# AMS Student Chapter Seminar

The AMS Student Chapter Seminar is an informal, graduate student-run seminar on a wide range of mathematical topics. Pastries (usually donuts) will be provided.

**When:**Wednesdays, 3:00 PM – 3:30 PM**Where:**Van Vleck, 9th floor lounge (unless otherwise announced)**Organizers:**Daniel Hast, Ryan Julian, Cullen McDonald, Zachary Charles

Everyone is welcome to give a talk. To sign up, please contact one of the organizers with a title and abstract. Talks are 30 minutes long and should avoid assuming significant mathematical background beyond first-year graduate courses.

The schedule of talks from past semesters can be found here.

## Spring 2017

### January 25, Brandon Alberts

Title: Ultraproducts - they aren't just for logicians

Abstract: If any of you have attended a logic talk (or one of Ivan's donut seminar talks) you may have learned about ultraproducts as a weird way to mash sets together to get bigger sets in a nice way. Something particularly useful to set theorists, but maybe not so obviously useful to the rest of us. I will give an accessible introduction to ultraproducts and motivate their use in other areas of mathematics.

### February 1, Megan Maguire

Title: Hyperbolic crochet workshop

Abstract: TBA

### February 8, Cullen McDonald

### February 15, Paul Tveite

Title: Fun with Hamel Bases!

Abstract: If we view the real numbers as a vector field over the rationals, then of course they have a basis (assuming the AOC). This is called a Hamel basis and allows us to do some cool things. Among other things, we will define two periodic functions that sum to the identity function.

### February 22, Wil Cocke

Title: Practical Graph Isomorphism

Abstract: Some graphs are different and some graphs are the same. Sometimes graphs differ only in name. When you give me a graph, you've picked an order. But, is it the same graph across every border?

### March 1, Megan Maguire

Title: I stole this talk from Jordan.

Abstract: Stability is cool! And sometimes things we think don't have stability secretly do. This is an abridged version of a very cool talk I've seen Jordan give a couple times. All credit goes to him. Man, I should have stolen his abstract too.

### March 7, Liban Mohamed

Title: Strichartz Estimates from Qualitative to Quantitative

Abstract: Strichartz estimates are inequalities that give one way understand the decay of solutions to dispersive PDEs. This talk is an attempt to reconcile the formal statements with physical intuition.

### March 15, Zachary Charles

Title: Netflix Problem and Chill

Abstract: How are machine learning, matrix analysis, and Napoleon Dynamite related? Come find out!

### April 5, Vlad Matei

### April 12, Micky Steinberg

Title: Groups as metric spaces

Abstract: Given a group as a set of generators and relations, we can define the “word metric” on the group as the length of the shortest word “between” two elements. This isn’t well-defined, since different generating sets give different metrics, but it is well-defined up to “quasi-isometry”. Come find out what we can do with this! There will lots of pictures and hand-waving!

### April 19, Solly Parenti

Title: Elementary Integration

Abstract: Are you like me? Have you also told your calculus students that finding the antiderivative of e^(-x^2) is impossible? Do you also only have a slight idea about how to prove it? Come find out more about the proof and free yourself of that guilt.

### April 26, Ben Bruce

Title: Permutation models

Abstract: Permutation models belong to a version of axiomatic set theory known as "set theory with atoms." I will give some examples of permutation models and highlight their connection to the axiom of choice and notions of infinity. There will be concrete examples, and no prior knowledge of set theory is required.

### May 3, Iván Ongay-Valverde

Title: Living with countably many reals?

Abstract: Can I make you believe that a countable set of reals are all the reals? If we just have countably many reals, what happens with the others? Do they have any special properties? Let's play a little with our notion of 'reality' and allow to ourselves to find crazy reals doing weird things. Hopefully, no-one's headache will last forever.