YTM 2026

Somehow, I never made it to a Young Topologists Meeting before. I came closest 2024, where it happened in Münster, but then I ended up moving to Oslo that summer. As starting a permanent job also meant I was finally beyond any doubt an old topologist, my chances of ever attending a YTM were slim. I was all the more excited when the organizers of this year’s YTM in Copenhagen asked me to be one of the two invited old topologists to give a small lecture series (along with Luciana Bonatto).

So, that happened last week, and it was great! Thanks to the organizers for a fantastic event. Here are notes for my talks. Under the title “Perspectives of Spectra”, I tried to highlight some modern ideas from stable homotopy theory. Originally, the plan was to talk first about the \(\infty\)-category of spectra in general, then cover some of the applications of filtered/synthetic spectra (sort of a condensed version of the course I taught recently), and then spend the third lecture talking about some recent work in progress with Ben Antieau on something we call “Effective Spectra”. Somewhere along the way, I realized that the original plan for Lecture 2 was too ambitious, and so I ended up spending both Lecture 2 and 3 on the synthetic story. I still left the notes on effective spectra which I had prepared in the document, for anyone who was interested in that talk.