2018
Apr
09

# Eventss

2018
Jun
05

# Tom Meyerovitch (BGU): On expansivness, topological dimension and mean dimesnion

2:15pm to 3:15pm

## Location:

Ross 70

Expansivness is a fundamental property of dynamical systems.

It is sometimes viewed as an indication to chaos.

However, expansiveness also sets limitations on the complexity of a system.

Ma\~{n}'{e} proved in the 1970’s that a compact metric space that

admits an expansive homeomorphism is finite dimensional.

In this talk we will discuss a recent extension of Ma\~{n}'{e}’s

theorem for actions generated by multiple homeomorphisms,

based on joint work with Masaki Tsukamoto. This extension relies on a

It is sometimes viewed as an indication to chaos.

However, expansiveness also sets limitations on the complexity of a system.

Ma\~{n}'{e} proved in the 1970’s that a compact metric space that

admits an expansive homeomorphism is finite dimensional.

In this talk we will discuss a recent extension of Ma\~{n}'{e}’s

theorem for actions generated by multiple homeomorphisms,

based on joint work with Masaki Tsukamoto. This extension relies on a

2018
Apr
10

2018
Apr
24

# No seminar

2:00pm to 3:00pm

2018
May
01

# No Dynamics Seminar (Zabrodsky talk)

2:00pm to 3:00pm

2018
Apr
16

2018
Apr
09

2018
May
31

# Tamar Ziegler (Hebrew University) - "Concatenating cubic structure and polynomial patterns in primes"

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem

A major difficulty in finding polynomial patterns in primes is the need to understand their distribution properties at short scales. We describe how for some polynomial configurations one can overcome this problem by concatenating short scale behavior in "many directions" to long scale behavior for which tools from additive combinatorics are available.

2018
Jun
07

# Colloquium: Gabriel Conant (Notre Dame) - "Pseudofinite groups, VC-dimension, and arithmetic regularity"

2:15pm to 3:15pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem

Given a set X, the notion of VC-dimension provides a way to measure randomness in collections of subsets of X. Specifically, the VC-dimension of a collection S of subsets of X is the largest integer d (if it exists) such that some d-element subset Y of X is ""shattered"" by S, meaning that every subset of Y can be obtained as the intersection of Y with some element of S. In this talk, we will focus on the case that X is a group G, and S is the collection of left translates of some fixed subset A of G.

2018
May
10

# Colloquium: Zemer Kosloff (Hebrew University) - "Poisson point processes, suspensions and local diffeomprhisms of the real line"

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem

The study of the representations theoretic properties of the group of diffeormorphisms of locally compact non compact Riemmanian manifolds which equal to the identity outside a compact set is is linked to a natural quasi invariant action of the group which moves all points of a Poisson point process according to the diffeomorphism (Gelfand-Graev-Vershik and Goldin et al.).

Neretin noticed that the local diffeomorphism group is a subgroup of a larger group which he called GMS and that GMS also acts in a similar manner on the Poisson point process.

Neretin noticed that the local diffeomorphism group is a subgroup of a larger group which he called GMS and that GMS also acts in a similar manner on the Poisson point process.

2018
Jun
19

# Dynamics Lunch: Amichai Lampert (Huji) "Equidistribution of Zeros of Polynomials"

12:00pm to 1:00pm

## Location:

Manchester lounge

A classical theorem of Erdos and Turan states that if a monic polynomial has small values on the unit circle (relative to its constant coefficient), then its zeros cluster near the unit circle and are close to being equidistributed in angle. In February 2018, K. Soundararajan gave a short and elementary proof of their result using Fourier analysis. I'll present this new proof.

2018
May
01

# Dynamics Lunch: Ofir David (Huji) "On Minkowski's conjecture"

12:00pm to 1:00pm

## Location:

Manchester lounge

One of the first algorithm any mathematician learns about is the Euclidean division algorithm for the rational integer ring Z. When asking whether other integer rings have similar such division algorithms, we are then led naturally to a geometric interpretation of this algorithm which concerns lattices and their (multiplicative) covering radius.

2018
Apr
24

2018
Apr
10

2018
Mar
25

# Game theory: Jeffrey Mensch, HUJI "Cardinal Representations of Information"

2:00pm to 3:00pm

## Location:

Elath Hall, 2nd floor, Feldman Building, Edmond Safra Campus