The APDE seminar on Monday, 4/3, will be given by Jared Wunsch (Northwestern) in-person in Evans 732, 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: Wave propagation on rotating cosmic string backgrounds

Abstract: A rotating cosmic string spacetime has a singularity along a timelike curve corresponding to a one-dimensional source of angular momentum. Such spacetimes are not globally hyperbolic: there exist closed timelike curves near the “string”. Nonetheless, I will describe joint work with Katrina Morgan in which we explore the possibility of obtaining forward solutions to the wave equation, appropriately interpreted.