2019 Jun 03

# NT & AG Seminar: Shuddhodan K V (HUJI) "Self maps of varieties over finite fields"

2:30pm to 3:30pm

## Location:

Ross building 70
Title: Title: Self maps of varieties over finite fields
Abstract: Esnault and Srinivas proved that as in Betti cohomology over the complex numbers, the value of the entropy of an automorphism of a smooth proper surface over a finite field $\F_q$ is taken in the subspace spanned by algebraic cycles inside $\ell$-adic cohomology. In this talk we will discuss some analogous questions in higher dimensions motivated by their results and techniques.
2019 May 30

# Basic Notions: Eugene Trubowitz (ETH) "Mathematical Methods of Many Body Quantum Field Theory"

4:00pm to 5:15pm

## Location:

Ross 70
Let (V,<, >) be a finite dimensional inner product space and K a self adjoint element of End(V ). It is an axiom of physics that the expected value of A in End(V ) in equilibrium at temperature T with respect to K is
the ration Tr(A exp (-K/T))/Tr(exp (-K/T)).
2019 Jun 06

# Basic Notions: Eugene Trubowitz (ETH) "Mathematical Methods of Many Body Quantum Field Theory"

4:00pm to 5:15pm

## Location:

Ross 70
Let (V,<, >) be a finite dimensional inner product space and K a self adjoint element of End(V ). It is an axiom of physics that the expected value of A in End(V ) in equilibrium at temperature T with respect to K is
the ration Tr(A exp (-K/T))/Tr(exp (-K/T)).
2019 May 21

# Special groups theory seminar: Abdalrazzaq R A Zalloum (Suny Buffalo) "Regular languages for hyperbolic-like geodesics".

4:00pm to 5:00pm

## Location:

Ross 63
Combinatorial group theory began with Dehn's study of surface
groups, where he used arguments from hyperbolic geometry to solve the
word/conjugacy problems. In 1984, Cannon generalized those ideas to all
"hyperbolic groups", where he was able to give a solution to the
word/conjugacy problem, and to show that their growth function satisfies
a finite linear recursion. The key observation that led to his
discoveries is that the global geometry of a hyperbolic group is determined locally:
2019 May 21

# Special groups theory seminar: Abdalrazzaq R A Zalloum (Suny Buffalo) "Regular languages for hyperbolic-like geodesics".

4:00pm to 5:00pm

## Location:

Ross 63
Combinatorial group theory began with Dehn's study of surface groups, where he used arguments from hyperbolic geometry to solve the word/conjugacy problems. In 1984, Cannon generalized those ideas to all "hyperbolic groups", where he was able to give a solution to the word/conjugacy problem, and to show that their growth function satisfies a finite linear recursion. The key observation that led to his discoveries is that the global geometry of a hyperbolic group is determined locally: first, one discovers the local picture of G, then the recursive structure
2019 May 28

# Dynamics Lunch: Uri Gabor ״Percolation on finite graphs and isoperimetric inequalities" of Alon, Benjamini and Stacey (2004)״

12:00pm to 1:00pm

Following the paper “ Preperiodic points and unlikely intersection” by Baker and DeMarco.
2019 Jun 25

# Dynamics Lunch: Michael Chapman ״Markoff triples״

12:00pm to 1:00pm

Partially based on the paper "The Markoff Group of Transformations in Prime and Composite Moduli" by Meiri and Puder.
2019 Jun 03

# NT & AG Lunch: Michael Temkin "The explicit local class field theory"

1:00pm to 2:00pm

## Location:

Faculty lounge, Math building

I'll tell a couple of anecdotes related to imaginary quadratic fields
(e.g. primes in the sequence n^2+n+41), and then open a new story --
local CFT and the explicit construction of K^ab due to Lubin-Tate.
2019 Jun 04

# Dynamics Seminar: Arie Levit - Surface groups are flexibly stable

12:00pm to 1:00pm

This will be a research talk. The abstract is below:
A group G is stable in permutations if every almost-action of G on a finite set is close to some actual action. Part of the interest in this notion comes from the observation that a non-residually finite stable group cannot be sofic.
I will show that surface groups are stable in a flexible sense, that is if one is allowed to "add a few extra points" to the action. This is the first non-trivial stability result for a non-amenable group.
2019 May 21

# T&G: David Nadler (Berkeley), What kind of an invariant are microlocal sheaves?

11:00am to 12:30pm

## Location:

Room 07, Levi Building, Jerusalem, Israel
I will give an introduction to sheaves and microlocal sheaves, as pioneered by Kashiwara-Schapira. The goal will be to explain recent work with Shende establishing that microlocal sheaves on a Weinstein manifold are a symplectic invariant.
2019 Jun 11

# Dynamics seminar: Genadi Levin " Transversality and transfer operators with applications to monotonicity of interval maps"

2:00pm to 3:00pm

Abstract. We consider families of holomorphic maps defined on subsets of the complex plane,
2019 May 13

2:00pm to 3:00pm

Ross 63
_
2019 May 14

# Dynamics Lunch: Hongming Nie "Preperiodic points of unicritial polynomials”.

12:00pm to 1:00pm

Following the paper “ Preperiodic points and unlikely intersection” by Baker and DeMarco.
2019 May 13

# NT & AG Lunch: Michael Temkin "Elliptic curves with complex multiplication, II"

1:00pm to 2:00pm

## Location:

Faculty lounge, Math building
2019 May 13

# NT & AG Seminar: "A dream desingularization algorithm", Michael Temkin (HU)

2:30pm to 4:00pm

## Location:

Ross 70
Abstract: Any birational geometer would agree that the best algorithm
for resolution of singularities should run by defining a simple invariant of
the singularity and iteratively blowing up its maximality locus.
The only problem is that already the famous example of Whitney umbrella
shows that this is impossible, and all methods following Hironaka had
to use some history and resulted in more complicated algorithms.
Nevertheless, in a recent work with Abramovich and Wlodarczyk we did