Quantised vortices and mutual friction in relativistic superfluids

Abstract

We consider the detailed dynamics of an array of quantised superfluid vortices in the framework of general relativity, as required for quantitative modelling of realistic neutron star cores. Our model builds on the variational approach to relativistic (multi-) fluid dynamics, where the vorticity plays a central role. The description provides a natural extension of, and a better insight into, existing Newtonian models. In particular, we account for the mutual friction associated with scattering of a second ‘normal’ component in the mixture off of the superfluid vortices. This is an important step which facilitates the connection with the involved microphysics.