Despite the absence of viscous drag, the neutron superfluid permeating the
inner crust of a neutron star can still be strongly coupled to nuclei due to
non-dissipative entrainment effects. Neutron superfluidity and entrainment have
been systematically studied in all regions of the inner crust of a cold
non-accreting neutron star in the framework of the band theory of solids. It is
shown that in the intermediate layers of the inner crust a large fraction of
"free" neutrons are actually entrained by the crust. The results suggest that a
revision of the interpretation of many observable astrophysical phenomena might
be necessary.Comment: 4 pages, to appear in the proceedings of the ERPM conference, Zielona
Gora, Poland, April 201