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 Jirka
 AviFest, AviStories and Amazing Cash Prizes.
 Polymath 10 post 6: The ErdosRado sunflower conjecture, and the Turan (4,3) problem: homological approaches.
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 More Math from Facebook
 The Erdős Szekeres polygon problem – Solved asymptotically by Andrew Suk.
 The Quantum Computer Puzzle @ Notices of the AMS
 Three Conferences: Joel Spencer, April 2930, Courant; Joel Hass May 2022, Berkeley, Jean Bourgain May 2124, IAS, Princeton
Top Posts & Pages
 Believing that the Earth is Round When it Matters
 The Erdős Szekeres polygon problem  Solved asymptotically by Andrew Suk.
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 Polymath10post 4: Back to the drawing board?
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 Polymath 10 post 6: The ErdosRado sunflower conjecture, and the Turan (4,3) problem: homological approaches.
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Monthly Archives: August 2008
A Diameter Problem (2)
2. The connection with Hirsch’s Conjecture The Hirsch Conjecture asserts that the diameter of the graph G(P) of a dpolytope P with n facets is at most nd. Not even a polynomial upper bound for the diameter in terms of d and … Continue reading
Posted in Combinatorics, Convex polytopes, Open problems
5 Comments
Two Very Early Problems, a Simple Solution, and a New Problem
As an undergraduate student whenever I studied some subject I tried to come up with problems. Many of these problems were artificial or silly and, of course, I forgot most of them. But a few still make sense. Here are … Continue reading
Posted in Open problems
9 Comments
Surprising Math
1. A pleasant surprise When I worked on the diameter problem for dpolytopes with n facets. I was aiming to prove an upper bound of the form but my proof only gave It was a pleasant surprise to note that . 2. … Continue reading
Posted in Uncategorized
4 Comments
Plans and Updates
Jerusalem and Budapest Monday, last week was the last day of lectures for the spring term here at the Hebrew U. One outcome of the long professors’ strike was a very fruitful year for research seminars. We ran them during … Continue reading
More Art: Tami’s Autoportrait
And in my office, there is a beautiful autoportrait by my sister Tamar Kalai. (Click for a deatiled picture.)
Our Department’s Quilt
Academic administation is a topic of great interest that desrves a special post. The highest post I served was as the department chair, and one thing I did was to acquire for the department a quilt by the artist Anna Maria … Continue reading