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 Reflections: On the Occasion of Ron Adin’s and Yuval Roichman’s Birthdays, and FPSAC 2021
 ICM 2018 Rio (5) Assaf Naor, Geordie Williamson and Christian Lubich
 Test your intuition 47: AGCGTCTGCGTCTGCGACGATC? what comes next in the sequence?
 Cheerful news in difficult times: Richard Stanley wins the Steele Prize for lifetime achievement!
 Combinatorial Theory is Born
 To cheer you up in difficult times 34: Ringel Circle Problem solved by James Davies, Chaya Keller, Linda Kleist, Shakhar Smorodinsky, and Bartosz Walczak
 Good Codes papers are on the arXiv
 To cheer you up in difficult times 33: Deep learning leads to progress in knot theory and on the conjecture that KazhdanLusztig polynomials are combinatorial.
 The Logarithmic Minkowski Problem
Top Posts & Pages
 NavierStokes Fluid Computers
 The Intermediate Value Theorem Applied to Football
 TYI 30: Expected number of Dice throws
 Believing that the Earth is Round When it Matters
 To Cheer You Up in Difficult Times 31: Federico Ardila's Four Axioms for Cultivating Diversity
 Amazing: Karim Adiprasito proved the gconjecture for spheres!
 'Gina Says'
 To cheer you up in difficult times 27: A major recent "Lean" proof verification
 An interview with Noga Alon
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Monthly Archives: September 2008
Extremal Combinatorics III: Some Basic Theorems
. Shattering Let us return to extremal problems for families of sets and describe several basic theorems and basic open problems. In the next part we will discuss a nice proof technique called “shifting” or “compression.” The SauerShelah (Perles VapnikChervonenkis) Lemma: (Here we write .) … Continue reading
New Haven (mainly pictures)
] Yale, New Haven I am back in New Haven which have become my home away from home in the last five years. Cappuccino’S and more – Cedar cross Congress, New Haven. Not only that this name is similar … Continue reading
Posted in Uncategorized
Tagged New Haven, Three dimensional electron microscopy, Yale, Yoel Shkolinsky
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Annotating Kimmo Eriksson’s Poem
“Start counting her NUMBER OF FACES,” Kimmo Eriksson, Brush up your Björner (2008). The time is right to annotate Kimmo Eriksson’s memorable poem: 1. What are Chip firing games? Many women will find it admirable if you tell her she … Continue reading
A Diameter Problem (5)
6. First subexponential bounds. Proposition 1: How to prove it: This is easy to prove: Given two sets and in our family , we first find a path of the form where, and . We let with and consider the family … Continue reading
Diameter Problem (4)
Let us consider another strategy to deal with our diameter problem. Let us try to associate other graphs to our family of sets. Recall that we consider a family of subsets of size of the set . Let us now associate … Continue reading
Diameter Problem (3)
3. What we will do in this post and and in future posts We will now try all sorts of ideas to give good upper bounds for the abstract diameter problem that we described. As we explained, such bounds apply … Continue reading
Posted in Combinatorics, Convex polytopes, Open problems
Tagged Hirsch conjecture, Linear programming, Quasiautomated proofs
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Oded
I just heard the terrible news that Oded Schramm was killed in a hiking accident. Oded was hiking on Guye Peak near Snoqualmie Pass near Seattle. This is a terrible loss to Oded’s family, and our hearts and thoughts are … Continue reading
The Prisoner’s Dilemma, Sympathy, and Yaari’s Challenge
Correlation and Cooperation In our spring school devoted to Arrow’s economics, Menahem Yaari gave a talk entitled “correlation and cooperation.” It was about games as a model of people’s behavior, and Yaari made the following points: It is an empirical fact … Continue reading
Posted in Economics, Games, Philosophy, Rationality
Tagged Cooperation, Correlation, Prisoner dilemma
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