Seminars are held on Thursdays from 4:00 - 5:00pm on Zoom unless otherwise noted. For access information, please contact the Math Department.
For questions about the seminar schedule, please contact Chong Jin.
September 12
Dr. Sheng Xu, Princeton University
Maximum likelihood for high-noise group orbit estimation and cryo-EM
Motivated by applications to single-particle cryo-electron microscopy (cryo-EM), we study a problem of group orbit estimation where samples of an unknown signal are observed under uniform random rotations from a rotational group. In high-noise regime, we describe a stratification of the Fisher information eigenvalues according to transcendence degrees in the algebra of group invariants. We relate the critical points of the log-likelihood optimization landscape to those of a sequence of moment matching problems. Some examples including a simplified model of cryo-EM will be discussed