Dipole gravity waves from unbound quadrupoles

TL;DR

This paper explores the generation and detection of dipole gravitational waves from unbound quadrupoles, proposing laboratory experiments and estimating signals from astrophysical events.

Contribution

It introduces the concept of dipole gravitational waves from unbound quadrupoles and calculates their angular distributions, proposing experimental detection methods.

Findings

Dipole gravitational signals can be generated by nonrelativistic and relativistic quadrupoles.

Laboratory setups like modified flywheels and LHC proton bunches can produce detectable dipole signals.

Astrophysical events involving unbound quadrupoles can generate measurable gravitational wave signals.

Abstract

Dipole gravitational disturbances from gravitationally unbound mass quadrupoles propagate to the radiation zone with signal strength at least of quadrupole order if the quadrupoles are nonrelativistic, and of dipole order if relativistic. Angular distributions of parallel-polarized and transverse-polarized dipole power in the radiation zone are calculated for simple unbound quadrupoles, like a linear-oscillator/stress-wave pair and a particle storage ring. Laboratory tests of general relativity through measurements of dipole gravity waves in the source region are proposed. A NASA G2 flywheel module with a modified rotor can produce a post-Newtonian dc bias signal at a gradiometer up to 1 mE. At peak luminosity, the repulsive dipole impulses of proton bunches at the LHC can produce an rms velocity of a high-Q detector surface up to 4 micron/s. Far outside the source region, Newtonian lunar dipole gravity waves can produce a 1-cm displacement signal at LISA. Dipole signal strengths of astrophysical events involving unbound quadrupoles, like near collisions and neutron star kicks in core-collapse supernovae, are estimated.