review of methods for EPRV

Lily Zhao (Yale) walked Megan Bedell (Flatiron) and me through her summary or review of all the methods that have been submitted to her stellar activity challenge for extreme precision radial velocity spectroscopy. She has made the (very good) decision to organize the methods by the assumptions they make rather than the tools they use. For instance, several use principal components analysis, and several others use Gaussian processes. But if they use them in different places, they are effectively making different assumptions. But of course it isn't easy to take someone else's method and decide what assumptions it is making! So this review of all methods—which started out as just a small, necessary part of her paper about the challenge—is in the end one of the big intellectual achievements of this project. I'm excited about it. I'm rarely this excited about a paper that will have dozens and dozens of authors (although I guess I would make exceptions for this paper and this paper)!