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 Polymath10post 4: Back to the drawing board?
 News (mainly polymath related)
 Polymath 10 Post 3: How are we doing?
 Polymath10, Post 2: Homological Approach
 Polymath10: The Erdos Rado Delta System Conjecture
 Convex Polytopes: Seperation, Expansion, Chordality, and Approximations of Smooth Bodies
 Igor Pak’s collection of combinatorics videos
 EDP Reflections and Celebrations
 Séminaire N. Bourbaki – Designs Exist (after Peter Keevash) – the paper
Top Posts & Pages
 Polymath10post 4: Back to the drawing board?
 News (mainly polymath related)
 Polymath 10 Post 3: How are we doing?
 Polymath10: The Erdos Rado Delta System Conjecture
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 (Eran Nevo) The gConjecture I
 Believing that the Earth is Round When it Matters
 The KadisonSinger Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava
 Gödel, Hilbert and Brouwer
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Category Archives: Combinatorics
When Do a Few Colors Suffice?
When can we properly color the vertices of a graph with a few colors? This is a notoriously difficult problem. Things get a little better if we consider simultaneously a graph together with all its induced subgraphs. Recall that an … Continue reading
Coloring Simple Polytopes and Triangulations
Coloring Edgecoloring of simple polytopes One of the equivalent formulation of the fourcolor theorem asserts that: Theorem (4CT) : Every cubic bridgeless planar graph is 3edge colorable So we can color the edges by three colors such that every two … Continue reading
A lecture by Noga
Noga with Uri Feige among various other heroes A few weeks ago I devoted a post to the 240summit conference for Péter Frankl, Zoltán Füredi, Ervin Győri and János Pach, and today I will bring you the slides of Noga … Continue reading
Posted in Combinatorics, Conferences
Tagged Ankur Moitra, Benny Sudakov, Ervin Győri, János Pach, Noga Alon, Peter Frankl, Zoltán Füredi
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Jim Geelen, Bert Gerards, and Geoﬀ Whittle Solved Rota’s Conjecture on Matroids
Gian Carlo Rota Rota’s conjecture I just saw in the Notices of the AMS a paper by Geelen, Gerards, and Whittle where they announce and give a high level description of their recent proof of Rota’s conjecture. The 1970 conjecture asserts … Continue reading
Posted in Combinatorics, Open problems, Updates
Tagged Bert Gerards, Eric Katz, Geoﬀ Whittle, Gian Carlo Rota, Jim Geelen, June Huh, Matroids
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My Mathematical Dialogue with Jürgen Eckhoff
Jürgen Eckhoff, Ascona 1999 Jürgen Eckhoff is a German mathematician working in the areas of convexity and combinatorics. Our mathematical paths have met a remarkable number of times. We also met quite a few times in person since our first … Continue reading
Posted in Combinatorics, Convex polytopes, Open problems
Tagged Andy Frohmader, Helly's theorem, Jurgen Eckhoff, Nina Amenta, Noga Alon, Roy Meshulam
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Happy Birthday Richard Stanley!
This week we are celebrating in Cambridge MA , and elsewhere in the world, Richard Stanley’s birthday. For the last forty years, Richard has been one of the very few leading mathematicians in the area of combinatorics, and he found deep, profound, and … Continue reading
Influence, Threshold, and Noise
My dear friend Itai Benjamini told me that he won’t be able to make it to my Tuesday talk on influence, threshold, and noise, and asked if I already have the slides. So it occurred to me that perhaps … Continue reading
Levon Khachatrian’s Memorial Conference in Yerevan
Workshop announcement The National Academy of Sciences of Armenia together American University of Armenia are organizing a memorial workshop on extremal combinatorics, cryptography and coding theory dedicated to the 60th anniversary of the mathematician Levon Khachatrian. Professor Khachatrian started his … Continue reading
Amazing: Peter Keevash Constructed General Steiner Systems and Designs
Here is one of the central and oldest problems in combinatorics: Problem: Can you find a collection S of qsubsets from an nelement set X set so that every rsubset of X is included in precisely λ sets in the collection? … Continue reading