Discussion on 'Nonparametric Estimation of Dark Matter Distributions' by Wang et al

摘要

We consider the question: When should data modeling in astronomy be based on nonparametric vs. parametric modeling techniques? Two historical cases are considered. For understanding binary star and extrasolar planet systems, parametric modeling using well-established theory based on Newtonian gravity is successful and appropriate. For understanding the structure of elliptical galaxies, confusion has persisted for several decades regarding which parametric model is best. Here, where the astrophysical situation is complex and inadequately understood, nonparametric approaches such as those described by Professor Wang are preferred.