Vortex lattice in rotating neutron spin-triplet superfluid

In the Ginzburg-Landau limit, a possible texture without singular cores in a rotating neutron spin-triplet superfluid is studied. It is constructed the lattice of non-singular vortices with a vorticity diffusely distributed over the entire unit cell. The upper limit of the free energy associated with this structure is estimated, and the result shows that non-singular vortices are more preferable in the core of rotating neutron stars than ordinary linear singular vortices. The order parameter of the studied neutron system belongs to the unitary class. This implies that the superfluid under consideration does not have spin polarization and the core-less $^{3}$P$_{2}$ vortices do not have magnetization, which makes electron scattering by vortices ineffective. For the same reason, pinning with flux tubes is also suppressed. This can affect the hydrodynamics of superfluid neutron stars.