Monthly Archives: February 2021

To cheer you up in difficult times 21: Giles Gardam lecture and new result on Kaplansky’s conjectures

Posted on February 25, 2021 by Gil Kalai

There is a very famous conjecture of Irving Kaplansky that asserts that the group ring of a torsion free group does not have zero-divisors. Given a group G and a ring R, the group ring R[G] consists of formal (finite) … Continue reading →

Posted in Algebra | Tagged , | 8 Comments

Nostalgia corner: John Riordan’s referee report of my first paper

Posted on February 19, 2021 by Gil Kalai

In 1971/1972 academic year, I was an undergraduate student at the Hebrew University of Jerusalem and toward the end of the year I wrote a paper about Abel’s sums. I sent it to John Riordan the author of the books  … Continue reading →

Posted in Combinatorics, personal | Tagged , , , | 8 Comments

At the Movies III: Picture a Scientist

Posted on February 18, 2021 by Gil Kalai

A few days ago I saw the great, emotionally steering, movie Picture a Scientist. I strongly recommend it. Here is the link to the  hompage trailer, and IMBd page. SYNOPSIS PICTURE A SCIENTIST chronicles the groundswell of researchers who are … Continue reading →

Posted in Movies, Women in science | Tagged , , , , | 2 Comments

At the Movies II: Kobi Mizrahi’s short movie White Eye makes it to the Oscar’s short list.

Posted on February 17, 2021 by Gil Kalai

Update:  White eye have made it to the list of five Oscar candidates! Congratulations! My nephew Kobi Mizrahi is a well known movie producer and it was just announced that his short film “White eye” (עין לבנה) made it to … Continue reading →

Posted in Movies, People, personal | Tagged , | Leave a comment

And the Oscar goes to: Meir Feder, Zvi Reznic, Guy Dorman, and Ron Yogev

Posted on February 16, 2021 by Gil Kalai

My mother Carmela Kalai often said that if there was something she is thankful for it was that she was born in the era of movies. Indeed, she loved movies from a very early age throughout her life.  So, I … Continue reading →

Posted in Computer Science and Optimization, Information theory, Movies | Tagged , , , | 1 Comment

Thomas Vidick: What it is that we do

Posted on February 15, 2021 by Gil Kalai

Originally posted on MyCQstate:
This post is a follow-up on some somewhat off-hand comments that I made earlier regarding the notion of truth in a “proof-based” discipline such as pure mathematics or theoretical computer science. Since the former is easier…

Posted in What is Mathematics | Tagged | 1 Comment

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)

Posted on February 8, 2021 by Gil Kalai

What will be the next polymath project? click here for our post about it.  New lower bounds for van der Waerden numbers by Ben Green Abstract: We show that there is a red-blue colouring of [N] with no blue 3-term … Continue reading →

Posted in Combinatorics, Number theory | Tagged , | 4 Comments

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

Posted on February 3, 2021 by Gil Kalai

What will be the next polymath project? click here for our previous post.  Number on the forehead, communication complexity, and additive combinatorics Larger Corner-Free Sets from Better NOF Exactly-N Protocols, by Nati Linial and Adi Shraibman Abstract: A subset of … Continue reading →

Posted in Combinatorics, Computer Science and Optimization | Tagged , | 3 Comments