Combinatorics

  • 2019 Dec 09

    Combinatorics: Ilan Newman (Haifa)

    10:00am to 12:00pm

    Location: 

    C-400, CS building

    Speaker: Ilan Newman (Haifa)

    Title:  Some recent results on sublinear algorithms for graph related properties

    Abstract:
    I will describe property testing of (di)graph properties in bounded degree graph models, and talk about a characterization of the 1-sided error testable monotone graph properties and the 1-sided error testable hereditary graph properties in this model. I will introduce the notion of configuration-free properties and talk about some graph theoretic open problems.
  • 2019 Dec 02

    Combinatorics: Boaz Slomka (Open U.)

    10:00am to 12:00pm

    Location: 

    C-400, CS building

    Speaker: Boaz Slomka (Open U.)
    Title: On Hadwiger's covering problem



    Abstract:
    A long-standing open problem, known as Hadwiger’s covering problem, asks what is the smallest natural number N(n) such that every convex body in R^n can be covered by a union of the interiors of N(n) of its translates. 

    In this talk, I will discuss some history of this problem and its close relatives, and present more recent results, including a general upper bound for N(n).
  • 2019 Nov 11

    Combinatorics: Barak Weiss (TAU)

    10:00am to 12:00pm

    Location: 

    C-400, CS building

    Speaker: Barak Weiss (TAU)

    Title:  New bounds on the covering radius of a lattice.

    Abstract:

    We obtain new upper bounds on the minimal density of lattice coverings of R^n by dilates of a convex body K. We also obtain bounds on the probability (with respect to the natural Haar-Siegel measure on the space of lattices) that a randomly chosen lattice L satisfies L + K = R^n. As a step in the proof, we utilize and strengthen results on the discrete Kakeya problem. This is joint work with Or Ordentlich and Oded Regev. 

  • 2019 Jun 24

    Combinatorics: Doron Puder (TAU) "Aldous' spectral gap conjecture for normal sets"

    11:00am to 1:00pm

    Location: 

    CS bldg, room B-500, Safra campus
    Speaker: Doron Puder, TAU
    Title: Aldous' spectral gap conjecture for normal sets
    Abstract:
    Aldous' spectral gap conjecture, proved in 2009 by Caputo, Liggett and Richthammer, states the following a priori very surprising fact: the spectral gap of a random walk on a finite graph is equal to the spectral gap of the interchange process on the same graph.
  • 2019 Jun 17

    NO seminar: mini conference in memory of Prof. Yossi Zaks at U. Haifa

    11:00am to 1:00pm

    Location: 

    U. Haifa

    From Raphy Yuster: On Monday 17 June, 2019 we will hold a one day mini conference in memory of Professor Yossi Zaks
    (see attached poster or updated information in
    http://sciences.haifa.ac.il/math/wp/?page_id=1382 )
    Mini conference: Yossi Zaks Memorial Meeting – Monday, June 17, 2019
    list of speakers
    Noga Alon, Princeton University and Tel Aviv University
    Gil Kalai, Hebrew University
    Nati Linial, Hebrew University
    Rom Pinchasi, The Technion
    Organizers

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