Scattering of scalar, electromagnetic and gravitational waves from binary systems

TL;DR

This paper investigates how electromagnetic and gravitational waves scatter off binary systems, providing new calculations of scattering cross-sections and resonances, which could be relevant for future gravitational-wave observations.

Contribution

It offers the first detailed analysis of wave scattering by binary systems, including cross-sections and resonance effects, relevant for upcoming gravitational-wave detectors.

Findings

Scattering amplitude ratio can reach 10^{-5} for known pulsars.

Interaction cross-section is negligible for current binary distributions.

Resonance effects are characterized for the first time.

Abstract

The direct detection of gravitational waves crowns decades of efforts in the modelling of sources and of increasing detectors' sensitivity. With future third-generation Earth-based detectors or space-based observatories, gravitational-wave astronomy will be at its full bloom. Previously brushed-aside questions on environmental or other systematic effects in the generation and propagation of gravitational waves are now begging for a systematic treatment. Here, we study how electromagnetic and gravitational radiation is scattered by a binary system. Scattering cross-sections, resonances and the effect of an impinging wave on a gravitational-bound binary are worked out for the first time. The ratio between the scattered-wave amplitude and the incident wave can be of order $10^{-5}$ for known pulsars, bringing this into the realm of future gravitational-wave observatories. For currently realistic distribution of compact-object binaries, the interaction cross-section is too small to be of relevance.