Wednesday 10^th December 2008, 2:00 P.M.

Università "La Sapienza" Roma - Sala Direzione INFN (2° piano Dip. Fisica, Ed. Marconi - Vecchio Edificio)

Title: Vacuum and electrovacuum generalizations of Kerr spacetime

Abstract: I present a class of exact solutions of Einstein and Einstein-Maxwell equations which contains the Kerr spacetime as a special limiting case. The solutions are characterized by an infinite set of independent (relativistic) multipole moments for an arbitrary, stationary, axisymmetric distribution of mass and angular momentum. The solution is asymptotically flat and corresponds in the Newtonian limit to the gravitational potential of a general axisymmetric distribution of mass. Moreover, it is free of singularities outside a region which could, in principle, be covered by a still unknown interior solution. We conclude that the solution can be used to describe the exterior gravitational field of an arbitrarily rotating axisymmetric distribution of mass.