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Category Archives: Combinatorics
Some Mathematical Puzzles that I encountered during my career
Recently, I gave some general-audience personal tour across four (plus one) mathematical puzzles that I encountered during my career. Here is a paper which is meant for a very wide audience (in English) Puzzles on trees, high dimensions, elections, computation … Continue reading
Elchanan Mossel’s Amazing Dice Paradox (your answers to TYI 30)
TYI 30 asked Elchanan Mossel’s Amazing Dice Paradox (that I heard from Yuval Peres yesterday) You throw a die until you get 6. What is the expected number of throws (including the throw giving 6) conditioned on the event that all throws … Continue reading
Posted in Combinatorics, Probability, Test your intuition
Tagged condition probability, Elchanan Mossel
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TYI 30: Expected number of Dice throws
Test your intuition: You throw a dice until you get 6. What is the expected number of throws (including the throw giving 6) conditioned on the event that all throws gave even numbers. follow-up post
Test your intuition 29: Diameter of various random trees
Both trees in general and random trees in particular are wonderful objects. And there is nothing more appropriate to celebrate Russ Lyons great birthday conference “Elegance in Probability” (taking place now in Tel Aviv) than to test your intuition, dear … Continue reading
Posted in Combinatorics, Probability, Test your intuition
Tagged Russ Lyons, Test your intuition
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Micha Perles’ Geometric Proof of the Erdos-Sos Conjecture for Caterpillars
A geometric graph is a set of points in the plane (vertices) and a set of line segments between certain pairs of points (edges). A geometric graph is simple if the intersection of two edges is empty or a vertex … Continue reading
Touching Simplices and Polytopes: Perles’ argument
Joseph Zaks (1984), picture taken by Ludwig Danzer (OberWolfach photo collection) The story I am going to tell here was told in several places, but it might be new to some readers and I will mention my own angle, … Continue reading
Posted in Combinatorics, Convex polytopes, Geometry, Open problems
Tagged Joseph Zaks, Micha A. Perles
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Where were we?
I was slow blogging, and catching up won’t be so easy. Of course, this brings me back to the question of what I should blog about. Ideally, I should tell you about mathematical things I heard about. The problem is … Continue reading
Jozsef Solymosi is Giving the 2017 Erdős Lectures in Discrete Mathematics and Theoretical Computer Science
May 4 2:30-3:30; May 7 11:00-13:00; May 10 10:30-12:00 See the event webpage for titles and abstracts (or click on the picture below).
Updates (belated) Between New Haven, Jerusalem, and Tel-Aviv
This is a (very much) belated update post from the beginning of March (2016). New Haven I spent six weeks in February (2016) in New Haven. It was very nice to get back to Yale after more than two years. Here … Continue reading
