# Bending of light by gravitational waves from localized sources

*Sergei M. Kopeikin, Gerhard Schäfer*, Jena

**Complete text (abstract only):**

The extremely high precision of current radio interferometric observations requires
a better theoretical treatment of secondary effects in the propagation of
electromagnetic signals in gravitational fields of astrophysical objects. Especially
important is the problem of propagation of light rays in the field of gravitational
waves emitted from localized sources.

A consistent approach is presented in which the propagation equations of light
rays are integrated in linear approximation in the Newtonian gravitational constant
and in the static monopole, spin, and time-dependent quadrupole moment
approximation of the gravitational field. We demonstrate for the first time that the
equations of light propagation in the retarded gravitational field of an arbitrary
localized source emitting gravitational waves can be exactly integrated in closed
form. The contributions as well from the wave zone of the gravitational field as
from the intermediate and near zones are taken into account. We reproduce the
known results of integration of equations of light rays, both in a stationary
gravitational field and in the field of plane gravitational waves. Analytic
expressions for light deflection and integrated time delay are obtained for various
relative locations of the source of gravitational waves, the source of light rays (star,
quasar), and the observer. The relevance of the developed formalism for present
and future radio interferometric observations is discussed.

*A comprehensive article will be submitted to Phys. Rev. D: ťAstrometric and
Timing Effects of Gravitational Waves from Localized SourcesŤ by S. M. Kopeikin,
G. Schäfer, C. R. Gwinn and T. M. Eubanks.*

**Bibliographical details:**

Sergei M. Kopeikin, Gerhard Schäfer:
Bending of light by gravitational waves from localized sources.
In: Peter Brosche, Wolfgang R. Dick, Oliver Schwarz, Roland Wielen (Eds.):
The Message of the Angles -
Astrometry from 1798 to 1998. Proceedings of the
International Spring Meeting of the Astronomische Gesellschaft, Gotha, May
11-15, 1998. (Acta Historica Astronomiae ; 3).
Thun ; Frankfurt am Main : Deutsch, 1998, p. 240.

Html-Version: Wolfgang R. Dick.
Created: 21 Jan 1999