# Eventss

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

## Lecturer:

## Location:

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.

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

## Location:

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.

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

## Location:

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?

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

## Location:

Decoupling has applications to problems in PDE and also to analytic number theory. One application involves exponential sums, sums of the form

$$\sum_j e^{2 pi i \omega_j x}.$$

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

## Location:

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

## Lecturer:

## Location:

**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.

# Amitsur Symposium: Lev Glebsky - "Approximations of groups by finite and linear groups"

## Location:

and by unitary groups, respectively. I recall their definitions and discuss why those classes of groups are interesting. Then I consider approximations by other classes of groups and review some results, including rather recent ones by N. Nikolov, J. Schneider, A.Thom, https://arxiv.org/abs/1703.06092 .

If time permits I'll speak about stability and its relations with approximability.

# Amitsur Symposium: Arye Juhasz - "On the center of Artin groups"

## Location:

It is conjectured that all other irreducible Artin groups have trivial center. I prove this conjecture under a stronger assumption that not being spherical namely, if there is a standard generator which is not contained in any 3-generated spherical standard parabolic subgroup. The main tool is relative presentations of Artin groups.

# Amitsur Symposium: Yael Algom-Kfir - "The metric completion of an asymmetric metric space"

## Location:

eq d(y,x). The latter case is also incomplete: There exist Cauchy sequences that do not have a limit. We develop the theory of the completion of an asymmetric space and give lots of examples. Time permitting we will describe the case of Outer Space.

# Amitsur Symposium: Alex Lubotzky - "First order rigidity of high-rank arithmetic groups"

## Location:

It includes SL(n,Z), for n>2 , SL(n, Z[1/p] ) for n>1, their finite index subgroups and many more.

A number of remarkable results about them have been proven including; Mostow rigidity, Margulis Super rigidity and the Quasi-isometric rigidity.