Superfluidity in neutron stars

Astrophysical evidence is reviewed for the existence of at least three distinct superfluids inside neutron stars from the observed relaxation of the rotation and spin-down rates of the pulsars Vela, Crab, and PSR0525 + 21, following sudden jumps or glitches in these quantities. Theoretical aspects of neutron and proton superfluids in neutron stars and core neutron communication, glitches and post-glitch relaxation, neutron star coupling, and vortex creep theory are discussed. The effects of the superfluid interior in the accreting neutron star X-ray sources are also considered.