Magnetic braking of rotating contracting protostellar cores helps to solve the angular
momentum problem in low-mass star formation
(Mouschovias). It operates up to gas densitites
when ambipolar diffusion starts to redistribute the magnetic flux in the core. If this paradigm
is true, the theoretical prediction is that the ambipolar diffusion timescale is shorter for lower-metallicity molecular gas (owing to the lower fractional degree of ionisation) and that the collapse of protostellar cores in metal-poor
conditions (such as LMC/SMC) would result in higher angular momentum systems, i.e.
wider binaries and /or faster rotating stars.
This prediction can be tested observationally.