Speaker
Description
Matter with extreme baryon density is believed to occur in the core of a neutron star, allowing for various novel phases, from conventional nucleon superfluid phase to exotic high baryon density QCD phases. Here, we point out a unique phenomenon associated with phase transitions to a superfluid phase, which may be the nucleon superfluid phase, or a phase like CFL phase, allowing for superfluid vortices. A random network of vortices forms via the Kibble-Zurek mechanism in any superfluid phase transition. The angular momentum carried by the random superfluid vortex network has to be balanced by an equal and opposite angular momentum in the normal fluid due to the conservation of angular momentum, thereby imparting an arbitrarily oriented angular momentum component to the outer shell in the case of a neutron star. This will induce a wobbling
of the neutron star and affect its spin, which can be detected for pulsars with high-precision measurements of the pulse timings and the pulse profile changes.
