On the Bel radiative gravitational fields

Radiative gravitational fields and asymptotically static or stationary initial data

We describe our present understanding of the relation between the behaviour near space-like infinity of asymptotically flat Cauchy data for Einstein’s vacuum field equations and the asymptotic behaviour of their time evolution at null infinity. It is shown that asymptotically flat, static vacuum solutions admit an analytic conformal representation in a neighbourhood of the critical sets at whic...

Gravitational fields on a noncommutative space

Noncommutative three-dimensional gravity can be described in terms of a noncommutative Chern-Simons theory. We extend this structure and also propose an action for gravitational fields on an even dimensional noncommutative space. The action is worked out in some detail for fields on a noncommutative CP and on S.

Can Schwarzschildean gravitational fields suppress gravitational waves?

Gravitational waves in the linear approximation propagate in the Schwarzschild spacetime similarly as electromagnetic waves. A fraction of the radiation scatters off the curvature of the geometry. The energy of the backscattered part of an initially outgoing pulse of the quadrupole gravitational radiation is estimated by compact formulas depending on the initial energy, the Schwarzschild radius...

Time-Independent Gravitational Fields

Radiative tail of realistic rotating gravitational collapse

An astrophysically realistic model of wave dynamics in black-hole spacetimes must involve a nonspherical background geometry with angular momentum. We consider the evolution of gravitational (and electromagnetic) perturbations in rotating Kerr spacetimes. We show that a rotating Kerr black hole becomes "bald" slower than the corresponding spherically symmetric Schwarzschild black hole. Moreover...