
Figure 5: Top: Fitting curves (solid curve) and numerical results (points) of the universal I-Love
(left) and Q-Love (right) relations for various equations of state, normalized as
,
and
,
is the neutron-star mass,
is
the tidal Love number,
is the rotation-induced quadrupole moment, and
is the magnitude
of the neutron-star spin angular momentum. The neutron-star central density is the parameter varied
along each curve, or equivalently the neutron-star compactness. The top axis shows the neutron star
mass for the APR equation of state, with the vertical dashed line showing
. Bottom:
Relative fractional errors between the fitting curve and the numerical results. Observe that these
relations are essentially independent of the equation of state, with loss of universality at the 1% level.
Image reproduced by permission from [452], copyright by APS.


![Q¯ = − Q(rot)∕[M 3NS(S∕M N2S )2]](article1242x.gif)




