Comment on "Casimir Force Acting on Magnetostatic Bodies Embedded in Media"

TL;DR

This paper critically examines a proposed electromagnetic energy-momentum tensor for Casimir force calculations, highlighting its limitations and the need for experimental validation before acceptance.

Contribution

It challenges the universality and applicability of the Raabe-Welsch tensor in Casimir force computations, emphasizing potential issues and the necessity for experimental evidence.

Findings

The Raabe-Welsch tensor cannot describe simple classical electrodynamics scenarios effectively.

Modified Casimir forces in the theory have problematic properties and lack clear definiteness.

The theory requires experimental validation before it can be considered reliable.

Abstract

In a recent paper [C. Raabe and D.-G. Welsch, Phys. Rev. A 71, 013814 (2005)] an electromagnetic energy-momentum tensor is suggested as an alternative to the Abraham-Minkowski tensor and is applied to calculations of Casimir forces in planar geometries. We argue that the universality of the suggested tensor is doubtful; application of the Raabe-Welsch theory to a simple example in classical electrodynamics shows that their proposed tensor is unable to describe the situation in a simple way. We also show that modified Casimir forces acting on the cavity medium as prescribed by these authors suffer from problems of definiteness and peculiar properties which call for experimental support before this theory can be regarded as acceptable.