2019 Dec 18

# Analysis Seminar: Moshe Goldberg (Technion) "Extending the Spectral Radius to Finite-Dimensional Power-Associative Algebras"

12:00pm to 1:00pm

## Location:

Ross 70

Title: Extending the Spectral Radius to Finite-Dimensional Power-Associative Algebras
Abstract: The purpose of this talk is to introduce a new concept, the \textit{radius} of elements in arbitrary finite-dimensional power-associative algebras over the field of real or complex numbers. It is an extension of the well known notion of the spectral radius.
As examples, we shall discuss this new radius in the setting of matrix algebras, where it indeed reduces to the spectral radius, and then in the Cayley-Dickson algebras, where it is something quite different.
2019 Dec 12

# Colloquium: Menachem Lazar (Bar Ilan) - Spatial point sets, level set geometry, and Voronoi topology structure analysis

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem
Physical systems are regularly studied as spatial point sets, and so understanding the structure in such sets is a very natural problem. However, aside from several special cases, describing the manner in which a set of points can be arranged in space has been historically challenging. In the first part of this talk, I will show how consideration of the configuration space of local arrangements of neighbors, and a few simple results in metric geometry, can shed light on essential challenges of this problem, and in the classification of data more generally.
2019 Oct 31

# Colloquium: Leonid Polterovich (TAU) - Quantum footprints of symplectic rigidity

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem
Title: Quantum footprints of symplectic rigidity
Abstract: I'll discuss an interaction between symplectic topology, a rapidly developing mathematical area originated as a geometric language for problems of classical mechanics, and quantum mechanics. On one hand, ideas from quantum mechanics give rise to new structures on the symplectic side, and quantum mechanical insights lead to useful symplectic predictions. On the other hand, some phenomena discovered within symplectic topology admit a translation into the language of quantum mechanics.
2020 Mar 08

# **Cancelled** Ohalo Seminar on Random walks, equidistribution, and rigidity

Sun, 08/03/2020 (All day) to Fri, 13/03/2020 (All day)

## Location:

Ohalo, Israel

The workshop will consist of four main mini-courses and several additional lectures, taking place on the shore of the Sea of Galilee, at Ohalo Manor Hotel.

2019 Nov 13

# Analysis Seminar: Misha Sodin (TAU) "The Wiener spectrum and Taylor series with pseudo-random coefficients"

12:00pm to 1:00pm

## Location:

Ross 70
Title: The Wiener spectrum and Taylor series with pseudo-random coefficients.
Abstract:
2019 Sep 21

# Yuka received תולעת הפרק vaccination

10:15am to 11:15am

2019 Nov 07

# Colloquium: Boaz Klartag (Weizmann) - Needle decomposition and Ricci curvature

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem
Title: Needle decomposition and Ricci curvature
Abstract: Needle decomposition is a technique in convex geometry,
which enables one to prove isoperimetric and spectral gap
inequalities, by reducing an n-dimensional problem to a 1-dimensional
one. This technique was promoted by Payne-Weinberger, Gromov-Milman
and Kannan-Lovasz-Simonovits. In this lecture we will explain what
needles are, what they are good for, and why the technique works under
lower bounds on the Ricci curvature.
2019 Dec 19

# Zabrodsky Lectures: Paul Seidel (MIT)

Thu, 19/12/2019 (All day) to Tue, 24/12/2019 (All day)

2019 Dec 24

# Zabrodsky Lecture 3: The symplectic topologist as a homotopy theorist

## Lecturer:

Paul Seidel (MIT)
1:00pm to 2:00pm

## Location:

Ross Building, Room 70

Modern symplectic topology deals with objects of symplectic geometry indirectly, by associating to them auxiliary moduli spaces. This complicates its relation with homotopy theory. I will explain the overall framework that describes this relation (going back to Cohen, Jones and Segal), and some of the directions that are under investigation.

2019 Dec 23

# Zabrodsky Lecture 2: The symplectic topologist as a number theorist

## Lecturer:

Paul Seidel (MIT)
1:00pm to 2:00pm

## Location:

Ross Building, Room 70

Most of the complications of classical topology have to do with torsion phenomena, say by looking at homology with modulo p coefficients. In principle, the same is true for symplectic topology, but the implications are only beginning to be explored. A particular impetus is provided by mirror symmetry, which links symplectic topology with arithmetic geometry.

2019 Nov 20

# Analysis Seminar: Genadi Levin "The Cauchy transform that vanishes outside a compact"

12:00pm to 1:00pm

## Location:

Ross 70

Title: The Cauchy transform that vanishes outside a compact.
Abstract: The Cauchy transform of a complex finite compactly supported measure on the plane is its convolution with the Cauchy kernel.
The classical F. and M. Riesz theorem asserts that if the Cauchy transform of a measure $\mu$ on the unit circle
vanishes off the closed unit disk then $\mu$ is absolutely continuous w.r.t. the arc measure on the unit circle.
Motivated by an application in holomorphic dynamics we present a certain generalization of this Riesz theorem
2019 Dec 04

# Analysis Seminar: Orr Shalit (Technion) " On the matrix range of random matrices"

12:00pm to 1:00pm

## Location:

Ross 70

Title: On the matrix range of random matrices
2019 Dec 11

# Analysis Seminar: Matania Ben-Artzi (HUJI) "Spline functions, the biharmonic operator and approximate eigenvalues"

12:00pm to 1:00pm

## Location:

Ross 70
Title: Spline functions, the biharmonic operator and approximate
eigenvalues.
Abstract: The biharmonic operator plays a central role in a wide array of physical models, such as elasticity theory and the streamfunction formulation of the Navier-Stokes equations.In this talk a full discrete elliptic calculus is presented. The primary object of this calculus is a high-order compact discrete biharmonic operator (DBO).
2019 Nov 27

# Analysis Serminar: Ami Viselter, Haifa "Locally compact quantum groups: introduction, examples, and some recent results"

12:00pm to 1:00pm

## Location:

Ross 70
Title: Locally compact quantum groups: introduction, examples, and some recent results
2019 Dec 26

# Colloquium: Boaz Haberman (UCF)

2:30pm to 3:30pm

## Location:

Manchester Building (Hall 2), Hebrew University Jerusalem

A variety of algebra is a concept like "monoid", "group" or "ring" (but not "field"), which can be axiomatized by finitary operations (e.g. multiplication, inversion) and universally quantified axioms (e.g. associativity).