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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?
- To Cheer You Up in Difficult Times 31: Federico Ardila’s Four Axioms for Cultivating Diversity
- 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
Top Posts & Pages
- Giving a talk at Eli and Ricky's geometry seminar. (October 19, 2021)
- Academic Degrees and Sex
- Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
- The Argument Against Quantum Computers - A Very Short Introduction
- To Cheer You Up in Difficult Times 31: Federico Ardila's Four Axioms for Cultivating Diversity
- Richard Stanley: How the Proof of the Upper Bound Theorem (for spheres) was Found
- To cheer you up in difficult times 32, Annika Heckel's guest post: How does the Chromatic Number of a Random Graph Vary?
- Amazing: Karim Adiprasito proved the g-conjecture for spheres!
- TYI 30: Expected number of Dice throws
Category Archives: Open problems
This post continues to describe problems presented at our open problems session back in November 2020. Here is the first post in the series. Today’s problem was presented by me, and it was an old 1989 conjecture of mine. A … 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
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
Let me briefly report on a remarkable new paper by Esty Kelman, Guy Kindler, Noam Lifshitz, Dor Minzer, and Muli Safra, Revisiting Bourgain-Kalai and Fourier Entropies. The paper describes substantial progress towards the Entropy-Influence conjecture, posed by Ehud Friedgut and … Continue reading
Ringel Conjecture, Solved! Congratulations to Richard Montgomery, Alexey Pokrovskiy, and Benny Sudakov
Ringel’s conjecture solved (for sufficiently large n) A couple weeks ago and a few days after I heard an excellent lecture about it by Alexey Pokrovskiy in Oberwolfach, the paper A proof of Ringel’s Conjecture by Richard Montgomery, Alexey Pokrovskiy, … Continue reading
In the community of mamathetitians in a certain country there are mamathetitians in two areas: Anabra (fraction p of the mamathetitians) and Algasis (fraction 1-p of mamathetitians.) There are ten universities with 50 faculty members in each mamathetics department … Continue reading
Gérard Cornuéjols Gérard Cornuéjols‘s beautiful (and freely available) book from 2000 Optimization: Packing and Covering is about an important area of combinatorics which is lovely described in the preface to the book The integer programming models known as set packing … Continue reading
Richard Ehrenborg with a polyhedron In the Problem session last Thursday in Oberwolfach, Steve Klee presented a beautiful problem of Richard Ehrenborg regarding the number of spanning trees in bipartite graphs. Let be a bipartite graph with vertices on one … Continue reading
Two days ago Nati Linial sent me an email entitled “A sensation in the morning news”. The link was to a new arXived paper by Yaroslav Shitov: Counterexamples to Hedetniemi’s conjecture. Hedetniemi’s 1966 conjecture asserts that if and are two … Continue reading
The high-dimensional conference in Jerusalem is running with many exciting talks (and they are videotaped), and today in Tel Aviv there is a conference on Optimization and Discrete Geometry : Theory and Practice. Today in Jerusalem, Leonard Schulman talked (video available!) … Continue reading