Superfluidity in Neutron Stars

Abstract

MATTER in the interior of a typical neutron star is a mixture of three degenerate interacting quantum liquids—neutrons, protons and electrons, the latter two having a density at most a few per cent that of the neutrons¹. The mixture, bounded on the inside by a superdense core of hadrons, muons and so on, and most likely by a solid mantle on the outside², is of density between 5 × 10¹³ and 10¹⁵ g cm⁻³. As was first pointed out by Migdal³, and more recently discussed by others^4–8, there are quite possibly superfluid states in this interior. Here we discuss certain general features of such states and the extent to which they influence the properties of the star.