Eventss

2019 May 22

Set Theory Seminar - Gabriel Fernandes (BIU) (part II)

2:00pm to 3:30pm

Location: 

Ross 63
Abstract: We combine a technique of Steel with one due to Jensen and Steel to
obtain a core model below singular cardinals kappa which are
sufficiently closed under the beth function, assuming that there is no
premouse of height kappa with unboundedly many Woodin cardinals.
The motivation for isolating such core model is computing a lower bound for the strength of
the theory: T = ''ZFC + there is a singular cardinal kappa such that the set of ordinals below kappa where GCH holds is stationary and co-stationary''.
2019 May 15

Set Theory Seminar - Gabriel Fernandes (BIU): Local core models with more Woodin cardinals

2:00pm to 3:30pm

Location: 

Ross 63
Abstract: We combine a technique of Steel with one due to Jensen and Steel to
obtain a core model below singular cardinals kappa which are
sufficiently closed under the beth function, assuming that there is no
premouse of height kappa with unboundedly many Woodin cardinals.
The motivation for isolating such core model is computing a lower bound for the strength of
the theory: T = ''ZFC + there is a singular cardinal kappa such that the set of ordinals below kappa where GCH holds is stationary and co-stationary''.
2019 Mar 12

T&G: John Pardon (Princeton), Structural results in wrapped Floer theory

1:00pm to 2:30pm

Location: 

Room 110, Manchester Building, Jerusalem, Israel
I will discuss results relating different partially wrapped Fukaya categories. These include a K\"unneth formula, a `stop removal' result relating partially wrapped Fukaya categories relative to different stops, and a gluing formula for wrapped Fukaya categories. The techniques also lead to generation results for Weinstein manifolds and for Lefschetz fibrations. The methods are mainly geometric, and the key underlying Floer theoretic fact is an exact triangle in the Fukaya category associated to Lagrangian surgery along a short Reeb chord at infinity.
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
2019 Apr 29

Combinatoric: Karthik C. Srikanta (Weizmann Institute) "On Closest Pair Problem and Contact Dimension of a Graph"

11:00am to 1:00pm

Location: 

CS B-500, Safra campus
Speaker: Karthik C. Srikanta (Weizmann Institute)
Title: On Closest Pair Problem and Contact Dimension of a Graph
Abstract: Given a set of points in a metric space, the Closest Pair problem asks to find a pair of distinct points in the set with the smallest distance. In this talk, we address the fine-grained complexity of this problem which has been of recent interest. At the heart of all our proofs is the construction of a family of dense bipartite graphs with special embedding properties and are inspired by the construction of locally dense codes.
2019 Apr 08

Combinatorics: Kim Minki (Technion) "The fractional Helly properties for families of non-empty sets"

11:00am to 1:00pm

Location: 

CS B-500, Safra campus
Speaker: Kim Minki, Technion
Title: The fractional Helly properties for families of non-empty sets
Abstract:
Let $F$ be a (possibly infinite) family of non-empty sets.
The Helly number of $F$ is defined as the greatest integer $m = h(F)$ for which there exists a finite subfamily $F'$ of cardinality $m$ such that every proper subfamily of $F'$ is intersecing and $F'$ itself is not intersecting.
For example, Helly's theorem asserts that the family of all convex sets in $d$-dimensional Euclidean space has Helly number $d+1$.
2019 Apr 15

Combinatorics: problem session

11:00am to 1:00pm

Location: 

CS B-500, Safra campus
Speaker: Eyal Karni, BIU Title: Combinatorial high dimensional expanders Abstract: An eps-expander is a graph G=(V,E) in which every set of vertices X where |X|<=|V|/2 satisfies |E(X,X^c)|>=eps*|X| . There are many edges that "go out" from any relevant set.
2019 Apr 01

Combinatorics: Raphy Yuster (U. Haifa) "On some Ramsey type problems in tournaments"

11:00am to 1:00pm

Location: 

CS B-500, Safra campus
Speaker: Raphy Yuster, U. Haifa
Title: On some Ramsey type problems in tournaments
Abstract:
I will talk about several Ramsey type problems in tournaments guaranteeing the existence of subgraphs with certain chromatic properties.
Here are two such problems which attracted some attention recently:
1. Let g(n) be the smallest integer such that every tournament with more than g(n) vertices has an *acyclic subgraph* with chromatic number larger than n.
2019 Mar 07

Emmanuel Roy (Paris 13) Non-singular Poisson suspensions

2:45pm to 3:45pm

Location: 

Ross 70
Poisson suspensions are random sets of points endowed with a transformation that displaces each point according to a single transformation of the sigma-finite space where the points lie. In this ongoing work, instead of dealing with measure-preserving transformations (which is the classical case), we are going to present our attempt to explore the non-singular case. The difficulties are counterbalanced by new tools that are trivial in the measure-preserving case but highly informative in the non-singular one.

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