Persistence of complex multipolar magnetic fields in isolated neutron stars

Ascertain whether complex multipolar magnetic field configurations can persist for long periods in isolated neutron stars, including recycled millisecond pulsars such as PSR J0437−4715, given the competing effects of diffusive processes and accretion-induced spin-up that may alter field structure.

Background

The inferred hotspot geometry for PSR J0437−4715 suggests a magnetic field more complex than a centered dipole, potentially involving an offset dipole or quadrupole components. Such complexity aligns with radio polarization and emission modeling that challenges simple dipole assumptions.

The long-term survival of multipolar fields in isolated neutron stars is not established, and field evolution during accretion-induced recycling could further modify configurations, motivating an explicit question about field longevity.