**September 20**: Ryan Solava

**Title**: How Many Crayons? (Graph) Coloring Problems

**Abstract**: A question that you might (or might not) ask is how many different colors of crayons do you need so that for any page of a coloring book, you can color each region, so that no two adjacent regions have the same color. This question is more commonly phrased in terms of maps, and the answer is given by an important theorem, which I won’t name here because the name gives away the answer. In this talk, we will explore this problem and the more general topic of graph coloring. Together we will get a glimpse of discrete mathematics and combinatorics, a side of math that you don’t often get to see in required math courses.

**September 27**: Alex Vlasiuk

**Title**: The twisted nature of polyominoes

**Abstract**: Polyominoes are flat geometric figures obtained by joining several equal squares edge to edge. They can tile the plane, help you play Tetris or Blokus, serve as a literary subject* or a test case for your programming/counting skills, or simply be the building blocks of many a joyous pastime.

But for all that flatness, there’s a certain twist to them.

* S. W. Golomb, Polyominoes, Princeton University Press; 2nd edition 1996, ISBN 0-691-02444-8

**October 4**: Sandeepan Parekh

**Title**: Patterns in the Pascal’s triangle

**Abstract**: Pascal’s triangle is a triangular array of numbers made from a very simple rule. However, all sorts of interesting patterns crop up in this innocent looking triangle, from Fibonacci numbers to fractals. You can even find the constants e and pi. In this talk, we’ll try and explore various nooks and crannies of this fascinating object.

**October 11**: Chang-Hsin Lee

**Title**: Bayes-running in baseball

**Abstract**: Is 4/10 greater than 300/1000? It may be a silly question to your Calculus teacher, but not so much to a sports fan when the numbers are associated to the players. Is a .400 hitter really better than a .300 hitter in baseball? How do we estimate the proportion of success when there is a lack of evidence? In this talk, I will show you one way to attack this problem using empirical Bayes estimation. The stage will be set in the baseball world but no coding or baseball knowledge is required.

**October 18**: José Gil-Ferez

**Title**: Rainbows

**Abstract**: Rainbows are these colorful arrangements of light that appear in the sky, sometimes, after the rain; marvelous phenomena that make everyone’s heart happier. Noticed since antiquity, they have entered our cultures and are very present as symbols of beauty, peace, covenants with the gods, human rights, technology, … We will take a closer look, from a Mathematical perspective, to these gorgeous shows that Nature puts out there only for your eyes.

**October 25**: Matthieu Jacquemet

**Title**: Geometries

**Abstract**: What is the shortest path between two points? This seemingly

obvious question depends in fact quite strongly on what we mean by

‘shortest’. In this talk, we shall give an introduction to the notion of

distance, see some examples of non-usual distances, and finally give an

introduction to so-called non-Euclidean geometries.

**November 1**: Krishnendu Khan

**Title**: Geometry of Surfaces

**Abstract**: What is a surface? How can we distinguish different surfaces from each other? What kind of formal structures do we need to do that?

**November 8**: Zach Gaslowitz

**Title**: The Trouble with Voting

**Abstract**: After you cast your vote this election, come explore some of the (mathematical) challenges that one runs into when trying to turn a pile of ballots into a single winner. How do we decide who should win? How does this question influence our democracy as a whole?