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 Amazing: Stefan Glock, Daniela Kühn, Allan Lo, and Deryk Osthus give a new proof for Keevash’s Theorem. And more news on designs.
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 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.
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 Benoît's Fractals
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 Amazing: Stefan Glock, Daniela Kühn, Allan Lo, and Deryk Osthus give a new proof for Keevash's Theorem. And more news on designs.
 Stefan Steinerberger: The Ulam Sequence
 Amazing: Peter Keevash Constructed General Steiner Systems and Designs
 Believing that the Earth is Round When it Matters
 Polymath10: The Erdos Rado Delta System Conjecture
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Monthly Archives: June 2009
Test Your Intuition (6)
This is not as clear cut a question as the earlier ones, and if you do not know an answer then it will be difficult to figure one out just based on intuition. (But perhaps possible). If you are intrigued by … Continue reading
Praise For ‘Gina says’
Praise for: ” ‘Gina Says,’ Adventures in the Blogsphere String War (Below the dividing line: Greg Kuperberg, Scott Aaronson, Clifford Johnson, Peter Woit, Motty Perry, Caterina Calsamiglia, Yuval Peres, Eva Illouz, and (right from the comment section) Luca Trevisan, Thomas … Continue reading
Posted in Book review, Gina Says
11 Comments
My Book: “Gina Says,” Adventures in the Blogosphere String War
I wrote a book. It is a sort of a popular science book and it is also about blogging and debating. You can download the first part of the book : It is a 94 page pdf file. “Gina Says,” Adventures in … Continue reading
Posted in Blogging, Gina Says
35 Comments
A Little Story Regarding Borsuk’s Conjecture
Jeff Kahn Jeff and I worked on the problem for several years. Once he visited me with his family for two weeks. Before the visit I emailed him and asked: What should we work on in your visit? Jeff asnwered: … Continue reading
Borsuk’s Conjecture
Karol Borsuk conjectured in 1933 that every bounded set in can be covered by sets of smaller diameter. Jeff Kahn and I found a counterexample in 1993. It is based on the FranklWilson theorem. Let be the set of vectors of length . … Continue reading
Banknotes with Pictures of Mathematicians
Are you aware of any? (current ones? old ones?)
Posted in Uncategorized
12 Comments
Test Your Intuition (5)
(Not such a set) consider a planar set A with the following property. In every direction, the distance between the two parallel lines that touch A from both sides is the same! Must A be a circle?
Answer To Test Your Intuition (4)
Let G be a graph and u and v two vertices. (1) Let H be a random graph where every edge of G is chosen with probability ½. Let p be the probability that there is a path between u … Continue reading
Test Your Intuition (4)
Let G be a graph and u and v two vertices. (1) Let H be a random graph where every edge of G is chosen with probability ½. Let p be the probability that there is a path between u … Continue reading
Posted in Probability
18 Comments