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- Giving a talk at Eli and Ricky’s geometry seminar. (October 19, 2021)
- To cheer you up in difficult times 32, Annika Heckel’s guest post: How does the Chromatic Number of a Random Graph Vary?
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- Dream a Little Dream: Quantum Computer Poetry for the Skeptics (Part I, mainly 2019)
- To Cheer you up in difficult times 30: Irit Dinur, Shai Evra, Ron Livne, Alex Lubotzky, and Shahar Mozes Constructed Locally Testable Codes with Constant Rate, Distance, and Locality
- To cheer you up in difficult times 29: Free will, predictability and quantum computers
- Alef’s corner: Mathematical research
- Let me tell you about three of my recent papers
- Mathematical news to cheer you up

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- Giving a talk at Eli and Ricky's geometry seminar. (October 19, 2021)
- Academic Degrees and Sex
- The Argument Against Quantum Computers - A Very Short Introduction
- To cheer you up in difficult times 32, Annika Heckel's guest post: How does the Chromatic Number of a Random Graph Vary?
- To Cheer You Up in Difficult Times 31: Federico Ardila's Four Axioms for Cultivating Diversity
- To cheer you up in difficult times 11: Immortal Songs by Sabine Hossenfelder and by Tom Lehrer
- TYI 30: Expected number of Dice throws
- Richard Stanley: How the Proof of the Upper Bound Theorem (for spheres) was Found
- Must-read book by Avi Wigderson

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# Monthly Archives: November 2020

## Recent progress on high dimensional Turan-Type problems by Andrey Kupavskii, Alexandr Polyanskii, István Tomon, and Dmitriy Zakharov and by Jason Long, Bhargav Narayanan, and Corrine Yap.

The extremal number for surfaces Andrey Kupavskii, Alexandr Polyanskii, István Tomon, Dmitriy Zakharov: The extremal number of surfaces Abstract: In 1973, Brown, Erdős and Sós proved that if is a 3-uniform hypergraph on vertices which contains no triangulation of the sphere, then … Continue reading

## Open problem session of HUJI-COMBSEM: Problem #1, Nati Linial – Turan type theorems for simplicial complexes.

On November, 2020 we had a very nice open problem session in our weekly combinatorics seminar at HUJI. So I thought to have a series of posts to describe you the problems presented there. This is the first post in … Continue reading

## Péter Pál Pach and Richárd Palincza: a Glimpse Beyond the Horizon

Prologue Consider the following problems: P3: What is the maximum density of a set A in without a 3-term AP? (AP=arithmetic progression.) This is the celebrated Cap Set problem and we reported here in 2016 the breakthrough results by … Continue reading

Posted in Combinatorics, Geometry, Number theory, Open problems
Tagged Péter Pál Pach, Richárd Palincza
9 Comments

## To cheer you up 14: Hong Liu and Richard Montgomery solved the Erdős and Hajnal’s odd cycle problem

The news: In 1981, Paul Erdős and András Hajnal asked whether the sum of the reciprocals of the odd cycle lengths in a graph with infinite chromatic number is necessarily infinite. Hong Liu and Richard Montgomery have just proved that … Continue reading

Posted in Combinatorics
Tagged András Hajnal, Carsten Thomassen, Hong Liu, Paul Erdos, Richard Montgomry
7 Comments

## To cheer you up in difficult times 13: Triangulating real projective spaces with subexponentially many vertices

Wolfgang Kühnel Today I want to talk about a new result in a newly arXived paper: A subexponential size by Karim Adiprasito, Sergey Avvakumov, and Roman Karasev. Sergey Avvakumov gave about it a great zoom seminar talk about the result … Continue reading

Posted in Algebra, Combinatorics, Geometry
Tagged Karim Adiprasito, Roman Karasev, Sergey Avvakumov, Wolfgang Kuhnel
1 Comment

## Benjamini and Mossel’s 2000 Account: Sensitivity of Voting Schemes to Mistakes and Manipulations

Here is a popular account by Itai Benjamini and Elchanan Mossel from 2000 written shortly after the 2000 US presidential election. Elchanan and Itai kindly agreed that I will publish it here, for the first time, 20 years later! I … Continue reading

Posted in Combinatorics, Games, Probability, Rationality
Tagged Elchanan Mossel, Itai Benjamini
6 Comments