Dynamical Casimir effect and the possibility of laser-like generation of gravitational radiation

TL;DR

This paper explores the potential for laboratory generation of gravitational waves using superconducting cavities, drawing an analogy with the dynamical Casimir effect and proposing experimental setups to detect and produce gravitational radiation.

Contribution

It introduces the concept of 'relative gravitational permeativity' to describe matter's response to gravitational fields and proposes an experimental design to generate and detect gravitational waves in the lab.

Findings

Superconducting cavities may have high quality factors for gravitational radiation.

A new parameter, 'relative gravitational permeativity', models matter's response to gravitational waves.

Experimental setup with a coupled-cavity system could test gravitational wave reflection and generation.

Abstract

In this paper, we address the question as to whether or not measurable sources for gravitational waves could possibly be made in the laboratory. Based on an analogy of the dynamical Casimir effect with the stimulated emission of radiation in the laser, our answer to this question is in the affirmative, provided that superconducting radio-frequency cavities in fact possess high quality factors for both electromagnetic and gravitational microwave radiation, as one would expect due to a quantum-mechanical gravitational Meissner-like effect. In order to characterize the response of matter to tensor gravitational fields, we introduce a prefactor to the source term of the gravitational wave equation, which we call the "relative gravitational permeativity" analogous to the "relative electric permittivity" and "relative magnetic permeability" that characterize the vector response of matter to applied fields in electromagnetism. This allows for a possibly large quantum mechanical enhancement of the response of a superconductor to an incident tensor gravitational wave field. Finally, we describe our experimental work with high-Q superconducting radio-frequency cavities, and propose a design for a coupled-cavity system with a flexible superconducting membrane in its middle as its amplifying element. This will then allow us to test for a Meissner-like expulsion, and therefore reflection, of incident tensor gravitational wave fields, and, above a certain threshold, to generate coherent gravitational radiation via the dynamical Casimir effect.