Parametric amplification of electromagnetic plasma waves in resonance with a dispersive background gravitational wave

TL;DR

This paper demonstrates that electromagnetic plasma waves can be parametrically amplified when propagating in resonance with a background gravitational wave in a dispersive medium, modeled by a Whitaker-Hill equation.

Contribution

It introduces a novel mechanism for amplifying plasma waves via resonance with gravitational waves, highlighting the importance of dispersive characteristics and response frequency matching.

Findings

Electromagnetic plasma waves can undergo exponential amplification at resonance.

The dynamics are governed by a Whitaker-Hill equation indicating parametric instability.

Amplification depends on specific dispersive and frequency matching conditions.

Abstract

It is shown that a sub-luminal electromagnetic plasma wave, propagating in phase with a background sub-luminal gravitational wave in a dispersive medium, can undergo parametric amplification. For this phenomena to occur, the dispersive characteristics of the two waves must properly match. The response frequencies of the two waves (medium dependent) must lie within a definite and restrictive range. The combined dynamics is represented by a Whitaker-Hill equation, the quintessential model for parametric instabilities. The exponential growth of the electromagnetic wave is displayed at the resonance; the plasma wave grows at the expense of the background gravitational wave. Different physical scenarios, where the phenomenon can be possible, are discussed.