Category Archives: Combinatorics

Giving a talk at Eli and Ricky’s geometry seminar. (October 19, 2021)

One of my favorite seminars in the world is the Courant Institute (NYU) Geometry seminar that Eli Goodman and Ricky Pollack started in the 1980s (I think). On Tuesday October 19, I will give a seminar, details follow. Jacob Eli … Continue reading

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To cheer you up in difficult times 32, Annika Heckel’s guest post: How does the Chromatic Number of a Random Graph Vary?

This is a guest post kindly written by Annika Heckel. We first reported about Annika Heckel’s breakthrough in this post. A pdf version of this post can be found here. Pick an -vertex graph uniformly at random. Pick another one. … Continue reading

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To Cheer You Up in Difficult Times 31: Federico Ardila’s Four Axioms for Cultivating Diversity

Todos Cuentan (Everybody counts) In a beautiful NAMS 2016 article Todos Cuentan: Cultivating Diversity in Combinatorics, Federico Ardila put forward four thoughtful axioms which became a useful foundation for Ardila’s own educational and outreach efforts, and were offered as a pressing … Continue reading

Posted in Academics, Combinatorics, What is Mathematics, Women in science | Tagged , | 11 Comments

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

The Simons Institute announces an October 6, 2021 lecture by Irit Dinur with the result in the title. This is a wonderful breakthrough. I am glad to mention that I have altogether 170 combined years of friendships with the authors. … Continue reading

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Let me tell you about three of my recent papers

  Let me tell you briefly about three of my papers that were recently accepted for publication. Relative Leray numbers via spectral sequences with Roy Meshulam, Helly-type problems with Imre Bárány, and Statistical aspects of quantum supremacy experiments with Yosi … Continue reading

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Mathematical news to cheer you up

1.  Anna Kiesenhofer, a PhD mathematician researching PDEs at Ecole Polytechnique Federale Lausanne (EPFL), won the gold medal in the women’s bicycle road race at the Olympics. Here are two trivia question: a) Which hero of a recent post over … Continue reading

Posted in Combinatorics, Sport, Uncategorized, Updates | 5 Comments

To cheer you up in difficult times 26: Two real-life lectures yesterday at the Technion

After 16 months without lecturing to an audience in my same location, I gave yesterday two lectures at the Technion in front of a live audience (and some additional audience in remote locations). The main lecture was in COMSOC 2021, … Continue reading

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To Cheer You Up in Difficult times 24: Borodin’s colouring conjecture!

An acyclic colouring of a graph is a colouring of its vertices so that the subgraph spanned on union of every two colour classes is acyclic (a forest). Grunbaum conjectured in 1973 that Every planar graph has acyclic colouring with … Continue reading

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To cheer you up in difficult times 25: some mathematical news! (Part 2)

Topology Quasi-polynomial algorithms for telling if a knot is trivial Marc Lackenby announced a quasi-polynomial time algorithm to decide whether a given knot is the unknot! This is a big breakthrough. This question is known to be both in NP … Continue reading

Posted in Algebra, Combinatorics, Geometry, Number theory | 2 Comments

Alef Corner: ICM2022

Alef’s new piece for ICM 2022 will surely cheer you up!

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