Constraints on Gravitational Dipole Radiation from Pulsars

TL;DR

This paper investigates how pulsar observations constrain theories of gravity involving long-range vector fields that could produce gravitational dipole radiation, finding that current data strongly limits such modifications.

Contribution

It provides the first comprehensive analysis of pulsar data to set stringent bounds on gravitational dipole emission predicted by alternative gravity theories.

Findings

Pulsar timing data impose tighter constraints than lunar laser ranging.

Gravitational dipole radiation is highly suppressed by observational limits.

Results significantly restrict modifications to general relativity involving vector fields.

Abstract

Recent suggestions for a modification of general relativity to provide an alternative approach to gravity in connection with the dark energy (matter) problem imply a long range vector component of the gravitational field. This could lead to emission of gravitational dipole emission from objects such as pulsars. Stringent observational limits on period changes of binary and millisecond pulsars and their consistency with general relativity impose severe limits on couplings of such forces. These bounds are tighter than those implied by lunar laser ranging experiments.