Speaker
Description
Neutron star interiors are very interesting environments to probe the nuclear matter equation of state (EOS), especially at the limit of high density and temperature. In this talk, I will discuss two approaches to constraining the neutron star EOS. The first approach consists of constraining the EOS with observations of neutron star mass, radius, and tidal deformability. I will explain how data from the NICER telescope and the LIGO-VIRGO interferometers are used for this purpose, and how constraints from ab initio calculations - such as chiral effective field theory (cEFT) and perturbative QCD (pQCD) – are incorporated to perform EOS inference. I will also discuss how the recent implementation of cEFT calculations including uncertainties obtained with Gaussian processes updated our knowledge of the high-density EOS behavior and enabled the inference of EOS parameters. The second approach to investigating the EOS is related to neutron star cooling and how X-ray astrophysical observations can be used to infer the evolution of neutron star luminosity over time. This kind of data can constrain other EOS quantities, such as particle composition and nuclear pairing. In particular, I will discuss how the luminosity of fast cooling, transiently-accreting neutron stars can be used to investigate a possible first-order quark-hadron phase transition.