This post continues our series of online seminars devoted to accessible presentations of some of the most significant mathematical theorems of the 21st century. I am delighted to report that on 1st July 2026, Prof. Oleg Pikhurko delivered a nice and accessible lecture on Squaring the Circle. If you missed the talk, the recording is now available on YouTube.
The next lecture in the series will take place on Prof. Marc Lackenby (University of Oxford, UK) will discuss Reidemeister moves, the elementary transformations that relate different diagrams of the same knot or link, and the question of how efficiently one can pass between such diagrams. The talk will highlight his polynomial bounds for simplifying diagrams of the unknot, and explain recent work extending these ideas to every fixed link type. It will also describe the consequences for the computational complexity of recognizing knots and links.
To join the talk, simply click here at the scheduled time; no registration is required. For a full list of upcoming seminars, please visit https://th21.le.ac.uk/next-talks/.
For announcements of other talks, as well as descriptions of recent major mathematical breakthroughs, see the full list of posts on this blog.
Please have a look at this previous blog post for my detailed description of the topic of this talk.