Are there any contemporary monographs on minimax theory$^1$, and if so, what are they?
So far, I have seen minimax theory given some treatment in Theory of Point Estimation by Lehmann and Casella (1998), and a more extensive treatment in Introduction to Nonparametric Estimation by Tsybakov (2009).
With the reservation that I only have terse introductory knowledge of this subject, and that I am at a stage where I don't know what I don't know; it feels like there is a gulf between what is covered on this from the statistical decision theory angle in Lehmann and Casella, compared with more 'modern' papers in statistical machine learning.
To elaborate a little further on what I mean by more 'modern', many of the papers I have had a passing glance at seem to use techniques and results in their arguments which seem alien to what I would call 'classical statistical decision theory', and often these results are seemingly obscure inequalities or theorems that can only be found in other papers, but not monographs I know of.
$^1$ In the sense of 'minimax estimator' and 'minimaxity' in statistical decision theory and statistical machine learning rather than the referent in artifical intelligence and game theory.