Title: Solvability of the wave equation on rotating cosmic string backgrounds

Abstract: Cosmic strings are solutions to the Einstein equations that have topological defects along one-dimensional ``string" structures. The metric for a rotating cosmic string has interesting features which present challenges for solving the wave equation. It has closed timelike curves and is singular along a timelike line (the ``string"). In the current work, we study wave propagation on such manifolds and use these results to find local forward solutions to the wave equation. This work is joint with Jared Wunsch.

About the Speaker: Katrina Morgan is an NSF RTG Postdoctoral Fellow at Northwestern University.  Before that, she was a Gamelin Postdoctoral Fellow at the MSRI.   She received her Ph.D. in 2019 from the University of North Carolina-Chapel Hill (UNC) under the direction of Jason Metcalfe.  Dr. Morgan’s research interests include nonlinear wave equations, spectral theory, microlocal analysis, and global analysis.  While at UNC, her dissertation work was supported by numerous fellowships, including the highly selective Kenan Graduate Fellowship.  Dr. Morgan is a co-founder of the Girls Talk Math summer day camp for high-schoolers, which has been supported by MAA Tensor grants.  For these efforts, she has received awards from the Association for Women in Mathematics and the UNC Office of the Chancellor.