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 Alexander A. Gaifullin: Many 27vertex Triangulations of Manifolds Like the Octonionic Projective Plane (Not Even One Was Known Before).
 Answer to Test Your Intuition 50: Detecting a Deviator
 To cheer you up in difficult times 36: The Immense Joy of Fake Reverse Parking
 Ordinary computers can beat Google’s quantum computer after all
 Test Your Intuition 50. TwoPlayer Random Walk; Can You Detect Who Did Not Follow the Rules?
 ICM 2022. Kevin Buzzard: The Rise of Formalism in Mathematics
 ICM 2022: Langlands Day
 ICM 2022 awarding ceremonies (1)
 ICM 2022 Virtual Program, Live events, and Dynamics Week in Jerusalem
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 Elchanan Mossel's Amazing Dice Paradox (your answers to TYI 30)
 TYI 30: Expected number of Dice throws
 ICM 2022. Kevin Buzzard: The Rise of Formalism in Mathematics
 Amazing: Hao Huang Proved the Sensitivity Conjecture!
 How Large can a Spherical Set Without Two Orthogonal Vectors Be?
 Amazing: Karim Adiprasito proved the gconjecture for spheres!
 Jim Geelen, Bert Gerards, and Geoﬀ Whittle Solved Rota's Conjecture on Matroids
 To cheer you up in difficult times 34: Ringel Circle Problem solved by James Davies, Chaya Keller, Linda Kleist, Shakhar Smorodinsky, and Bartosz Walczak
 A sensation in the morning news  Yaroslav Shitov: Counterexamples to Hedetniemi's conjecture.
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Monthly Archives: February 2009
Ziegler´s Lecture on the Associahedron
The associahedron in 3 dimension, and James Stasheff. This picture is taken from Bill Casselman’s article on the associahedron. The article is entitled “Strange Associations” and starts with “There are many other polytopes that can be described in purely combinatorial terms. Among the … Continue reading
Posted in Convex polytopes
Tagged Associahedron, Cyclohedron, Permutahedron, Permutoassociahedron
8 Comments
A Little More on Boolean Functions and Bounded Depth Circuits
Boolean circuits This post (in a few parts) contains a quick introduction to Boolean circuits. It is related to the recent news post about the solution of Braverman to the LinialNisan conjecture. In particular, we will describe very quickly a formulation … Continue reading
Posted in Computer Science and Optimization
7 Comments
Rosenfeld’s OddDistance Problem
Moshe Rosenfeld’s odddistance problem: Let G be the graph whose vertices are points in the plane and two vertices form an edge if their distance is an odd integer. Is the chromatic number of this graph finite?
Posted in Combinatorics, Open problems
3 Comments
Which Coalition to Form (2)?
Yair Tauman (This post is a continuation of this previous post.) Aumann and Myerson proposed that if political and ideological matters are put aside, the party forming the coalition would (or should) prefer to form the coalition in which its own power (according … Continue reading
Which Coalition?
The problem. OK, we had an election and have a new parliament with 120 members. The president has asked the leader of one party to form a coalition. (This has not happened yet in the Israeli election but it will happen soon.) Such … Continue reading
Basic Open Research and Failed Institutions – Imagine
Imagine if in the last ten years before the collapse, the huge failed financial and insurance institutions had had independent research units devoted to doing basic, open, and critical research on matters of relevance to the business, ethics, and future of these institutions. Might it have made a small … Continue reading
Majority Rules! – The Story of Achnai’s Oven
It is election day in Israel, and an opportunity to tell the beautiful and moving story of Achnai’s oven. Towards the end of the first century, a few decades after the big Jewish rebellion against the Romans, the sages of the … Continue reading
Posted in Rationality
13 Comments
FranklRodl’s Theorem and Variations on the Cap Set Problem: A Recent Research Project with Roy Meshulam (A)
Voita Rodl I would like to tell you about a research project in progress with Roy Meshulam. (We started it in the summer, but then moved to other things; so far there are interesting insights, and perhaps problems, but not substantial … Continue reading
Posted in Combinatorics, Open problems
Tagged Cap sets, Extremal combinatorics, Intersection theorems, polymath1
10 Comments
Colloquium at Berlin
I arrived to Berlin for a short visit to give a colloquium talk at the new BMS on Hellytype theorems, and to participate in the Ph. D. committee of Ronald Wotzlaw. (Update: Dr. Ronald Wotzlaw.) Here is an abstract for the … Continue reading
Posted in Convexity, Updates
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The HexVotingRule (Not Recommended)
Blue wins – if there is a right to left continuous path of blue regions Red wins – if there is north to south continuous path of red regions (A region is red or blue according to the majority of … Continue reading
Posted in Economics, Games
13 Comments