We study the linearized equations describing the propagation of gravitational waves through dust. In the leading order of the WKB approximation, dust behaves as a nondispersive, nondissipative medium. Taking advantage of these features, we explore the possibility that a gravitational wave from a distant source gets trapped by the gravitational field of a long filament of galaxies of the kind seen in the large scale structure of the Universe. Such a waveguiding effect may lead to a huge magnification of the radiation flux from distant sources, thus lowering the sensitivity threshold required for a successful detection of gravitational waves by detectors such as VIRGO, LIGO, and LISA.

• Received 1 December 1997

DOI:https://doi.org/10.1103/PhysRevD.58.104009