Perturbation of the Kerr Metric
  A new Kerr-like metric with quadrupole moment is obtained by means of perturbing the Kerr spacetime. By comparison with the exterior Hartle-Thorne metric, it is showed that it could be matched to an interior solution. This metric may represent the spacetime of an astrophysical object. 
Francisco Frutos-Alfaro
gr-qc astro-ph.CO