The Physics of the Neutron Star Crust-Core Transition: Observable Consequences and Nuclear Symmetry Energy Constraints

The observable consequences of the internal (thermo) dynamical states associated with various stages of a neutron star's life can help shed light on the microphysics that underlies them. In this talk, I will examine a number of observables thought to probe in some way the dynamical and thermal properties of the crust and its coupling to the neutron star core, and their potential for setting constraints on the nuclear symmetry energy around nuclear saturation density. I will touch upon the following topics: (i) The cooling rate of the neutron star in Cassiopeia A, (ii) the upper limit of the observed periods of young X-ray pulsars, (iii) glitches from the Vela pulsar, (iv) the frequencies of quasi-periodic observations in X-ray tail of light curves from giant flares from soft gamma-ray repeaters, (v) the upper limit on the frequency to which millisecond pulsars can be spun-up due to accretion from a binary companion, and (vi) tentative observations of precursor electromagnetic flares a few seconds before short gamma-ray bursts.