- Mathematical Gymnastics
- Media Item from “Haaretz” Today: “For the first time ever…”
- Jim Geelen, Bert Gerards, and Geoﬀ Whittle Solved Rota’s Conjecture on Matroids
- Media items on David, Amnon, and Nathan
- Next Week in Jerusalem: Special Day on Quantum PCP, Quantum Codes, Simplicial Complexes and Locally Testable Codes
- Happy Birthday Ervin, János, Péter, and Zoli!
- My Mathematical Dialogue with Jürgen Eckhoff
- Test Your Intuition (23): How Many Women?
- Happy Birthday Richard Stanley!
Top Posts & Pages
- Believing that the Earth is Round When it Matters
- The Kadison-Singer Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava
- Two Math Riddles
- The Ultimate Riddle
- Why Quantum Computers Cannot Work: The Movie!
- Polymath 8 - a Success!
- New Ramanujan Graphs!
- Meeting with Aram Harrow, and my Lecture on Why Quantum Computers Cannot Work.
- Analysis of Boolean Functions
Monthly Archives: August 2008
2. The connection with Hirsch’s Conjecture The Hirsch Conjecture asserts that the diameter of the graph G(P) of a d-polytope P with n facets is at most n-d. Not even a polynomial upper bound for the diameter in terms of d and … Continue reading
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
1. A pleasant surprise When I worked on the diameter problem for d-polytopes 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
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
And in my office, there is a beautiful autoportrait by my sister Tamar Kalai. (Click for a deatiled picture.)