Tidal and nonequilibrium Casimir effects in free fall

TL;DR

This paper investigates how Casimir energy behaves when a device is in free fall, revealing tidal effects that increase force and nonequilibrium dynamics causing energy to oscillate between plates, especially near black holes.

Contribution

It introduces a 1+1D model analyzing tidal and nonequilibrium effects on Casimir energy during free fall, highlighting dynamic energy redistribution and force modulation.

Findings

Tidal effects increase force on Casimir plates during free fall.

Casimir energy oscillates between plates in a nonequilibrium process.

Force modulation correlates with energy movement, resembling a classical liquid.

Abstract

In this work, we consider a Casimir apparatus that is put into free fall (e.g., falling into a black hole). Working in 1+1D, we find that two main effects occur: First, the Casimir energy density experiences a tidal effect where negative energy is pushed toward the plates and the resulting force experienced by the plates is increased. Second, the process of falling is inherently nonequilibrium and we treat it as such, demonstrating that the Casimir energy density moves back and forth between the plates after being "dropped,'' with the force modulating in synchrony. In this way, the Casimir energy behaves as a classical liquid might, putting (negative) pressure on the walls as it moves about in its container. In particular, we consider this in the context of a black hole and the multiple vacua that can be achieved outside of the apparatus.