Category Archives: Combinatorics

NogaFest, NogaFormulas, and Amazing Cash Prizes

Ladies and gentlemen,  a conference celebrating Noga Alon’s 60th birthday is coming on January. It will take place at Tel Aviv University on January 17-21. Here is the event webpage. Don’t miss the event !  Cash Prizes! The poster includes 15 … Continue reading

Posted in Combinatorics, Conferences, Updates | Tagged , | 30 Comments

Choongbum Lee proved the Burr-Erdős conjecture

Let be a graph. The Ramsey number is the smallest such that whenever you color the edges of the complete graph with vertices with two colors blue and red, you can either find a blue copy or a red copy … Continue reading

Posted in Combinatorics, Updates | Tagged , | 1 Comment

More Reasons for Small Influence

Readers of the big-league ToC blogs have already heard about the breakthrough paper An average-case depth hierarchy theorem for Boolean circuits by Benjamin Rossman, Rocco Servedio, and Li-Yang Tan. Here are blog reports on Computational complexity, on the Shtetl Optimized, and of Godel … Continue reading

Posted in Combinatorics, Computer Science and Optimization, Open problems, Probability | 12 Comments

My Fest

It is a pleasure to announce my own birthday conference which will take place in Jerusalem on June 15-16 2015. Here is the meeting’s homepage! The organizers asked me also to mention that some support for accommodation in Jerusalem for the … Continue reading

Posted in Combinatorics, Conferences, Updates | 4 Comments

New Isoperimetric Results for Testing Monotonicity

Muli, Dor and Subash, Jerusalem May 21 2015.   Michel Talagrand            Gregory Margulis Property testing In this post I will tell you about a new paper by Subhash Khot, Dor Minzer and Muli Safra  entitled: On … Continue reading

Posted in Combinatorics, Computer Science and Optimization | 1 Comment

Two Delightful Major Simplifications

Arguably mathematics is getting harder, although some people claim that also in the old times parts of it were hard and known only to a few experts before major simplifications had changed  matters. Let me report here about two recent remarkable simplifications … Continue reading

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The Simplex, the Cyclic polytope, the Positroidron, the Amplituhedron, and Beyond

A quick schematic road-map to these new geometric objects. The  positroidron can be seen as a cellular structure on the nonnegative Grassmanian – the part of the real Grassmanian G(m,n) which corresponds to m by n matrices with all m by … Continue reading

Posted in Algebra and Number Theory, Combinatorics, Convex polytopes, Physics | Tagged , , , , , , | 1 Comment

From Oberwolfach: The Topological Tverberg Conjecture is False

The topological Tverberg conjecture (discussed in this post), a holy grail of topological combinatorics, was refuted! The three-page paper “Counterexamples to the topological Tverberg conjecture” by Florian Frick gives a brilliant proof that the conjecture is false. The proof is … Continue reading

Posted in Combinatorics, Conferences, Convexity, Updates | Tagged , , | 2 Comments

Midrasha Mathematicae #18: In And Around Combinatorics

  Tahl Nowik                  Update 3 (January 30): The midrasha ended today. Update 2 (January 28): additional videos are linked; Update 1 (January 23): Today we end the first week of the school. David Streurer and Peter Keevash completed … Continue reading

Posted in Combinatorics, Conferences, Updates | 1 Comment

When Do a Few Colors Suffice?

When can we properly color the vertices of a graph with a few colors? This is a notoriously difficult problem. Things get a little better if we consider simultaneously a graph together with all its induced subgraphs. Recall that an … Continue reading

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