  In a recent paper with Thomas Hoffmann-Ostenhof, we proved that the number of
critical points in the boundary set of a k-minimal partition tends to infinity
as k tends to infinity. In this note, we show that this number increases
linearly with k as suggested by a hexagonal conjecture about the asymptotic
behavior of the energy of these minimal partitions. As the original proof by
Pleijel, this involves Faber-Krahn's inequality and Weyl's formula, but this
time, due to the magnetic characterization of the minimal partitions, we have
to establish a Weyl's formula for Aharonov-Bohm operator controlled with
respect to a k-dependent number of poles.
