Approximate Universal Relations for Neutron Stars and Quark Stars

Understand

Neutron stars and quark stars are ideal laboratories to study fundamental physics at supra nuclear densities and strong gravitational fields.

• Astrophysical observables, however, depend strongly on the star's internal structure, which is currently unknown due to uncertainties in the equation of state.
• Universal relations, however, exist among certain stellar observables that do not depend sensitively on the star's internal structure.
• One such set of relations is between the star's moment of inertia ($I$), its tidal Love number (Love) and its quadrupole moment ($Q$), the so-called I-Love-Q relations.