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 AlexFest: 60 Faces of Groups
 Postoctoral Positions with Karim and Other Announcements!
 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.
Top Posts & Pages
 The Simplex, the Cyclic polytope, the Positroidron, the Amplituhedron, and Beyond
 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
 Believing that the Earth is Round When it Matters
 AlexFest: 60 Faces of Groups
 AviFest, AviStories and Amazing Cash Prizes.
 Sarkaria's Proof of Tverberg's Theorem 1
 Updates and plans III.
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
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Category Archives: Combinatorics
Three Conferences: Joel Spencer, April 2930, Courant; Joel Hass May 2022, Berkeley, Jean Bourgain May 2124, IAS, Princeton
Dear all, I would like to advertise three promisingtobe wonderful mathematical conferences in the very near future. Quick TYI. See if you can guess the title and speaker for a lecture described by “where the mathematics of Cauchy, Fourier, Sobolev, … Continue reading
Posted in Analysis, Combinatorics, Conferences, Geometry, Updates
Tagged Jean Bourgain, Joel Hass, Joel Spencer
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TYI 26: Attaining the Maximum
(Thanks, Dani!) Given a random sequence , ******, , let . and assume that . What is the probability that the maximum value of is attained only for a single value of ? Test your intuition: is this probability bounded … Continue reading
A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
Maryna Viazovska The news Maryna Viazovska has solved the densest packing problem in dimension eight! Subsequently, Maryna Viazovska with Henry Cohn, Steve Miller, Abhinav Kumar, and Danilo Radchenko solved the densest packing problem in 24 dimensions! Here are the links to … Continue reading
Polymath10post 4: Back to the drawing board?
It is time for a new polymath10 post on the ErdosRado Sunflower Conjecture. (Here are the links for post1, post2, post3.) Let me summarize the discussion from Post 3 and we can discuss together what directions to peruse. It is … Continue reading
News (mainly polymath related)
Update (Jan 21) j) Polymath11 (?) Tim Gowers’s proposed a polymath project on Frankl’s conjecture. If it will get off the ground we will have (with polymath10) two projects running in parallel which is very nice. (In the comments Jon Awbrey gave … Continue reading
Polymath 10 Post 3: How are we doing?
The main purpose of this post is to start a new research thread for Polymath 10 dealing with the ErdosRado Sunflower problem. (Here are links to post 2 and post 1.) Here is a very quick review of where we … Continue reading
Posted in Combinatorics, Mathematics over the Internet, Open problems, Polymath10
Tagged polymath10, sunflower conjecture
103 Comments
Polymath10, Post 2: Homological Approach
We launched polymath10 a week ago and it is time for the second post. In this post I will remind the readers what the ErdosRado Conjecture and the ErdosRado theorem are, briefly mention some points made in the previous post and in … Continue reading
Polymath10: The Erdos Rado Delta System Conjecture
The purpose of this post is to start the polymath10 project. It is one of the nine projects (project 3d) proposed by Tim Gowers in his post “possible future polymath projects”. The plan is to attack ErdosRado delta system conjecture also known as the … Continue reading
Posted in Combinatorics, Polymath10
Tagged Alexandr Kostochka, Joel Spencer, Paul Erdos, Richard Rado
138 Comments
Convex Polytopes: Seperation, Expansion, Chordality, and Approximations of Smooth Bodies
I am happy to report on two beautiful results on convex polytopes. One disproves an old conjecture of mine and one proves an old conjecture of mine. Loiskekoski and Ziegler: Simple polytopes without small separators. Does LiptonTarjan’s theorem extends to high … Continue reading
Igor Pak’s collection of combinatorics videos
The purpose of this short but valuable post is to bring to your attention Igor Pak’s Collection of Combinatorics Videos