Math-life balance is a brand new YouTube channel, for which Maria Yakerson interviews mathematicians. The first one is with Inna Zakharevich, and it's a really interesting watch, and different from usual interviews with mathematicians in a very good way!
Alberto Canonaco, Amnon Neeman, Paolo Stellari: Uniqueness of enhancements for derived and geometric categories proves uniqueness of enhancements of derived categories of abelian categories, for all of them. And what's more, they also deal with the "unseparated derived category" of a Grothendieck abelian category, which one can also call "the homotopy category of injectives". So then the intriguing thing happens that there is a recollement involving the derived category, the homotopy category of injectives and the singularity category, where the latter does not have a unique enhancement, but the other two do. Cool!
Formalising mathematics is the course introduction for a course taught by Kevin Buzzard on formalising mathematics in Lean. The workshop is also online already, guiding you through the first steps in Lean.