platonic Surfaces and Graphs

**Abstract.** We will consider a family of graphs and surfaces which are naturalgeneralizations of the classical Platonic solids. We will show that these surfaces and graphs have the "expander property," which is important in theoretical computer science. This result is also related to the Selberg 3/16 Theorem of number theory.
**Tea. ** High tea will be served at 3:30pm in the Lounge.

**Emmy's. ** Certain refreshments will be available at the Emmy's after the talk.

**Hostess. ** Carolyn Gordon is the hostess. Anybody who is interested in having dinner with the speaker should contact Carolyn at 646-3047.