Just in time for the holidays, Colleen Robichaux and I wrote this paper on positivity of Schubert coefficients. This paper is unlike any other paper I had written, both in the content and the way we obtained the results. To me, writing it was a religious experience. No, no, the paper is paper is still […]
Is there anything new in Enumerative Combinatorics? Most experts would tell you about some interesting new theorems, beautiful bijections, advanced techniques, connections to other areas, etc. Most outsiders would simply scoff, as in “what can possibly be new about a simple act of counting?” In fact, if you ask traditional combinatorialists they...
The readers of this blog know know that I stay away from non-math related discussions. It’s not that I don’t have any political opinions, I just don’t think they are especially valuable or original. I do however get triggered by a clear anti-Semitism, discrimination of Jews by the universities, and by personal disrespect. The story […]
What follows is an unusual story of perseverance. We start with a conjecture and after some plot twists end up discussing the meaning of truth. While the title is a spoiler, you might not be able to guess how we got there… The conjecture The bunkbed conjecture (BBC) is a basic claim about random subgraphs. […]
By and large, math journals treat the authors like a pesky annoyance, sort of the way a local electric company treats its customers. As in — yes, serving you is our business, but if you don’t like our customer service where else are you going to go? Not all editors operate that way, absolutely not […]
In the past two weeks I posted on the arXiv two very different papers. One is in Discrete Geometry (joint with Karim Adiprasito) and another is in Asymptotic Group Theory (joint with Martin Kassabov). Both are fundamentally combinatorial, resolve (or at least advance) some rather old open problems, and leave some room for future work. […]
The equality cases of Stanley inequality are not in the polynomial hierarchy. How come? What does that tell us about geometric inequalities?
As you all know, my field is Combinatorics. I care about it. I blog about it endlessly. I want to see it blossom. I am happy to see it accepted by the broad mathematical community. It’s a joy to see it represented at (most) top universities and recognized with major awards. It’s all mostly good. […]
I am on record of liking the status quo of math publishing. It’s very far from ideal as I repeatedly discuss on this blog, see e.g. my posts on the elitism, the invited issues, the non-free aspect of it in the electronic era, and especially the pay-to-publish corruption. But overall it’s ok. I give it […]
Starting a paper is easy. That is, if you don’t care for the marketing, don’t want to be memorable, and just want to get on with the story and quickly communicate what you have proved. Fair enough. But that only works when your story is very simple, as in “here is a famous conjecture which […]
This might seem like a strange question. A snarky answer would be “everything!” But no, not really everything. Not all math deserves to be published, just like not all math needs to be done. Making this judgement is difficult and goes against the all too welcoming nature of the field. But if you want to […]