  We discuss eccentricities (ellipticity and triangularity) generated in
nucleus-nucleus and proton-nucleus collisions. We define multi-particle
eccentricities $\epsilon_n\{m\}$ which are associated with the $n'th$ angular
multipole moment for $m$ particles. We show that in the limit of fluctuation
dominance all of the $\epsilon_n\{m\}$'s are approximately equal for $m \ge 4$.
For dynamics linearly responding to these eccentricities such as hydrodynamics
or proposed in this paper weakly interacting field theory, these relations
among eccentricities are translated into relations among flow moments
$v_n\{m\}$. We explicitly demonstrate it with hydrodynamic calculations.
