Determine the allowable geometry of plasma-loaded accretion funnels

Determine whether magnetic-field lines loaded with accreted plasma can support accretion-funnel shapes more complex than semi-circular configurations.

Background

The review describes several possible footprints for accretion flows onto magnetized neutron stars, including filled circles, hollow funnels, crescents, and ring-like structures. Magnetohydrodynamic instabilities and distortions of the magnetic field may cause leakage and chaotic filling of the accretion channel, but the range of geometries that can remain dynamically supported is unresolved.

References

It is unclear, however, whether shapes that are even more complex than semi-circular can be supported by $B$-field lines which are loaded with the accreted plasma.

— Pulse profiles of accreting neutron stars - A review of analysis methods, observations, and theoretical models  (2608.20876 - Pottschmidt et al., 21 Aug 2026) in Section 2.2.1, “Flow to the magnetic poles”