Emmy Noether Lectures

1983 Lecturer: Cathleen Synge Morawetz

How Do Perturbations of the Wave Equation Work

Cathleen Synge Morawetz was born in Toronto of Irish parents. She graduated from the University of Toronto in 1945 and went on to receive her master’s degree at the Massachusetts Institute of Technology. She earned her PhD at New York University, with a thesis on the stability of a spherical implosion. She is a professor at the Courant Institute of Mathematical Sciences at NYU, where she served as director from 1984 to 1988. In 1981, she delivered the Gibbs Lecture of The American Mathematical Society, and in 1982 presented an Invited Address at a meeting of the Society for Industrial and Applied Mathematics. She is a member of the National Academy of Sciences and was named Outstanding Woman Scientist for 1993 by the Association for Women in Science. In 1995, she became the second woman elected to the office of president of the American Mathematical Society.
Morawetz’s earliest published works were on the stability of steady viscous flows. In an early paper, she showed that there are stable modes for many Orr-Somerfeld two-point boundary value problems coming from the perturbation of steady flows, but these modes slip off to infinity in the limit of zero viscosity. As a result, they are of little interest in analyzing viscosity. Turning to the mathematics of transonic flow, she showed that specially designed shockless airfoils develop shocks if they are altered even by a small amount. This discovery opened the problem of developing a theory for a flow with shocks.