2019 May 19

# The 22nd Midrasha Mathematicae : Equidistribution, Invariant Measures and Applications

Sun, 19/05/2019 (All day) to Fri, 24/05/2019 (All day)

## Location:

Israel Institute for Advanced Studies, The Hebrew University of Jerusalem

## A tribute to the Legacy of Marina Ratner

For more information and registration click here.

2018 Oct 18

# Zabrodsky Lectures: Prof. Rahul Pandharipande (ETH Zurich)

Thu, 18/10/2018 (All day) to Mon, 22/10/2018 (All day)

2018 Oct 22

# Zabrodsky Lecture 3: CohFT calculations

## Lecturer:

Rahul Pandharipande (ETH Zurich)
2:00pm to 3:00pm

## Location:

Ross 70

I will explain how calculations of various natural classes on the moduli of curves fit into the CohFT framework. These include calculations related to Hilbert schemes of points, Verlinde bundles, and, if time permits, double ramification (DR) cycles.

2018 Oct 21

# Zabrodsky Lecture 2: Cohomological Field Theories

## Lecturer:

Rahul Pandharipande (ETH Zurich)
11:00am to 12:00pm

## Location:

Ross 70
Cohomological Field Theories (CohFTs) were introduced to keep track of the classes on the moduli spaces of curves defined by Gromov-Witten theories and their cousins. I will define CohFTs (following Kontsevich-Manin), explain the classification in the semisimple case of Givental-Teleman, and discuss the application to Pixton's relations which appear in the first lecture.
2018 Oct 18

# Zabrodsky Lecture 1: Geometry of the moduli space of curves

## Lecturer:

Rahul Pandharipande (ETH Zurich)
2:30pm to 3:30pm

## Location:

Manchester House, Lecture Hall 2

The moduli space of curves, first appearing in the work of Riemann in the 19th century, plays an important role in geometry. After an introduction to the moduli space, I will discuss recent directions in the study of tautological classes on the moduli space following ideas and conjectures of Mumford, Faber-Zagier, and Pixton. Cohomological Field Theories (CohFTs) play an important role. The talk is about the search for a cohomology calculus for the moduli space of curves parallel to what is known for better understood geometries. My goal is to give a presentation of the progress in the past decade and the current state of the field.

2018 Oct 07

# The 4th Israeli Workshop for Women in Mathematics @ Sde Boker

Sun, 07/10/2018 (All day) to Thu, 11/10/2018 (All day)

## Location:

Sde Boker

The 4th Israeli Workshop for Women in Mathematics will be held in Sde Boker on between October 7th and October 11th.
For more information and registration click here.

2019 Mar 11

# Combinatorics Seminar: Yuval Filmus (Technion) "Structure of (almost) low-degree Boolean functions"

11:00am to 1:00pm

## Location:

CS bldg, room B500, Safra campus, Givat Ram
Speaker: Yuval Filmus, Technion
Title: Structure of (almost) low-degree Boolean functions
Abstract:
Boolean function analysis studies (mostly) Boolean functions on {0,1}^n.
Two basic concepts in the field are *degree* and *junta*.
A function has degree d if it can be written as a degree d polynomial.
A function is a d-junta if it depends on d coordinates.
Clearly, a d-junta has degree d.
What about the converse (for Boolean functions)?
What if the Boolean function is only *close* to degree d?
2018 Oct 23

# Dynamics Lunch: Amir Algom "On \alpha \beta sets."

12:00pm to 1:00pm

## Location:

Manchester faculty club

2019 Jan 15

# Dynamics Lunch: Tsviqa Lakrec "Recurrence properties of random walks on ﬁnite volume homogeneous manifold"

12:00pm to 1:00pm

2019 Jan 10

# Joram Seminar: Larry Guth (MIT) - Introduction to decoupling

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem
Decoupling is a recent development in Fourier analysis. In the late 90s, Tom Wolff proposed a decoupling conjecture and made the first progress on it. The full conjecture had seemed well out of reach until a breakthrough by Jean Bourgain and Ciprian Demeter about five years ago.
Decoupling has applications to problems in PDE and also to analytic number theory. One application involves exponential sums, sums of the form
$$\sum_j e^{2 pi i \omega_j x}.$$
2018 Jun 28

# Basic Notions: Barry Simon "More Tales of our Forefathers (Part II)"

4:00pm to 5:30pm

## Location:

Manchester Hall 2
This is not a mathematics talk but it is a talk for mathematicians. Too often, we think of historical mathematicians as only names assigned to theorems. With vignettes and anecdotes, I'll convince you they were also human beings and that, as the Chinese say, "May you live in interesting times" really is a curse. Among the mathematicians with vignettes are Riemann, Newton, Poincare, von Neumann, Kato, Loewner, Krein and Noether.
2018 Jun 27

# Eshnav: Dr. Shaul Zemel : "From sequences of numbers to Fermat's last theorem"

Dr. Shaul Zemel
6:00pm to 7:15pm

## Location:

Manchester House, Lecture Hall 2

ד"ר שאול זמל : מסדרות מספרים ועד המשפט האחרון של פרמה

אחת הדרכים להבין התנהגויות של סדרות מספרים היא לנתח את הפונקציה היוצרת שלהם. זה מועיל במיוחד במקרה שהפונקציה הזאת נמצאת במרחב וקטורי ממימד סופי קטן. נדגים זאת במקרה פשוט, ואז נתאר סדרות מספרים המתקבלות מתבניות מודולריות.
נראה איך מקבלים מכך כמה יחסים מעניינים, ונסיים בתיאור כללי של מה באמת הוכיח אנדרו ויילס, כשהשלים את הוכחת המשפט האחרון של פרמה.

2018 Jun 26

# Amitsur Symposium: Malka Schaps - "Symmetric Kashivara crystals of type A in low rank"

11:30am to 12:30pm

## Location:

Manchester House, Lecture Hall 2
The basis of elements of the highest weight representations of affine Lie algebra of type A can be labeled in three different ways, my multipartitions, by piecewise linear paths in the weight space, and by canonical basis elements. The entire infinite basis is recursively generated from the highest weight vector of operators f_i from the Chevalley basis of the affine Lie algebra, and organized into a crystal called a Kashiwara crystal. We describe cases where one can move between the different labelings in a non-recursive fashion, particularly when the crystal has some symmetry.
2018 Jun 27

# Amitsur Symposium: Tsachik Gelander - "Local rigidity of uniform lattices"

3:00pm to 4:00pm

## Location:

Manchester House, Lecture Hall 2
We establish topological local rigidity for uniform lattices in compactly generated groups, extending the result of Weil from the realm of Lie groups. We generalize the classical local rigidity theorem of Selberg, Calabi and Weil to irreducible uniform lattices in Isom(X) where X is a proper CAT(0) space with no Euclidian factors, not isometric to the hyperbolic plane. We deduce an analog of Wang’s finiteness theorem for certain non-positively curved metric spaces.
This is a joint work with Arie Levit.
2018 Jun 27

# Amitsur Symposium: Amiram Braun - "The polynomial question in modular invariant theory, old and new"

11:30am to 12:30pm

## Location:

Manchester House, Lecture Hall 2
Let G be a finite group, V a finite dimensional G- module over a field F, and S(V) the symmetric algebra of V. The above problem seeks to determine when is the ring of invariants S(V)^G , a polynomial ring. In the non-modular case (i.e. char(F) being prime to order(G)), this was settled in the Shephard-Todd-Chevalley theorem. The modular case (i.e. char(F) divides order (G) ), is still wide open. I shall discuss some older results due to Serre, Nakajima , Kemper-Malle and explain some new results, mostly in dimension 3.