Category Archives: Combinatorics

Beyond the g-conjecture – algebraic combinatorics of cellular spaces I

The g-conjecture for spheres is surely the one single conjecture I worked on more than on any other, and also here on the blog we had a sequence of posts about it by Eran Nevo (I,II,III,IV). Here is a great … Continue reading

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An Interview with Yisrael (Robert) Aumann

I was privileged to join Menachem Yaari and Sergiu Hart in interviewing Yisrael Aumann.  The interview is in Hebrew. It is an initiative of the Israel Academy of Sciences and the Humanities. For our non Hebrew speakers here is in … Continue reading

Posted in Academics, Combinatorics, Games, Geometry, Rationality | Tagged , , | 1 Comment

Igor Pak is Giving the 2018 Erdős Lectures in Discrete Mathematics and Theoretical Computer Science

Update: The lectures this week are cancelled.  They will be given at a later date. Next week Igor Pak will give the 2018 Erdős Lectures   Monday Jun 18 2018 Combinatorics — Erdos lecture: Igor Pak (UCLA) “Counting linear extensions” 11:00am to 12:30pm Location: … Continue reading

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Vera T. Sòs, Doctor Philisophiae Honoris Causa, Hebrew University of Jerusalem

Videotaped by Ehud Friedgut.

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Sailing into High Dimensions

On June 20 at 13:30 I talk here at HUJI about Sailing into high dimensions. (Thanks to Smadar Bergman for the poster.)

Posted in Combinatorics, Geometry, Updates | Tagged | 2 Comments

Conference in Singapore, Vietnam, Appeasement, Restorative Justice, Laws of History, and Neutrinos

Eliezer Rabinovici Some weeks ago I returned from a beautiful trip to Singapore and Vietnam. For both me and my wife this was the first trip to these very interesting countries. In Singapore I took part in a very unusual … Continue reading

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A Mysterious Duality Relation for 4-dimensional Polytopes.

Two dimensions Before we talk about 4 dimensions let us recall some basic facts about 2 dimensions: A planar polygon has the same number of vertices and edges. This fact, which just asserts that the Euler characteristic of is zero, … Continue reading

Posted in Combinatorics, Convex polytopes | Tagged | 5 Comments

Duncan Dauvergne and Bálint Virág Settled the Random Sorting Networks Conjectures

A short summary: The beautiful decade-old conjectures on random sorting networks by  Omer Angel, Alexander Holroyd, Dan Romik, and Bálint Virág, have now been settled by Duncan Dauvergne and Bálint Virág in two papers: Circular support in random sorting networks, by Dauvergne … Continue reading

Posted in Combinatorics, Probability, Updates | Tagged , , | 2 Comments

Zur Luria on the n-Queens Problem

(From Wikipedia ) The eight queens puzzle is the famous problem of placing eight chess queens on a chessboard so that no two queens threaten each other. The questions if this can be done and  in how many different ways, as well as the extension … Continue reading

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Testing *My* Intuition (34): Tiling High Dimension with an Arbitrary Low-Dimensional Tile.

Test your intuition 34 asked the following: A tile is a finite subset of . We can ask if can or cannot be partitioned into copies of . If   can be partitioned into copies of we say that tiles . Here … Continue reading

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