The APDE seminar on Monday, 3/4, will be given by John Anderson (Stanford) in-person in **Evans 740,** and will also be broadcasted online via Zoom from **4:10pm to 5:00pm PST**. To participate, please email Federico Pasqualotto (fpasqualotto@berkeley.edu) or Mengxuan Yang (mxyang@math.berkeley.edu).

**Title:** Shock formation for the Einstein–Euler system

**Abstract:** In this talk, I hope to describe elements of proving a certain stable singularity formation result for the Einstein-Euler system, which is the topic of work in progress with Jonathan Luk. I’ll first describe some motivating phenomena. Then, I will describe some of the main mathematical difficulties which present themselves when studying multidimensional shocks and why it is appropriate to call this a shock formation result. Finally, I will try to describe some of the main ideas that go into mathematically understanding shock formation, and the main difficulty in the case of Einstein–Euler.