The HADES seminar on Tuesday, **September 10th**, will be at **2****:00pm** in **Room 740.**

**Speaker:** Katie Marsden

**Abstract:** This talk will concern the three dimensional half-wave maps equation (HWM), a nonlocal geometric equation with close links to the better-known wave maps equation. In high dimensions, n≥4, HWM is known to admit global solutions for suitably small initial data. The extension of these results to three dimensions presents significant new difficulties due to the loss of a key Strichartz estimate. In this talk I will introduce the half-wave maps equation and discuss a global wellposedness result for the three dimensional problem under an additional assumption of angular regularity on the initial data. The proof combines techniques from the study of wave maps with new microlocal arguments involving commuting vector fields and improved Strichartz estimates.