roulette prior

It being Spring Break here at NYU, the plan was to get one paper done per day! So far: Four days, zero papers. Damn.

Bovy and I spent the day hacking and talking on the dynamical inference problem: Determine the parameters of the gravitational potential given a snapshot of test particle positions and velocities. As I have noted previously, this problem is ill-posed in general; it all comes down to priors. Today we decided to revive our old idea of the roulette prior, or the prior that leads to a flat posterior distribution for particle phases (in the language you can use for integrable potentials; there are generalizations for non-integrable). We got talked out of that prior by Tremaine, but I now think for the wrong reasons; we certainly didn't understand the problem as well back then.