Colloquium DATE 2020-09-24¡@16:10-17:00 PLACE ¼Æ¾ÇÀ]3174±Ð«Ç SPEAKER §õ«Û¾È ±Ð±Â¡]»OÆW¤j¾Ç¸ê°T¤uµ{¾Ç¨t¡^ TITLE Non-Asymptotic Analysis of EM in Poisson Inverse Problems ABSTRACT Poisson inverse problems arise in many real-world applications, such as positron emission tomography and astronomical image deblurring. Expectation maximization (EM) is a standard---and perhaps the most popular---approach to solving a Poisson inverse problem. Vardi et al. proved EM asymptotically converges more than three decades ago; however, it was unclear how fast EM converges. In this talk, I will present a non-asymptotic convergence guarantee for EM. Our analysis exploits an interesting connection between EM and a portfolio selection method due to Cover. ¾ÇªÌÂ²¤¶