Princeton University Donald R. Hamilton Colloquium Series

Abstract: Radio pulses from rotating neutron stars provide us with spectacularly accurate measurements of their spin frequencies. Surprisingly, young and middle-aged pulsars frequently exhibit irregular evolution of their spin frequencies, with long periods of gradual decrease punctuated by periods with rapid increases (the "glitches").  On top of that, many of them show evidence of
time-variable torques  (the "timing noise") that are correlated with the changes in pulsar magnetosphere, but are difficult to explain using the known magnetospheric physics.

Both glitches and timing noise are unsolved problems in neutron-star astrophysics, with the former likely related to a collective pinning and unpinning of quantum vorticity and the latter likely related to magnetic Hall waves in the star's crust. I will argue that

1. A superconducting phase transition in the core naturally leads to launching of Giant Hall Waves from the crust-core interface towards the magnetosphere.
2. The pinning and unpinning of vortices in the crust is very sensitive to the lattice structure and displays a strong hysteresis.
3. The gradual drift of the vortices leads to strong concentration of sperfluid flows in narrow channels - "the rivers".

I will speculate how these 3 ingredients might contribute to the theory of pulsar glitches and timing noise.