### Upcoming Event

**Friday, October 19 4-5 pm in 115 Avery Hall: 12-th annual Pi Mu Epsilon Lecture**

Presented by professor Robert Ghrist - Andrea Mitchell university professor at the University of Pennsylvania.

### Previous Event

**Thursday, September 13, 5-6 pm in 351 Avery Hall:**

*Building spheres using puzzle pieces*Presentation by professor Alex Zupan.

Topologists like to break up complicated objects into small, manageable pieces. As a simple example, a natural way to split the surface of the earth is to divide it into two pieces, the Northern and Southern Hemispheres. Of course, the earth's surface can also be cut into many more components, and a natural question is to determine how each of these decompositions is related to any other. We consider the problem of cutting up a sphere into topological puzzle pieces in dimension two, three, and four, describing some recent progress (joint with Jeffrey Meier) on a big, unsolved problem in this area.

### About Math Club

The Math Club is an umbrella organization for mathematics-related activities open to all UNL students. The Math Club sponsors events throughout the academic year in association with the Nebraska Alpha Chapter of Pi Mu Epsilon and the Women Undergraduates in Mathematics at Nebraska.

**Subscribe** to the Math Club mailing list. Use **math-club** for the list name.

### Pi Mu Epsilon (ΠΜΕ)

Pi Mu Epsilon is a national mathematics honor society that promotes scholarly activity in mathematics among students in academic institutions. UNL's Nebraska Alpha Chapter, founded in 1928, was the 15th chapter out of over 350 chapters around the country.

Learn more about joining Pi Mu Epsilon.

#### Faculty Advisors

Try the

**UNL Math Challenge**

New problems are posted on the website above every other week.

Try it for fun, intellectual exercise, and a chance to win a

Gift Card to Dunkin Donuts!