  Pulsars are spinning extremely rapidly with periods as short as about $1.4$
milliseconds and delays of a few milliseconds per year at most, thus providing
the most accurate clocks in the Universe. Nevertheless, sudden spin ups have
been detected in some pulsars like the emblematic Vela pulsar. These abrupt
changes in the pulsar's rotation period have long been thought to be the
manifestation of a neutron superfluid permeating the inner crust of neutron
stars. However, the neutron superfluid has been recently found to be so
strongly coupled to the crust that it does not carry enough angular momentum to
explain the Vela data. We explore the extent to which pulsar-timing
observations can be reconciled with the standard glitch theory considering the
lack of knowledge of the dense-matter equation of state.
