Lectures on Neutron Star Structure I

This is a lecture series by Prof. Mark Alford (Washington University in St. Louis) on the structure of neutron stars.

Oct. 7 (Tues), 15:30-17:00
Lecture I: Quark matter: the high-density frontier
The densest predicted state of matter is color-superconducting quark matter, which has some affinities to electrical superconductors, but a much richer phase structure because quarks come in many varieties. This form of matter may well exist in the core of compact stars, and the search for signatures of its presence is currently proceeding. I will review the nature of color-superconducting quark matter, and discuss some ideas for finding it in nature.

Oct. 14 (Tues), 15:30-17:00
Lecture II: Solid quark matter
I will review three ways in which quark matter can occur in a solid phase, where translational invariance is broken by some sort of crystalline structure. These include a color superconductor of the Fulde-Ferrell-Larkin-Ovchinnikov type, mixed phases that can arise at a nuclear/quark matter interface, and the strangelet crystal crust of a strange star.

Oct. 21 (Tues), 15:30-17:00
Lecture III: Dissipation in neutron star mergers
In a neutron star merger, nuclear matter experiences dramatic changes in temperature and density that happen in milliseconds. Mergers therefore probe dynamical properties that may help us uncover the phase structure of ultra-dense matter. I will describe some of the relevant material properties, focusing on flavor equilibration and its consequences such as bulk viscosity and damping of oscillations.

Oct. 28 (Tues), 15:30-17:00
Lecture IV: Neutrinos in dense matter: beyond modified Urca
Neutrino absorption and emission (the "Urca process") is an essential aspect of the formation and cooling of neutron stars and of the dynamics of neutron star mergers. In this talk I will describe the traditional way of calculating Urca rates, explain its shortfalls, and propose an alternative approach, the nucleon width approximation.