Universal Relations for the Increase in the Mass and Radius of a Rotating Neutron Star

Understand

Rotation causes an increase in a neutron star's mass and equatorial radius.

• The mass and radius depend sensitively on the unknown equation of state (EOS) of cold, dense matter.
• However, the increases in mass and radius due to rotation are almost independent of the EOS.
• The EOS independence leads to the idea of neutron star universality.