# Combinatorics: Daniel Jerison (TAU) "Random walks on sandpile groups"

## Location:

Title: Random walks on sandpile groups

Abstract:

2018
May
28

11:00am to 12:30pm

IIAS, Eilat hall, Feldman bldg, Givat Ram

Speaker: Daniel Jarison, TAU

Title: Random walks on sandpile groups

Abstract:

Title: Random walks on sandpile groups

Abstract:

2018
Jun
25

11:00am to 12:30pm

IIAS, room 130, Feldman bldg, Givat Ram

Speaker: Roman Glebov (HU)
Title: Perfect Matchings in Random Subgraphs of Regular Bipartite Graphs
Abstract:
Consider the random process in which the edges of a graph $G$ are
added one by one in a random order. A classical result states that if
$G$ is the complete graph $K_{2n}$ or the complete bipartite graph
$K_{n,n}$, then typically a perfect matching appears at the moment at
which the last isolated vertex disappears. We extend this result to
arbitrary $k$-regular bipartite graphs $G$ on $2n$ vertices for all
$k=\Omega(n)$.

2018
Jun
11

11:00am to 12:30pm

IIAS, Eilat hall, Feldman bldg, Givat Ram

Speaker: Chris Cox, CMU
Title -- Nearly orthogonal vectors
Abstract -- How can $d+k$ vectors in $\mathbb{R}^d$ be arranged so that they are as close to orthogonal as possible? In particular, define $\theta(d,k):=\min_X\max_{x

2018
Jun
12

2018
Apr
30

9:00am to 10:45am

Speaker: Stefan Glock (U. Birmingham)

Title: Designs via iterative absorption

2018
May
28

2:00pm to 3:00pm

Room 70A, Ross Building, Jerusalem, Israel

The celebrated Gan-Gross-Prasad conjectures aim to describe the branching behavior of representations of classical groups, i.e., the decomposition of irreducible representations when restricted to a lower rank subgroup.

2018
Apr
29

1:30pm to 2:30pm

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

Abstract:

We consider a setting where an auctioneer sells a single item to n potential agents with {\em interdependent values}. That is, each agent has her own private signal, and the valuation of each agent is a function of all n private signals. This captures settings such as valuations for oil fields, broadcast rights, art, etc. Read more about GAME THEORY AND MATHEMATICAL ECONOMICS RESEARCH SEMINAR:Michal Feldman, Tel Aviv University "Interdependent Values without Single-Crossing (Joint work with Alon Eden, Amos Fiat and Kira Goldner)"

2018
Apr
25

Justin Noel (University of Regensburg)

2:30pm to 3:30pm

Shprinzak 27

Abstract:

I will discuss a recent generalization of Kuhn's Blue-shift theorem about Tate cohomology. Combining this result with work of Arone, Dwyer, and Lesh we resolve a conjecture of Balmer and Sanders and classify the thick tensor ideals of compact genuine $A$-spectra, where $A$ is a finite abelian group. This is joint work with Tobias Barthel, Markus Hausmann, Niko Naumann, Thomas Nikolaus, and Nathaniel Stapleton.

2018
Jun
05

2018
Jun
19

2:15pm to 3:15pm

Ross 70

In recent years, topological dynamics have become an important tool in model theory. I will talk about some topological dynamical results from my PhD thesis about the so-called group-like equivalence relations. I plan to give a glimpse of the motivations in model theory (mostly related to the model-theoretic Galois groups and connected components of definable groups) and to show some ideas of the proofs.
I will briefly recall the required notions from topological dynamics. Some knowledge of model theory will help to understand the motivations, but otherwise, it will not be necessary.

2018
May
08

12:00pm to 1:00pm

Manchester 209

Consider a simple random walk on $\mathbb{Z}$ with a random coloring of $\mathbb{Z}$.
Look at the sequence of the first $N$ steps taken and colors of the visited locations.
From it, you can deduce the coloring of approximately $\sqrt{N}$ integers.
Suppose an adversary may change $\delta N$ entries in that sequence. What can be deduced now?
We show that for any $\theta<0.5,p>0$, there are $N_{0},\delta_{0}$
such that if $N>N_{0}$ and $\delta<\delta_{0}$ then with probability $>1-p$ we can reconstruct
the coloring of $>N^{\theta}$ integers.

2018
Apr
26

4:00pm to 5:30pm

Math Hall 2

Expander graphs have been a topic of great interest in the last 50 years for mathematicians and computer scientists. In recent years a high dimensional theory is emerging. We will describe some of its main directions and questions.

2018
May
16

12:00pm to 1:00pm

Ross Building

Abstract:
(joint with Noam Aigerman, Raz Sluzky and Yaron Lipman)

2018
May
15

2:15pm to 3:15pm

2018
May
29

12:00pm to 1:00pm

Manchester lounge

The Mass Transport Principle is a useful technique that was introduced to the study of automorphism-invariant percolations by Häggström in 1997. The technique is a sort of mass conservation principle, that allows us to relate random properties (such as the random degree of a vertex) to geometric properties of the graph.
I will introduce the principle and the class of unimodular graphs on which it holds, as well as a few of its applications.