Radiation Damping in Einstein-Aether Theory

TL;DR

This paper investigates gravitational radiation damping in Einstein-aether theory, deriving waveforms and energy loss rates that include monopolar, dipolar, and quadrupolar contributions, and compares them to general relativity.

Contribution

It derives gravitational waveforms and damping rates in Einstein-aether theory, highlighting conditions where the results match general relativity.

Findings

Waveforms depend on quadrupole, monopole, and dipole moments.

A one-parameter family of theories matches GR damping rates.

Strong internal field effects are not included in current tests.

Abstract

This work concerns the loss of energy of a material system due to gravitational radiation in Einstein-aether theory-an alternative theory of gravity in which the metric couples to a dynamical, timelike, unit-norm vector field. Derived to lowest post-Newtonian order are waveforms for the metric and vector fields far from a nearly Newtonian system and the rate of energy radiated by the system. The expressions depend on the quadrupole moment of the source, as in standard general relativity, but also contain monopolar and dipolar terms. There exists a one-parameter family of Einstein-aether theories for which only the quadrupolar contribution is present, and for which the expression for the damping rate is identical to that of general relativity to the order worked to here. This family cannot yet be declared observationally viable, since effects due to the strong internal fields of bodies in the actual systems used to test the damping rate are not included.