Can Schwarzschildean gravitational fields suppress gravitational waves?

TL;DR

This paper investigates how Schwarzschild gravitational fields influence the propagation and backscattering of gravitational waves, providing estimates for the energy of backscattered waves and showing that backscatter diminishes at short wavelengths.

Contribution

It offers a quantitative analysis of gravitational wave backscatter in Schwarzschild spacetime, including formulas for energy estimates based on initial conditions.

Findings

Backscatter energy depends on initial energy, Schwarzschild radius, and pulse characteristics.

Backscatter becomes negligible for short wavelength gravitational waves.

Provides compact formulas for estimating backscattered energy.

Abstract

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, and the location and width of the pulse. The backscatter becomes negligible in the short wavelength regime.