Xu Yang is a Professor of Mathematics at UC Santa Barbara interested in solving seismic tomography problems to understand more about the physical properties of the earth’s interior. His Hellman Fellowship provided him with critical resources to initiate research collaborations with Stanford University, University of Toronto, and the National University of Singapore. This work advanced important developments of frozen Gaussian approximation theory which provides multi-scale asymptotic algorithms for efficiently solving high-dimensional inverse problems that yield earth imaging both locally and globally. Fellowship funded projects produced eight research papers, supported one Ph.D. candidate and one post doctoral student, and contributed to Dr. Yang’s tenure appointment. They also influenced his current research interest in using machine learning algorithms for seismic tomography.