2017 May 29

Combinatorics: Dmitry Faifman (U Toronto) "The integral geometry of indefinite signature"

11:00am to 1:00pm

Location:

Rothberg B220 (CS bldg)
Speaker: Dmitry Faifman (U Toronto)
Title: The integral geometry of indefinite signature.
2016 Nov 21

Combinatorics: David Ellis (Queen Mary) "Some applications of the $p$-biased measure to Erd\H{o}s-Ko-Rado type problems"

11:00am to 1:00pm

Location:

B220 Rothberg (CS)
Speaker: David Ellis, Queen Mary
Title: Some applications of the $p$-biased measure to Erd\H{o}s-Ko-Rado type problems
Abstract:
2018 Jan 08

Combinatorics Seminar: Boris Lishak "The space of triangulations of a compact 4-manifold"

11:00am to 12:30pm

Location:

Eilat Hall at IIAS
There are exponentially many triangulations of a fixed manifold extremely distant from each other in some natural metric. I will discuss similar results for contractible 2-complexes. In order to prove these for the manifold being the sphere (or a contractible complex) one needs to create topology out of nothing. This is done by studying group theory of the trivial group.
2017 Jan 09

Combinatorics: Ilan Karpas (HU) "Families with forbidden intersection patterns"

11:00am to 1:00pm

Location:

Rothberg B220 (CS bldg)
Speaker: Ilan Karpas, HU
Tilte: Families with forbidden intersection patterns
Abstract:
Let l, n be even natural numbers. A pattern p of length l is an element
p = (p1, . . . , pl) ∈ {−, +}^l. Given such a pattern and two sets A, B ⊂ [n], we say that the pair (A, B) forms pattern p if the following conditions are satisfied:
1. A \Delta B = {i_1, . . . , i_l}, where i_1 < i_2 < . . . < i_l,
2. For 1 ≤ j ≤ l, we have i_ j ∈ A \ B if p_ j = + and i_ j ∈ B \ A if p_ j = −.
2018 Jan 01

Combinatorics Seminar: Raphael Yuster

11:00am to 12:30pm

2017 May 07

Combinatorics: Jozsef Solymosi (UBC) Erdos lecture

11:00am to 1:00pm

2016 Nov 07

László Babai (U. Chicago) "Finite permutation groups and the Graph Isomorphism problem"

10:40am to 12:50pm

Location:

Israel Institute for Advanced Studies, Safra campus, Givat Ram
* This talk is joint with the 20th Midrasha Mathematicae: 60 faces to groups, celebrating Alex Lubotzky's 60th birthday.
The full program for AlexFest, Nov. 6--11, is detailed here:
http://www.as.huji.ac.il/ias/public/121/the20thMidrashaMa2016/program.pdf
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Speaker: László Babai (University of Chicago)
Title: Finite permutation groups and the Graph Isomorphism problem
Updated abstract:
The Graph Isomorphism (GI) problem is the algorithmic problem
2017 Dec 18

Combinatorics seminar: Orit Raz

11:00am to 12:30pm

Location:

Eilat Hal at IIAS

Title: Polynomials vanishing on Cartesian products
Abstract:
Let F(x,y,z) be a real trivariate polynomial of constant degree, and let A,B,C be three sets of real numbers, each of size n. How many roots can F have on A x B x C?
2017 Jan 02

Combinatorics: Ron Holzman (Technion) "Edge-covers in d-interval hypergraphs"

11:00am to 1:00pm

Location:

Rothberg B220 (CS)
Speaker: Ron Holzman, Technion
Title: Edge-covers in d-interval hypergraphs
2018 Jan 22

Combinatorics Seminar: Uli Wagner

11:00am to 12:30pm

Location:

Room 130, Feldman Building

Title: Shellability is NP-complete
2017 Mar 20

Combinatorics: Doron Puder (TAU) "Meanders and Non-Crossing Partitions"

11:00am to 1:00pm

Location:

Rothberg B220 (CS bldg)
Speaker: Doron Puder, TAU
Title: Meanders and Non-Crossing Partitions
Abstract: Imagine a long river and a closed (not self-intersecting) racetrack that crosses the river by bridges 2n times. This is called a meander. How many meanders are there with 2n bridges (up to homeomorphisms of the plane that stabilizes the river)? This challenging question, which is open for several decades now, has connections to several fields of mathematics.
2016 Jun 16

special talk: Bram Petri (Max Planck Institute, Bonn) "The length spectrum of a random surface"

11:00am to 12:00pm

Location:

Rothberg A410
Speaker: Bram Petri, Max Planck Institute, Bonn
Title: The length spectrum of a random surface
2017 Nov 13

Combinatorics seminar: Fedor Manin

11:00am to 12:30pm

2016 Dec 12

Combinatorics: Zur Luria (ETH)

11:00am to 1:00pm

Location:

B220 Rothberg (CS)
Speaker: Zur Luria (ETH)
Title: Hamiltonian spheres in random hypergraphs
Abstract:
Hamiltonian cycles are a fundamental object in graph theory, and combinatorics in general. A classical result states that in the random graph model G(n,p), there is a sharp threshold for the appearance of a Hamiltonian cycle. It is natural to wonder what happens in higher dimensions - that is, in random uniform hypergraphs?
2017 Nov 06

Combinatorics seminar: Eric Babson

11:00am to 12:30pm

130 at the IIAS