Electronic contribution to the oscillations of a gravitational antenna

TL;DR

This paper investigates the microscopic electron-graviton interaction in metallic gravitational antennas and finds it negligible, confirming that direct coupling with the bar's normal modes dominates the interaction.

Contribution

It derives the microscopic Hamiltonian for the wave-antenna system and quantifies the electron-graviton interaction's negligible effect on damping.

Findings

Electron-graviton interaction is negligible compared to viscosity damping.

Direct coupling with normal modes is the primary interaction mechanism.

Microscopic analysis confirms previous assumptions about damping mechanisms.

Abstract

We carefully analyse the contribution to the oscillations of a metallic gravitational antenna due to the interaction between the electrons of the bar and the incoming gravitational wave. To this end, we first derive the total microscopic Hamiltonian of the wave-antenna system and then compute the contribution to the attenuation factor due to the electron-graviton interaction. As compared to the ordinary damping factor, which is due to the electron viscosity, this term turns out to be totally negligible. This result confirms that the only relevant mechanism for the interaction of a gravitational wave with a metallic antenna is its direct coupling with the bar normal modes.