3 papers
hep-ph2026
Axion Hair and Pulsar Electrodynamics: modelling, discharge dynamics, and particle-in-cell simulations
Samuel J. Witte, Andrea Caputo, Stefan Stelzl +3
In a companion paper, we demonstrated that static axion field gradients sourced by dense nuclear matter (\emph{axion hair}) can dominate the near-field electrodynamics of old rotat…
hep-ph2025
Constraints on light QCD and CP-violating axions from the death line of rotation-powered pulsars
Samuel J. Witte, Andrea Caputo, Stefan Stelzl +3
Dense nuclear matter can modify the effective potential of axions, displacing them from their vacuum minimum, and sourcing large external field gradients (``axion hair"). In the ca…
hep-ph2023
Pulsar Nulling and Vacuum Radio Emission from Axion Clouds
Andrea Caputo, Samuel J. Witte, Alexander A. Philippov +1
Non-relativistic axions can be efficiently produced in in the polar caps of pulsars, resulting in the formation of a dense cloud of gravitationally bound axions. Here, we investiga…