Analyzing Effects of the Nuclear Equation of State on Properties of Neutron Stars

Document Type


Degree Name

Master of Science (MS)


Physics and Astronomy

Date of Award

Fall 2020


Neutron stars are very dense objects composed of nuclear matter (neutrons, protons, mesons, and electrons), and are among the most mysterious objects in the universe. Neutron stars have a lot more neutrons than protons. The nuclear equation of state (EOS) is a relationship linking the pressure, neutron/proton ratio/asymmetry and density of nuclear matter inside neutron stars. The EOS thus has a symmetry energy term describing the energy associated with the neutron/proton ratio/asymmetry in neutron stars. It is a necessary input for solving numerically the Tolman-Oppenheimer-Volkov (TOV) equation governing the structure of neutron stars. To describe the EOS, one must know the L, Ksym, and Jsym, which are the slope, curvature, and skewness parameters of the symmetry energy. These parameters affect the mass, radius, and tidal deformability of neutron stars, which in turn tells us more about the underlying EOS of nuclear matter. This project focuses on investigating effects of various parameters of EOSs (L, Ksym, Jsym, etc.) that impact the properties of neutron stars (mass, radius, and tidal deformability). By comparing calculations and using these EOSs with data from recent observations of x-ray satellites and/or gravitational wave detectors, we have found that the crust-core transition density is dependent upon the L, Ksym, and Jsym as well as the Ksym- L correlations. Furthermore, we have determined that Ksym impacted the crust-core transition the most and have shown that Jsym barely impacts the parameters of neutron stars.


Bao-An Li

Subject Categories

Astrophysics and Astronomy | Physical Sciences and Mathematics