Graduate Student Seminar with Liam Brodie on Neutron Stars

Neutron stars are places in our universe where extremely dense matter is found. I will discuss how we learn about neutron stars through observation and theory. Details of my contribution to the theory portion are found below.

The equation of state (EoS) for dense, beta-equilibrated nuclear matter is a fundamental ingredient for simulations of binary neutron star mergers, calculation of cooling curves, and other transport properties. We construct a new EoS using a relativistic mean-field theory (RMF). Typically, the couplings in an RMF are fit to isospin-symmetric nuclear matter data, but the matter in neutron stars is much closer in composition to pure neutron matter. In this work, along with reproducing isospin-symmetric nuclear matter data, we also fit our RMF to pure neutron matter calculations from chiral effective field theory. These calculations are needed because it is not possible to perform experiments on pure neutron matter on Earth. Our EoS agrees with current mass and radius measurements from NICER and LIGO.