Establish whether millisecond-pulsar profile variations are accompanied by spin-down-rate changes

Determine whether the long-term pulse-profile variations observed in millisecond pulsars are accompanied by changes in the spin-down rate, as reported for canonical pulsars.

Background

The study searches for variations in the spin-down rate, represented by changes in ν˙\dot{\nu}, in millisecond pulsars exhibiting clear quasi-periodic profile variations. No statistically significant detections are obtained, largely because the expected variations are small and the observed profile-state transitions are shorter than the persistence times needed for current timing data to resolve them.

Simulations indicate that unresolved low-level ν˙\dot{\nu} variations could contribute to weak achromatic timing noise, but the data do not establish whether the profile changes and spin-down-rate variations share a common physical origin. Longer timing baselines and analyses that explicitly model profile-change epochs are identified as necessary to resolve this question.

References

Future observations with longer timing baselines, together with analysis methods that explicitly incorporate the observed profile-change epochs when fitting for changes in $\dot{\nu}$, will improve the sensitivity to such measurements. These developments will be essential for determining whether the profile variations observed in millisecond pulsars are accompanied by changes in spin-down rate, as is observed in canonical pulsars.

— Time-Correlated Profile Variability in the MeerKAT Pulsar Timing Array  (2609.09919 - Bhat et al., 9 Sep 2026) in Section 5, subsection “Profile changes and timing noise”; reiterated in the Conclusions