2017
Oct
26

# Landau Lectures: Jean-Michel Bismut (Université Paris-Sud)

Thu, 26/10/2017 (All day) to Mon, 30/10/2017 (All day)

- 2017 Oct 26
# Landau Lectures: Jean-Michel Bismut (Université Paris-Sud)

Thu, 26/10/2017 (All day) to Mon, 30/10/2017 (All day) - 2017 May 18
# Dvoretzky Lectures: Alex Eskin (University of Chicago)

Thu, 18/05/2017 (All day) to Tue, 23/05/2017 (All day) - 2017 May 04
# Erdős Lectures: Jozsef Solymosi (UBC)

Thu, 04/05/2017 (All day) to Wed, 10/05/2017 (All day) - 2017 Mar 02
# Joram Seminar: Discrete holomorphicity in planar statistical physics

## Lecturer:

Hugo Duminil Copin (IHES), Ori Gurel Gurevich (HUJI), Asaf Nachmias (Tel Aviv)Thu, 02/03/2017 (All day) to Sat, 04/03/2017 (All day) - 2017 Jan 09
# Lecture 3: Cohen-Lenstra in the Presence of Roots of Unity

## Lecturer:

Prof. Jacob Tsimerman, University of Toronto4:00pm## Location:

Ross 70(joint with Lipnowski, Sawin) The class group is a natural abelian group one can associated to a number field, and it is natural to ask how it varies in families. Cohen and Lenstra famously proposed a model for families of quadratic fields based on random matrices of large rank, and this was later generalized by Cohen-Martinet. However, their model was observed by Malle to have issues when the base field contains roots of unity. - 2017 Jan 08
# Lecture 2: Torsion In Class Groups

## Lecturer:

Prof. Jacob Tsimerman, University of Toronto12:00pm## Location:

Ross 70A(joint with Bhargava,Shankar,Taniguchi,Thorne, and Zhao) Zhang’s conjecture asserts that for fixed positive integers m, n, the size of the m-torsion in the class group of a degree n number field is smaller than any power of the discriminant. In all but a handful of cases, the best known result towards this conjecture is the ”convex” bound given by the Brauer-Siegel Theorem. We make progress on this conjecture by giving a”subconvex” bound on the size of the 2-torsion of the class group of a number field in terms of its discriminant, for any value of n. - 2017 Jan 05
# Lecture 1: Counting Number Fields

## Lecturer:

Prof. Jacob Tsimerman, University of Toronto2:30pm## Location:

Lecture Hall 2Number fields are fields which are finite extensions of Q. They come with a canonical invariant called the discriminant, which can be thought of as the volume of a certain canonically associated lattice. While these objects are central to modern number theory, it turns out that counting them is extremely difficult. More precisely, what is the asymptotic behavior of N (n,X) the number of degree n field extensions of Q with discriminant at most X as X grows, while n remains fixed? - 2016 Nov 20
# Zabrodsky Lectures: Dan Freed (University of Texas)

Sun, 20/11/2016 (All day) to Thu, 24/11/2016 (All day) - 2016 Jun 15
# Lecture 3: Matroids in permutohedrons in flag varieties

## Lecturer:

Dr. June Huh, IAS & Princeton10:30am## Location:

Rothberg building(s), Room B220I will talk about the three objects and the two inclusions mentioned in the title from a tropical viewpoint. Possible generalizations will be speculated. - 2016 Jun 13
# Lecture 2: Homology and cohomology of tropical varieties

## Lecturer:

Dr. June Huh, IAS & Princeton10:30am## Location:

Rothberg building(s), Room B220A tropical variety is a piecewise linear object that (sometimes) appears as a shadow of an algebraic variety. In this talk, a gentle introduction to the Chow homology and cohomology of tropical varieties will be given. Two family of examples of combinatorial nature will be emphasized: the Stanley-Reisner ring of the boundary of a simplicial polytope, modulo linear system of parameters, and the Chow ring of a matroid.