2019 Apr 10

# Special Analysis Seminar: Dirk Hundertmark (Karlsruhe) "Cwikel's bound reloaded"

2:30pm to 3:30pm

## Location:

Sprinzak 24
Title: Cwikel's bound reloaded Abstract: There are a couple of proofs by now for the famous Cwikel--Lieb--Rozenblum (CLR) bound, which is a semiclassical bound on the number of bound states for a Schr\"odinger operator, proven in the 1970s.
2019 Jun 19

# Analysis Seminar: Daniel Ofner (HUJI) "Mesoscopic universality for orthogonal polynomial ensembles on the unit circle"

12:00pm to 1:00pm

## Location:

Ross 70
Title: Mesoscopic universality for orthogonal polynomial ensembles on the unit circle
2019 May 22

# Analysis seminar: Yoel Grinshpon "Fluctuations of linear statistics for Schroedinger operators with a random decaying potential"

12:00pm to 1:00pm

## Location:

Ross 70
Title: Fluctuations of linear statistics for Schroedinger operators with a random decaying potential Abstract: Linear statistics provide a tool for the analysis of fluctuations of random measures and have been extensively studied for various models in random matrix theory. In this talk we discuss the application of the same philosophy to the analysis of the finite volume eigenvalue counting measure of one dimensional Schroedinger operators and demonstrate it with some interesting results in the case of a random decaying potential. This is joint work with Jonathan Breuer and Moshe White.
2019 Mar 13

# Analysis Seminar: Yehuda Pinchover (Technion) "How large can Hardy-weight be?"

12:00pm to 1:00pm

## Location:

Ross 70
Title: How large can Hardy-weight be? Abstract: In the first part of the talk we will discuss the existence of optimal Hardy-type inequalities with 'as large as possible' Hardy-weight for a general second-order elliptic operator defined on a noncompact Riemannian manifold, while the second part of the talk will be devoted to a sharp answer to the question: "How large can Hardy-weight be?"
2019 Feb 07

# Special group actions seminar. On Tame Subgroups of Finitely Presented Groups: Prof. Rita Gitik, University of Michigan, Ann Arbor.

10:00am to 11:00am

## Location:

Ross 70
We describe several examples of tame subgroups of finitely presented groups and prove that the fundamental groups of certain finite graphs of groups are locally tame.
2019 Jan 23

# T&G: Sylvain Cappell (NYU), Atiyah-Bott classes and extending representations of fundamental groups of 3-manifolds from part of the boundary

1:00pm to 2:00pm

## Location:

Room 70, Ross Building, Jerusalem, Israel
We consider the problem of extending a representation of the fundamental group of 3-manifolds from part of the boundary surfaces. Applications to links will be discussed. Combining this with some cohomology classes of Atiyah and Bott leads to new multivariable polynomial invariants of 3-manifolds with boundary. This is joint work with Edward Miller. No background in 3-dimensional topology will be assumed in this survey and research talk.
2019 Mar 19

# Dynamics Seminar: Elon Lindenstrauss (HUJI) - Double variational principle for mean dimension

2:15pm to 3:15pm

Mean dimension is a topological invariant of dynamical systems introduced by Gromov that measures the number of parameters per iteration needed to describe a trajectory in the system. We characterize this invariant (at least for dynamical systems with the marker property, such as infinite minimal systems) using a min-max principle, where choices of both a metric on the topological space and an invariant probability measure on the system are varied. The work I will report on is joint work with M. Tsukamoto.
2019 Jan 15

# T&G: Michael Khanevsky (Technion), Geometry of sets of Hamiltonian isotopic curves in a symplectic surface

2:00pm to 3:30pm

## Location:

Room 209, Manchester Building, Jerusalem, Israel
Given two Hamiltonian isotopic curves in a surface, one would like to tell whether they are "close" or "far apart". A natural way to do that is to consider Hofer's metric which computes mechanical energy needed to deform one curve into the other. However due to lack of tools the large-scale Hofer geometry is only partially understood. On some surfaces (e.g. S^2) literally nothing is known.
2019 May 15

# Analysis Seminar: Matthias Keller (Potsdam) "Path integral representations for magnetic Schroedinger operators on graphs"

12:00pm to 1:00pm

## Location:

Ross 70
Title: Path integral representations for magnetic Schroedinger operators on graphs Abstract: We consider the semigroup and the unitary group of magnetic Schrödinger operators on graphs. Using the ideas of the Feynman Kac formula, we develop a representation of the semigroup and the unitary group in terms of the stochastic process associated with the free Laplacian. As a consequence we derive Kato-Simon estimates for the unitary group. This is joint work with Batu Güneysu (Bonn).
2019 Apr 02

# Dynamics Seminar : Yonatan Gutman (IMPAN). On Almost Lossless Compression

2:15pm to 3:15pm

## Location:

Ross 70
Abstract: We answer the following questions: 1. Consider a Borel set $X \subset \R^N$ equipped with a probability measure $\mu$. For fixed \$k
2019 Jan 09

# Set Theory Seminar - Ur Yaar (Set Theory Seminar - Ur Yaar Set Theory Seminar - Ur Yaar Set Theory Seminar - Ur Yaar Set Theory Seminar - Ur Yaar Set Theory Seminar - Ur Yaar )Set Theory Seminar - Ur Yaar Set Theory Seminar - Ur Yaar

2:00pm to 3:30pm

## Location:

Ross 73
Title: The Modal Logic of Forcing (Part III) Abstract: Modal logic is used to study various modalities, i.e. various ways in which statements can be true, the most notable of which are the modalities of necessity and possibility. In set-theory, a natural interpretation is to consider a statement as necessary if it holds in any forcing extension of the world, and possible if it holds in some forcing extension. One can now ask what are the modal principles which captures this interpretation, or in other words - what is the "Modal Logic of Forcing"?
2019 Apr 30

# Dynamics Lunch: Nishant Chandgotia "Generic properties of Lebesgue measure preserving transformations of the 2-torus."

12:00pm to 1:00pm

Abstract: In this talk we will discuss some recent work by Guihéneuf and Lefeuvre who prove that shadowing is generic for Lebesgue measure preserving transformations of the 2-torus. We will spend most of our time motivating the problem, discussing the history of such questions- specifically touching upon earlier work of Oxtoby, Ulam, Alpern and Prasad and some general techniques used in the area. Time permitting, we will discuss the recent proof given by Guihéneuf and Lefeuvre.
2019 Mar 27

# Eshnav: Prof. Benjamin Weiss : What is a Sofic group?

6:00pm to 7:15pm

## Location:

Manchester House, Lecture Hall 2
2019 Jan 08

# T&G: David Treumann (Boston College), The Fargues-Fontaine curve for symplectic geometers -- NOTE special time and location

4:00pm to 5:30pm

## Location:

Room 70, Ross Building, Jerusalem, Israel
I will review homological mirror symmetry for the torus, which describes Lagrangian Floer theory on T^2 in terms of vector bundles on the Tate elliptic curve --- a version of Lekili and Perutz's works "over Z", where t is the Novikov parameter. Then I will describe a modified form of this story, joint with Lekili, where the Floer theory is altered by a locally constant sheaf of rings on T^2 (an "F-field").
2019 Jan 01

# Dynamics Lunch: Zemer Kosloff: On the action of the permutation group on the cantor set (after Aldous-Pitman and Stratila-Voiculescu)

12:00pm to 1:00pm