SUPERFLUID DENSITIES IN NEUTRON-STAR MATTER

The superfluid densities in a mixture of neutron and proton superfluid s are discussed within Fermi-liquid theory. There are the usual diagon al densities rho(nn) and rho(pp) but also off-diagonal densities rho(n p) and rho(pn) which represent coupling between the two species. We ex press these quantities solely in terms of the Fermi momenta and the La ndau parameter f(l)(pn) in a way that explicitly satisfies the Galilea n invariance constraints rho(pp)+rho(pn)=m(p)n(p) and rho(nn)+rho(pn)= m(n)n(n)(.) The results are of astrophysical interest, e.g., in a disc ussion of the damping of gravitational instability in rapidly rotating neutron stars or of post-glitch relaxation of pulsars.