### Monday, Oct. 12

**No classes – Fall Break **

### Tuesday, Oct. 13

**No Classes – Fall Break **

### Wednesday, Oct. 14

**No Seminars**

### Thursday, Oct. 15

**Chemistry Seminar: “ Watching energy dance in plastic solar cells”**Dr. David Blank, University of Minnesota

3:00 p.m. refreshments, seminar will start at 3:15 p.m.

### Friday, Oct. 16

**MSCS Research Seminar**: *The combinatorics of q-analogues**
*Joel Lewis is a National Science Foundation postdoctoral fellow at the University of Minnesota.

*Often, a combinatorial question involving permutations may be phrased naturally in terms of permutations matrices. In this case, it is sometimes possible to phrase the same question in other contexts; in particular, for invertible matrices over a finite field having q elements. In many situations, these two questions are related in the following very surprising way: the limit as q tends to 1 of the answer about matrices over finite fields is equal to the answer of the original question about permutations. In this talk, I will discuss examples of this phenomenon of “q-analogues” that come from the part of combinatorics known as rook theory. The only prerequisites for this talk are familiarity with linear algebra and the concept of a field.*

3:30 p.m., RNS 204