Assess the astrophysical meaning and uniqueness of rotating-vector-model geometries

Determine whether geometric parameters inferred from rotating-vector-model fits to polarization-angle variations are astrophysically meaningful and whether sources with energy-dependent polarization-angle behavior are representative or outliers.

Background

Rotating-vector models provide a simple description of polarization-angle variation under a dipolar-field assumption, but alternative configurations and propagation effects have not been incorporated sufficiently. The review specifically highlights the contrasting energy-dependent polarization-angle behavior of Cen X-3 and leaves unresolved whether such behavior is exceptional and whether the geometric parameters obtained from simple fits have physical significance.

References

It therefore remains to be seen whether sources such Cen~X-3 are outliers or not, and, consequently, whether the geometric parameters obtained from RVM models are astrophysically meaningful or not.

— 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 3.2, “Polarization in pulse profiles”

It is not clear, however, if this reflects the physical reality, as non-symmetric pulse profiles can be equally achieved by more complex emission profiles or emitting geometries.

— 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 5.3, “Three examples: How do derived geometric parameters depend on the model?”