Nuclear pasta and the deep inner crust*

The crust of a neutron star is an exotic condensed matter system, rich in physics and accessible through a host of astrophysical observables. Measurements of individual neutron star cooling and pulsar glitches, of long timescale temperature, magnetic field and rotational evolution evolution by analysis of neutron star populations, and potential observations of oscillations of the solid crust and even crust shattering all probe the thermal, mechanical, and superfluid properties of the crust.

We discuss recent progress in understanding some of these properties and their observational impact, including insights from microscopic, quantum simulations of the soft condensed matter system predicted to lie at the crust-core boundary, known as nuclear pasta. We also discuss how the strategy of statistical inference using ensembles of equation of state

that has been so successful in constraining the core equation of state can be applied to crust modeling, and how that will allow us to bring the host of crust observables to bear on the multimessenger physics of neutron stars.