Comment on "Poynting vector controversy in axion modified electrodynamics"

TL;DR

This paper clarifies that the choice of Poynting vector definition does not affect physical measurements in axion electrodynamics, correcting errors in a recent claim about detector sensitivity enhancement.

Contribution

It provides a detailed explanation of the ambiguity in Poynting vector definitions and identifies errors in a recent study claiming sensitivity improvements.

Findings

The Poynting vector choice does not influence physical observables.

Errors in the previous calculation were identified and corrected.

Physical results remain consistent regardless of Poynting vector definition.

Abstract

In a recent publication, Tobar, McAllister, and Goryachev claim that using an alternative definition of the Poynting vector can dramatically enhance the sensitivity of their proposed axion dark matter detector. While the choice of Poynting vector is indeed ambiguous, it cannot affect physical results, such as the reading on a voltmeter, as long as the same definition is used consistently. I explain this point in detail, and locate the specific errors in their calculation.