Monthly Archives: October 2010

The Simonovits-Sos Conjecture was Proved by Ellis, Filmus and Friedgut

Posted on October 25, 2010 by Gil Kalai

Simonovits and Sos asked: Let be a family of graphs with N={1,2,…,n} as the set of vertices. Suppose that every two graphs in the family have a triangle in common. How large can be? (We talked about it in this post.) … Continue reading →

Posted in Combinatorics, Open problems | Tagged , , , | 10 Comments

Polymath3: Polynomial Hirsch Conjecture 4

Posted on October 21, 2010 by Gil Kalai

So where are we? I guess we are trying all sorts of things, and perhaps we should try even more things. I find it very difficult to choose the more promising ideas, directions and comments as Tim Gowers and Terry Tao did so … Continue reading →

Posted in Combinatorics, Convex polytopes, Open problems, Polymath3 | Tagged , | 74 Comments

A New Appearance

Posted on October 19, 2010 by Gil Kalai

I have changed the appearance of the blog. The main feature of the new appearance that I like is that the comments are with the same size fonts as the posts themselves. This is especially useful for the polymath3 posts. … Continue reading →

Posted in Blogging | 7 Comments

Benoît’s Fractals

Posted on October 17, 2010 by Gil Kalai

Mandelbrot set Benoît Mandelbrot passed away a few dayes ago on October 14, 2010. Since 1987, Mandelbrot was a member of the Yale’s mathematics department. This chapterette from my book “Gina says: Adventures in the Blogosphere String War”   about fractals is brought here on this … Continue reading →

Posted in Geometry, Obituary, Physics, Probability | 6 Comments

Budapest, Seattle, New Haven

Posted on October 15, 2010 by Gil Kalai

Here we continue the previous post on Summer 2010 events in Reverse chronological order. Happy birthday Srac In the first week of August we celebrated Endre Szemeredi’s birthday. This was a very impressive conference. Panni, Endre’s wife, assisted by her … Continue reading →

Posted in Blogging, Conferences | Tagged , , , | 8 Comments

Mabruk Elon, India, and More

Posted on October 15, 2010 by Gil Kalai

I am starting this post in Jaipur. My three children are watching a movie in our Jaipur hotel room and I watch them while I begin to write this post. Hagai is in the middle of a long-planned three-month trip … Continue reading →

Posted in Blogging, Conferences | Tagged , , | 9 Comments

Test Your Intuition (13): How to Play a Biased “Matching Pennies” Game

Posted on October 14, 2010 by Gil Kalai

Recall the game “matching pennies“. Player I has to chose between ‘0’ or ‘1’, player II has to chose between ‘0’ and ‘1’.No player knows what is the choice of the other player before making his choice. Player II pays … Continue reading →

Posted in Games, Test your intuition | Tagged | 5 Comments

Polymath3 : Polynomial Hirsch Conjecture 3

Posted on October 10, 2010 by Gil Kalai

Here is the third research thread for the polynomial Hirsch conjecture.  I hope that people will feel as comfortable as possible to offer ideas about the problem we discuss. Even more important, to think about the problem either in the directions suggested by … Continue reading →

Posted in Combinatorics, Convex polytopes, Open problems, Polymath3 | Tagged | 102 Comments

Polymath 3: The Polynomial Hirsch Conjecture 2

Posted on October 3, 2010 by Gil Kalai

Here we start the second research thread about the polynomial Hirsch conjecture.  I hope that people will feel as comfortable as possible to offer ideas about the problem. The combinatorial problem looks simple and also everything that we know about it is rather simple: … Continue reading →

Posted in Convex polytopes, Open problems, Polymath3 | Tagged , | 104 Comments