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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.
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
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 The Erdős Szekeres polygon problem – Solved asymptotically by Andrew Suk.
 The Quantum Computer Puzzle @ Notices of the AMS
 Three Conferences: Joel Spencer, April 2930, Courant; Joel Hass May 2022, Berkeley, Jean Bourgain May 2124, IAS, Princeton
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 Stefan Steinerberger: The Ulam Sequence
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 Polymath 10 Emergency Post 5: The ErdosSzemeredi Sunflower Conjecture is Now Proven.
 A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
 Polymath 10 post 6: The ErdosRado sunflower conjecture, and the Turan (4,3) problem: homological approaches.
 Believing that the Earth is Round When it Matters
 Mind Boggling: Following the work of Croot, Lev, and Pach, Jordan Ellenberg settled the cap set problem!
 The Erdős Szekeres polygon problem  Solved asymptotically by Andrew Suk.
 Polymath10, Post 2: Homological Approach
 Amazing: Peter Keevash Constructed General Steiner Systems and Designs
 Polymath10post 4: Back to the drawing board?
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Category Archives: Test your intuition
Test Your Intuition (15): Which Experiment is More Convincing
Consider the following two scenarios (1) An experiment tests the effect of a new medicine on people which have a certain illness. The conclusion of the experiment is that for 5% of the people tested the medication led to improvement while for … Continue reading
Posted in Statistics, Test your intuition
21 Comments
Discrepancy, The BeckFiala Theorem, and the Answer to “Test Your Intuition (14)”
The Question Suppose that you want to send a message so that it will reach all vertices of the discrete dimensional cube. At each time unit (or round) you can send the message to one vertex. When a vertex gets the … Continue reading
Test Your Intuition (14): A Discrete Transmission Problem
Recall that the dimensional discrete cube is the set of all binary vectors ( vectors) of length n. We say that two binary vectors are adjacent if they differ in precisely one coordinate. (In other words, their Hamming distance is 1.) This … Continue reading
Test Your Intuition (13): How to Play a Biased “Matching Pennies” Game
Recall the game “matching pennies“. Player I has to chose between ‘0’ or ‘1’, player II has to chose between ‘0’ and ‘1’.No player knows what is the choice of the other player before making his choice. Player II pays … Continue reading
False Beliefs in Mathematics
Test your intuition: For two n by n matrices A and B, is it always the case that tr(ABAB) = tr(ABBA)?
Posted in Mathematics over the Internet, Test your intuition
Tagged Mathoverflow, Test your intuition
6 Comments
Test Your Intuition (12): Perturbing a Polytope
Let P be a ddimensional convex polytope. Can we always perturb the vertices of P moving them to points with rational coordinates without changing the combinatorial structure of P? In order words, you require that a set of vertices whose … Continue reading
Posted in Convex polytopes, Test your intuition
Tagged Convex polytopes, Test your intuition
4 Comments
Test Your Intuition (11): Is it Rational to Insure a Toaster
Here is a question from last year’s exam in the course “Basic Ideas of Mathematics”: You buy a toaster for 200 NIS ($50) and you are offered one year of insurance for 24 NIS ($6). a) Is it … Continue reading
Posted in Probability, Rationality, Teaching, Test your intuition
Tagged Insurance, Test your intuition
18 Comments
Test Your Intuition (10): How Does “Random Noise” Look
This is a bit unusual post in the “test your intuition” corner as the problem is not entirely formal. How does random noise in the digital world typically look? Suppose you have a memory of n bits, or a memory based on a larger … Continue reading
Answer to Test Your Intuition (9)
Two experimental results of 10/100 and 15/100 are not equivalent to one experiment with outcomes 3/200. (Here is a link to the original post.) One way to see it is to think about 100 experiments. The outcomes under the null … Continue reading
Buffon’s Needle and the Perimeter of Planar Sets of Constant Width
Here is an answer to “Test your intuition (8)”. (Essentially the answer posed by David Eppstein.) (From Wolfram Mathworld) Buffon’s needle problem asks to find the probability that a needle of length will land on a line, given a floor … Continue reading