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Recent Posts
 Hoi Nguyen and Melanie Wood: Remarkable Formulas for the Probability that Projections of Lattices are Surjective
 Petra! Jordan!
 The largest clique in the Paley Graph: unexpected significant progress and surprising connections.
 Thinking about the people of Wuhan and China
 Ringel Conjecture, Solved! Congratulations to Richard Montgomery, Alexey Pokrovskiy, and Benny Sudakov
 Test your intuition 43: Distribution According to Areas in Top Departments.
 Two talks at HUJI: on the “infamous lower tail” and TOMORROW on recent advances in combinatorics
 Amazing: Zhengfeng Ji, Anand Natarajan, Thomas Vidick, John Wright, and Henry Yuen proved that MIP* = RE and thus disproved Connes 1976 Embedding Conjecture, and provided a negative answer to Tsirelson’s problem.
 Do Not Miss: Abel in Jerusalem, Sunday, January 12, 2020
Top Posts & Pages
 Hoi Nguyen and Melanie Wood: Remarkable Formulas for the Probability that Projections of Lattices are Surjective
 Aubrey de Grey: The chromatic number of the plane is at least 5
 Konstantin Tikhomirov: The Probability that a Bernoulli Matrix is Singular
 Elchanan Mossel's Amazing Dice Paradox (your answers to TYI 30)
 Ringel Conjecture, Solved! Congratulations to Richard Montgomery, Alexey Pokrovskiy, and Benny Sudakov
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 A sensation in the morning news  Yaroslav Shitov: Counterexamples to Hedetniemi's conjecture.
 Gil's Collegial Quantum Supremacy Skepticism FAQ
 Coloring Problems for Arrangements of Circles (and Pseudocircles)
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Monthly Archives: September 2019
Test Your Intuition 40: What Are We Celebrating on Sept, 28, 2019? (And answer to TYI39.)
Update: We are celebrating 10 years anniversary to Mathoverflow Domotorp got the answer right. congratulations, Domotorp! To all our readers: Shana Tova Umetuka – שנה טובה ומתוקה – Happy and sweet (Jewish) new year.
Posted in Test your intuition, What is Mathematics
Tagged Mathoverflow, Test your intuition
6 Comments
Quantum computers: amazing progress (Google & IBM), and extraordinary but probably false supremacy claims (Google).
A 2017 cartoon from this post. After the embargo update (Oct 25): Now that I have some answers from the people involved let me make a quick update: 1) I still find the paper unconvincing, specifically, the verifiable experiments (namely experiments … Continue reading
Posted in Combinatorics, Computer Science and Optimization, Quantum, Updates
Tagged John Martinis
67 Comments
Jeff Kahn and Jinyoung Park: Maximal independent sets and a new isoperimetric inequality for the Hamming cube.
Three isoperimetric papers by Michel Talagrand (see the end of the post) Discrete isoperimetric relations are of great interest on their own and today I want to tell you about a new isoperimetric inequality by Jeff Kahn and Jinyoung Park … Continue reading
Alef’s corner: Bicycles and the Art of Planar Random Maps
The artist behind Alef’s corner has a few mathematical designs and here are two new ones. (See Alef’s website offering over 100 Tshirt designs.) which was used for the official Tshirt for JeanFrançois Le Gall’s birthday conference. See also … Continue reading
Paul Balister, Béla Bollobás, Robert Morris, Julian Sahasrabudhe, and Marius Tiba: Flat polynomials exist!
Béla Bollobás and Paul Erdős at the University of Cambridge in 1990. Credit George Csicsery (from the 1993 film “N is a Number”) (source) (I thank Gady Kozma for telling me about the result.) An old problem from analysis with a … Continue reading
Posted in Analysis, Combinatorics
Tagged Béla Bollobás, Flat polynomials, Julian Sahasrabudhe, Marius Tiba, Paul Balister, Robert Morris
1 Comment
Computer Science and its Impact on our Future
A couple of weeks ago I told you about Avi Wigderson’s vision on the connections between the theory of computing and other areas of mathematics on the one hand and between computer science and other areas of science, technology and … Continue reading
Posted in Academics, Computer Science and Optimization, Quantum, Updates
Tagged computer science
1 Comment
Richard Ehrenborg’s problem on spanning trees in bipartite graphs
Richard Ehrenborg with a polyhedron In the Problem session last Thursday in Oberwolfach, Steve Klee presented a beautiful problem of Richard Ehrenborg regarding the number of spanning trees in bipartite graphs. Let be a bipartite graph with vertices on one … Continue reading