2017 Nov 15

Jerusalem Analysis Seminar: "Operators and random walks", Gady Kozma (Weizmann Institute)

12:00pm to 1:00pm

Location:

Ross 70 (NOTE LOCATION!)
Abstract: We will discuss the question: for a random walk in a random environment, when should one expect a central limit theorem, i.e. that after appropriate scaling, the random walk converges to Brownian motion? The answer will turn out to involve the spectral theory of unbounded operators. All notions will be defined in the talk. Joint work with Balint Toth.
2017 Mar 09

Analysis and PDEs: Iosif Polterovich (Montreal) - Nodal Geometry of Steklov Eigenfunctions

12:00pm to 1:00pm

Location:

Ross 70
I will present an overview of some recent progress on the study of the nodal sets of Steklov eigenfunctions. In particular, I will discuss sharp estimates on the nodal length of Steklov eigenfunctions on real-analytic Riemannian surfaces with boundary obtained in my joint work with D. Sher and J. Toth.
2017 May 18

Mark Rudelson: Delocalization of the eigenvectors of random matrices.

1:00pm to 2:00pm

Location:

Ross 70
Abstract: Consider a random matrix with i.i.d. normal entries. Since its distribution is invariant under rotations, any normalized eigenvector is uniformly distributed over the unit sphere. For a general distribution of the entries, this is no longer true. Yet, if the size of the matrix is large, the eigenvectors are distributed approximately uniformly. This property, called delocalization, can be quantified in various senses. In these lectures, we will discuss recent results on delocalization for general random matrices.
2016 Mar 31

PDE & Analysis: Mark Ruselson (UMichigan) - No-gaps delocalization for general random matrices.

1:00pm to 2:30pm

Location:

Ross 70
Title: No-gaps delocalization for general random matrices. Abstract:
2017 Dec 20

Jerusalem Analysis Seminar: "Translation invariant probability measures on the space of entire functions." Adi Glucksam

12:00pm to 1:00pm

Location:

Ross 70
20 years ago Weiss constructed a collection of non-trivial translation invariant probability measures on the space of entire functions using tools from dynamical systems. In this talk, we will present another elementary construction of such a measure, and give upper and lower bounds for the possible growth of entire functions in the support of such measures.
2016 Dec 22

Analysis and PDE's Seminar -- Percy Deift (Courant)

1:00pm to 2:00pm

Location:

Ross 70
On the Asymptotic behavior of a log gas in the bulk scaling limit in the presence of a varying external potential. T.Bothner, P.Deift, A.Its and I.Krasovsky Abstract: We study the partition function Z of a Coulomb gas of particles with an external potential 2v applied to the particles in an interval of length L. When v is infinite, Z describes the gap probability for GUE eigenvalues in the bulk scaling limit, and has been well-studied for many years. Here we study the the behavior of Z in the full (v,L) plane.
2017 May 17

Mark Rudelson: Delocalization of the eigenvectors of random matrices.

2:00pm to 3:00pm

Location:

רוס 63
Abstract: Consider a random matrix with i.i.d. normal entries. Since its distribution is invariant under rotations, any normalized eigenvector is uniformly distributed over the unit sphere. For a general distribution of the entries, this is no longer true. Yet, if the size of the matrix is large, the eigenvectors are distributed approximately uniformly. This property, called delocalization, can be quantified in various senses. In these lectures, we will discuss recent results on delocalization for general random matrices.
2017 Dec 13

Jerusalem Analysis Seminar: "Exponential concentration of zeroes of Gaussian stationary functions" Naomi Feldheim (Weizmann Institute)

12:00pm to 1:00pm

Location:

Ross 70
A Gaussian stationary function (GSF) is a random f: R --> R whose distribution is shift-invariant and all its finite marginals have centered multi-normal distribution. It is a simple and popular model for noise, for which the mean number of zeroes was computed already in the 1940's by Kac and Rice. However, it is far more complicated to estimate the probability of a significant deficiency or abundance in the number of zeroes in a long interval (compared to the expectation). We do so for a specific family of GSFs with additional smoothness and absolutely
2016 Nov 17

Analysis and PDEs- A. Logunov "The zero set of a nonconstant harmonic function in R^3 has infinite area"

1:00pm to 2:00pm

Location:

Ross 70
Abstract. We will give a sketch of the proof of the fact formulated in the title.
2017 Mar 23

Xiaolin Zeng (TAU)

1:00pm to 2:00pm

Location:

Ross 70
Title: a random Schroedinger operator stemming from reinforced process Abstract: We will explain the relationship between a toy model to Anderson localization, called the H^{2|2} model (according to Zirnbauer) and edge reinforced random walk. The latter is a random walk in which, at each step, the walker prefers traversing previously visited edges, with a bias proportional to the number of times the edge was traversed. Recent study on this random walk showed that it is equivalent to Zirnbauer's model and we will show some consequences once this equivalence is established.
2017 Jun 13

Topology and Geometry Seminar: Alexander Caviedes Castro (Tel-Aviv University), "Symplectic capacities and Cayley graphs"

1:00pm to 1:50pm

Location:

Ross 70A
Abstract: The Gromov non-squeezing theorem in symplectic geometry states that is not possible to embed symplectically a ball into a cylinder of smaller radius, although this can be done with a volume preserving embedding. Hence, the biggest radius of a ball that can be symplectically embedded into a symplectic manifold can be used as a way to measure the "symplectic size'' of the manifold. We call the square of this radius times the number \pi the Gromov width of the symplectic manifold. The Gromov width as a symplectic invariant is extended through the notion of "Symplectic Capacity".
2017 Aug 09

Topology and Geometry Seminar: "Bordered methods in knot Floer homology" Peter Ozsvath, Princeton University

12:00pm to 1:00pm

Location:

Ross 70A
Abstract: Knot Floer homology is an invariant for knots in the three-sphere defined using methods from symplectic geometry. I will describe a new algebraic formulation of this invariant which leads to a reasonably efficient computation of these invariants. This is joint work with Zoltan Szabo.
2017 May 09

Topology & Geometry Seminar: Serap Gurer (Galatasaray University), "(Co)homology theories on diffeological spaces".

11:00am to 12:00pm

Location:

Ross A70.
Abstract: In this talk, I will introduce diffeological spaces and some (co)homology theories on these spaces. I will also talk on Thom-Mather spaces and their (co)homology in the diffeological context.
2018 Jan 15

HD-Combinatorics: Alexander Gamburd, "Arithmetic and Dynamics on Markoff-Hurwitz Varieties"

2:00pm to 4:00pm

Location:

IIAS, Feldman Building, Givat Ram
Markoff triples are integer solutions to Markoff equation $x^2+y^2+z^2=3xyz$ which arose in Markoff's spectacular and fundamental work (1879) on diophantine approximation and has been henceforth ubiquitous in a tremendous variety of different fields in mathematics and beyond.
2017 Nov 06

4:00pm to 6:00pm

Room 130