Chang was appointed assistant professor at the State University of New York at Buffalo, 1974-1975. Then Hedrick Assistant Professor at the University of California at Los Angeles until 1977 when she moved to the University of Maryland as an assistant professor. A Sloan Fellow, 1979-1980.
Returned 1980 to the University of California at Los Angeles as an associate professor, later promoted to full professor. Invited speaker at the International Congress of Mathematicians at Berkeley in 1986. During 1988-1989 also a full professor at the University of California, Berkeley.
Chang's research interests include the study of certain geometric types of nonlinear partial differential equations. Also the related extremal inequalities and problems in isospectral geometry.
Perhaps Chang's greatest honour was the 1995 Ruth Lyttle Satter Prize in Mathematics, awarded every two years to a womanwho has made an outstanding contribution to mathematics research in the previous five years. The award is valued at $4,000. The citation for the prize read:-
The Ruth Lyttle Satter Prize is awarded to Sun-Yung Alice Chang for her deep contributions to the study of partial differential equations on Riemannian manifolds and in particular for her work on extremal problems in spectral geometry and the compactness of isospectral metrics within a fixed conformal class on a compact 3-manifold.On receiving the prize Chang spoke about her work (see [1]):-
It is an honor for me to receive the prize. Since all the work cited above is joint work with my coauthors (Paul Yang for the most part, but also Tom Branson and Matt Gursky), I would like to express my indebtedness to them.Chang also spoke about the position of women in mathematics research and how things are changing rapidly:-The problems which I have been working on in the past few years are mainly connected with the study of extremal functions of Sobolev inequalities. Such functions play an important role in the study of the blow-up phenomenon in a number of problems in geometry. Following the early work of J Moser and influenced by the work of T Aubin and R Schoen on the Yamabe problem, P. Yang and I have solved the partial differential equation of Gaussian/scalar curvatures on the sphere by studying the extremal functions for certain variation functionals. We have also applied this approach in conformal geometry to the isospectral compactness problem on 3-manifolds when the metrics are restricted in any given conformal class. More recently we have been studying the extremal metrics for these functionals. We are working to derive further geometric consequences. This latter piece of work is a natural extension of the earlier work by Osgood-Phillips-Sarnak on the log-determinant functional on compact surfaces.
Since the Satter Prize is an award for women mathematicians, one cannot help but to reflect on the status of women in our profession now. Compared to the situation when I was a student, it is clear that there are now many more active women research mathematicians. I can personally testify to the importance of having role models and the companionship of other women colleagues. However, I think we need even more women mathematicians to prove good theorems and to contribute to the profession.