Probing the interior of neutron stars with gravitational waves
  We show here how the internal structure of a neutron star can be inferred from its gravitational wave spectrum. Under the premise that the frequencies and damping rates of a few $w$-mode oscillations are found, we apply an inversion scheme to determine its mass, radius and density distribution. In addition, accurate equation of state of nuclear matter can also be determined. 
L.K. Tsui and P.T. Leung