How beaming of gravitational waves compares to the beaming of electromagnetic waves: impacts to gravitational wave detection

TL;DR

This paper investigates the beaming patterns of gravitational waves from gamma ray bursts, comparing them to electromagnetic radiation, and explores how speed influences the angular distribution of emitted power, impacting gravitational wave detection.

Contribution

It provides a detailed analysis of gravitational wave beaming from GRBs as a function of speed, highlighting differences from electromagnetic beaming and offering insights into detection strategies.

Findings

Gravitational wave beaming is isotropic at high speeds and polar at low speeds.

The angular distribution of GW power is opposite to that of EM radiation from GRBs.

Maximum power emission angles depend on the speed of the source.

Abstract

We focus on understanding the beaming of gravitational radiation from gamma ray bursts (GRBs) by approximating GRBs as linearly accelerated point masses. For accelerated point masses, it is known that gravitational radiation is beamed isotropicly at high speeds, and beamed along the polar axis at low speeds. Aside from this knowledge, there has been very little work done on beaming of gravitational radiation from GRBs, and the impact beaming could have on gravitational wave (GW) detection. We determine the following: (1) the observation angle at which the most power is emitted as a function of speed, (2) the maximum ratio of power radiated away as a function of speed, and (3) the angular distribution of power ratios at relativistic and non-relativistic speeds. Additionally the dependence of the beaming of GW radiation on speed is essentially the opposite of the beaming of electromagnetic (EM) radiation from GRBs. So we investigate why this is the case by calculating the angular EM radiation distribution from a linear electric quadrupole, and compare this distribution to the angular gravitational radiation distribution from a GRB.