Category Archives: Combinatorics

Problems for Imre Bárány’s Birthday!

  On June 18-23 2017 we will celebrate in Budapest the 70th birthday of Imre Bárány. Here is the webpage of the conference. For the occasion I wrote a short paper with problems in discrete geometry, mainly around Helly’s and … Continue reading

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Jozsef Solymosi is Giving the 2017 Erdős Lectures in Discrete Mathematics and Theoretical Computer Science

                            May 4 2:30-3:30; May 7 11:00-13:00; May 10 10:30-12:00 See the event webpage for titles and abstracts (or click on the picture below).  

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Updates (belated) Between New Haven, Jerusalem, and Tel-Aviv

This is a (very much) belated update post from the beginning of March (2016). New Haven I spent six weeks in February (2016) in New Haven. It was very nice to get back to Yale after more than two years. Here … Continue reading

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Oded Goldreich Fest

Update (April 17): Outcomes of the poll for the coolest title are in. (See the end of the post) Oded Goldreich’s 60 birthday meeting, April 19-20 at the Weitzmann Institute promises to be a great event. Here is the webpage … Continue reading

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Around the Garsia-Stanley’s Partitioning Conjecture

  Art Duval, Bennet Goeckner, Carly Klivans, and Jeremy Martin found a counter example to the Garsia-Stanley partitioning conjecture for Cohen-Macaulay complexes. (We mentioned the conjecture here.)  Congratulations Art, Bennet, Carly and Jeremy!  Art, Carly, and Jeremy also wrote an article on the … Continue reading

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R(5,5) ≤ 48

The Ramsey numbers R(s,t) The Ramsey number R(s, t) is defined to be the smallest n such that every graph of order n contains either a clique of s vertices or an independent set of t vertices. Understanding the values … Continue reading

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Test Your Intuition (27) about the Alon-Tarsi Conjecture

On the occasion of Polymath 12 devoted to the Rota basis conjecture let me remind you about the Alon-Tarsi conjecture and test your intuition concerning a strong form of the conjecture. The sign of a Latin square is the product … Continue reading

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Thilo Weinert: Transfinite Ramsey Numbers

This is first of three posts kindly written by Thilo Weinert Recently Gil asked me whether I would like to contribute to his blog and I am happy to do so. I enjoy both finite and infinite combinatorics and it … Continue reading

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Timothy Chow Launched Polymath12 on Rota Basis Conjecture and Other News

Polymath12 Timothy Chow launched polymath12 devoted to the Rota Basis conjecture on the polymathblog. A classic paper on the subject is the 1989 paper by Rosa Huang and Gian Carlo-Rota. Let me mention a strong version of Rota’s conjecture (Conjecture … Continue reading

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Proof By Lice!

From camels to lice. (A proof promised here.) Theorem (Hopf and Pannwitz, 1934): Let be a set of points in the plane  in general position (no three points on a line) and consider line segments whose endpoints are in .  Then … Continue reading

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