- Proof By Lice!
- The seventeen camels riddle, and Noga Alon’s camel proof and algorithms
- Edmund Landau and the Early Days of the Hebrew University of Jerusalem
- Boolean Functions: Influence, Threshold, and Noise
- Laci Babai Visits Israel!
- Polymath10 conclusion
- Is Heads-Up Poker in P?
- The Median Game
- International mathematics graduate studies at the Hebrew University of Jerusalem
Top Posts & Pages
- The seventeen camels riddle, and Noga Alon's camel proof and algorithms
- Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
- Proof By Lice!
- Updates and plans III.
- Extremal Combinatorics III: Some Basic Theorems
- Polymath10: The Erdos Rado Delta System Conjecture
- Believing that the Earth is Round When it Matters
- Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
Author Archives: Gil Kalai
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
Three children inherited 17 camels. The will gave one half to one child, one third to a second child and one ninth to the third. The children did not know what to do and a neighbor offered to lend them … Continue reading
Some personal/historical remarks in first minutes of my lecture at 7ECM on July 2016… German-Jewish mathematicians in the early days of the Hebrew University of Jerusalem Being invited to give a plenary lecture at the 7ECM was a great honor … Continue reading
Here is the written version of my address at the 7ECM last July in Berlin. Boolean functions, Influence, threshold, and Noise Trying to follow an example of a 1925 lecture by Landau (mentioned in the lecture), the writing style is very … Continue reading
I am sure that every one of the readers of this blog heard about Laci Babai’s quasi-polynomial algorithm for graph isomorphism and also the recent drama about it: A mistake pointed out by Harald Helfgott, a new sub-exponential but … Continue reading
The Polymath10 project on the Erdos-Rado Delta-System conjecture took place over this blog from November 2015 to May 2016. I aimed for an easy-going project that people could participate calmly aside from their main research efforts and the duration of … Continue reading
Five years ago I wrote a post entitled Is Backgammon in P? It was based on conversations with Peter Bro Miltersen and Uri Zwick (shown together in the above picture) about the computational complexity of computing the values (and equilibrium … Continue reading
Update: Apparently this game was invented already by Douglas Hofstadter who called it “Mediocrity” and it is published in Hofstadter’s book Metamagical Themas: Questing for the Essence of Mind and Pattern. It is also called “Hruska.” (See here and here.) Ehud Friedgut … Continue reading
I am very happy to announce that a Ph. D program in mathematics for international students at the Hebrew University of Jerusalem is now open. Here is the link to the home page. About the program The Einstein Institute of … Continue reading