Pulsar magnetospheres admit non-stationary vacuum gaps that are characterized by non-vanishing EB. These gaps play an important role in plasma production and electromagnetic wave emission and, as I will discuss, are very efficient axion factories. The density of axions produced in a vacuum gap can be several orders of magnitude greater than the ambient dark matter density.  In the strong pulsar magnetic field, a fraction of these axions may convert to photons, giving rise to broadband radio signals. We show that dedicated observations of nearby pulsars with radio telescopes (FAST) and interferometers (SKA) can probe axion-photon couplings that are a few orders of magnitude lower than current astrophysical bounds.


Talk Number PIRSA:21110016
Speaker Profile Anirudh Prabhu
Collection Particle Physics