  The neutron superfluid permeating the inner crust of mature neutron stars is
expected to play a key role in various astrophysical phenomena like pulsar
glitches. Despite the absence of viscous drag, the neutron superfluid can still
be coupled to the solid crust due to non-dissipative entrainment effects.
Entrainment challenges the interpretation of pulsar glitches and suggests that
a revision of the interpretation of other observed neutron-star phenomena might
be necessary.
