Current Theoretical Insights into Magnetars

The last four years have witnessed a substantial number of new observational manifestations for magnetars, encompassing fast radio burst (FRB) associations, detection of giant flares in extragalactic magnetars, high cadence observations of glitch epochs, and new X-ray polarization information from IXPE. This talk summarizes some recent interpretative and theoretical advances that address both persistent surface emission elements and magnetospheric transients. These include how spectral evolution due to Doppler beaming in magnetar giant flares can be used to constrain the star’s rotation period. The strong, ephemeral wind model of rapid spin-down epochs associated with glitch activity will be explored. Pair creation conditions in twisted magnetospheres and their potential impact on FRB generation models are summarized. Magnetar surface emission is addressed in the context of atmosphere models that provide a benchmark for assessing the existence of condensed surfaces that have been suggested by some IXPE polarization data. Finally, the talk discusses the possible acoustic origin for quasi-periodic spectral oscillations seen in two short bursts from a Galactic magnetar.