Identify the symmetry that could explain the Crab pulsar’s constant position angle

Identify any symmetry of the axion-conversion surface or the axion cloud that could account for the constant position angle of the Crab pulsar’s zebra-like emission feature.

Background

The Crab pulsar’s zebra feature has a constant position angle, whereas the axion-induced conversion mechanism presented in the paper does not explain this property within the stated model. The authors note that such an explanation would require an as-yet-unidentified symmetry associated with either the conversion surface or the axion cloud.

Determining whether such a symmetry exists is necessary for assessing whether the observed polarization behavior can be reconciled with axion-induced conversion rather than standard plasma emission.