Spring 2013 titles / abstracts

January 28

Speaker: Daniel Miller, Cornell University

Title: Taniyama-Shimura, the $R=T$ theorem and Fermat-Wiles

Abstract: I will explain the statement of the Taniyama-Shimura conjecture, discuss Galois representations, deformation theory and the $R=T$ theorem, and explain how Taniyama-Shimura implies Fermat's Last Theorem. I will not assume the audience knows anything about these topics.

February 4

Speaker: Christine McMeekin, Cornell University

Title: The average rank of elliptic curves

Abstract: I will discuss the results of Manjul Bhargava and Arul Shankar regarding the average rank of elliptic curves. I will not be proving these results, but will introduce necessary terminology to understand their statements and will discuss some history and the importance of these results.

February 11

Speaker: Theodore Hui, Cornell University

Title: Distribution of the partition function modulo $m$.

Abstract: Let $p(n)$ be the partition function. Ramanujan discovered the identities $p(5 n+4)\equiv 0\pmod 5$, $p(7 n+5)\equiv 0\pmod 7$ and $p(11 n+6)\equiv 0\pmod{11}$. However, little was known for larger primes. Erdös conjectured that there are infinitely many primes $m$ such that $p(n_m)\equiv 0\pmod m$ for some $n_m$. In 2000, Ken Ono completely settled the problem by considering a special sequence of generating functions. I will present the terminology he uses and outline his proof. I will then focus on how to use those generating functions to both prove the periodicity of $p(n)$ modulo $m$ and generate some interesting congruences.

February 18

Speaker: Ling Long, Iowa State University and Cornell University

Title: Weakly holomorphic modular forms and congruences

Abstract: We will discuss a recent preprint by Kazalicki and Scholl on Hecke-like congruences satisfied by weakly holomorphic modular forms (allowing poles at cusps). Unlike the case of original congruences for cusp form, these congruences are nontrivial even for congruence subgroups.

February 25

Speaker: Ravi Ramakrishna, Cornell University

Title: A gentle introduction to $p$-adic Local Langlands, part I

Abstract: You may have run into expressions like "the Langlands program" or "the local Langlands program" or "the $p$-adic Local Langlands program." In this talk I will ignore the first expression but try to give some sense of what the latter two expressions mean by tying them to something more familiar, local class field theory.

March 4

Speaker: Joel Dodge, Binghamton University

Title: An introduction to the Carlitz module and explicit class field theory for $\mathbb{F}_q(T)$

Abstract: The study of the Carlitz module can be used to provide an explicit class field theory for the rational function field $k=\mathbb{F}_q(T)$ in the sense that: (1) it provides an explicit collection of polynomials whose roots generate the maximal abelian extension of $k$ and (2) it gives an explicit description of the action of the galois group of $k^{ab}/k$ on the roots of these polynomials. This is in perfect analogy with the construction of the maximal abelian extension of $\mathbb{Q}$ via the cyclotomic fields. I will introduce the basic notions of the Carlitz module and state many of the basic theorems of the subject. This will already go a long way towards developing the analogy between extensions of $k$ built from the Carlitz moduel and the cyclotomic extensions of $\mathbb{Q}$. In the end, I will state the analog of the Kronecker-Weber theorem for $k$.

March 11

Speaker: Ravi Ramakrishna, Cornell University

Title: A gentle introduction to $p$-adic Local Langlands, part II

March 18

Spring break

March 25

Speaker: Ravi Ramakrishna, Cornell University

Title: A gentle introduction to $p$-adic Local Langlands, part III

April 1

No seminar

April 8

Speaker: Daniel Vallieres, Binghamton University

Title: The abelian Stark conjecture

Abstract: Harold Stark wrote a series of four papers in the 70s where he pioneered the study of the special value $s=0$ of Artin $L$-functions. In this talk, we will try to give some of Stark's insights. It will be a gentle introduction to the abelian rank one Stark conjecture.

April 15

Speaker: Ravi Ramakrishna, Cornell University

Title: A gentle introduction to $p$-adic Local Langlands, part IV

April 22

Speaker: Daniel Miller, Cornell University

Title: Towards perfectoid spaces

Abstract: Recently Peter Scholze was able to prove a wide range of special cases of Deligne's weight monodromy conjecture by introducing a class of spaces he called perfectoid spaces. The theory of perfectoid spaces is quite complicated, so I will not say much about it. Instead, I will explain some of the motivation behind Scholze's work. In particular, I will discuss a beautiful result of Fontaine and Wintenberger relating the Galois groups of certain fields in characteristic $p$ and characteristic zero.

April 29

Seminar cancelled

May 6

Speaker: Everyone

Title: Summaries of the Upstate New York Number Theory Conference.

Abstract: Everyone will be giving summaries / additional thoughts on the topics spoken on at the Upstate Number Theory Conference.