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Recent Posts
- To cheer you up in difficult times 21: Giles Gardam lecture and new result on Kaplansky’s conjectures
- Nostalgia corner: John Riordan’s referee report of my first paper
- At the Movies III: Picture a Scientist
- At the Movies II: Kobi Mizrahi’s short movie White Eye makes it to the Oscar’s short list.
- And the Oscar goes to: Meir Feder, Zvi Reznic, Guy Dorman, and Ron Yogev
- Thomas Vidick: What it is that we do
- To cheer you up in difficult times 20: Ben Green presents super-polynomial lower bounds for off-diagonal van der Waerden numbers W(3,k)
- To cheer you up in difficult times 19: Nati Linial and Adi Shraibman construct larger corner-free sets from better numbers-on-the-forehead protocols
- Possible future Polymath projects (2009, 2021)
Top Posts & Pages
- To cheer you up in difficult times 21: Giles Gardam lecture and new result on Kaplansky's conjectures
- The Argument Against Quantum Computers - A Very Short Introduction
- Possible future Polymath projects (2009, 2021)
- 8866128975287528³+(-8778405442862239)³+(-2736111468807040)³
- TYI 30: Expected number of Dice throws
- Photonic Huge Quantum Advantage ???
- Jean
- ICM 2018 Rio (3) - Coifman, Goldstein, Kronheimer and Mrowka, and the Four Color Theorem
- Dan Romik on the Riemann zeta function
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Monthly Archives: August 2017
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