Sudden appearance of a thick Dirichlet wall in a cavity

TL;DR

This paper studies the sudden emergence of a thick Dirichlet boundary in a 1D cavity and analyzes how it affects the vacuum energy density and particle creation, revealing dependence on the wall's size characteristics.

Contribution

It introduces a model for the instantaneous appearance of a thick Dirichlet wall and derives the resulting energy and particle densities, highlighting dependence on the wall's size nature.

Findings

Energy density depends on whether the wall's length is rational or irrational.

Particle number density is calculated for the sudden boundary appearance.

The results show significant effects on vacuum properties due to boundary changes.

Abstract

We investigate the vacuum properties of a massless scalar field theory in constrained spatial geometry, namely, the instantaneous appearance of a thick Dirichlet boundary inside a one-dimensional (1D) Dirichlet cavity and divides it into two parts. Our work presents the calculations for the energy density and particle number density created. The expression of the energy density is found to be dependent on the size nature of the appearing wall, more precisely, it depends on whether the length of the wall is rational or irrational.