Three myths about time reversal in quantum theory

TL;DR

This paper defends the standard quantum mechanical notion of time reversal, arguing it is appropriate and justified by fundamental considerations about time in quantum theory.

Contribution

It clarifies misconceptions about time reversal in quantum theory and defends the standard definition as consistent with the nature of time.

Findings

The standard time reversal transformation is justified by quantum formalism.

Misconceptions about the non-appropriateness of time reversal are addressed.

The paper clarifies the conceptual foundations of time symmetry in quantum mechanics.

Abstract

Many have suggested that the transformation standardly referred to as 'time reversal' in quantum theory is not deserving of the name. I argue on the contrary that the standard definition is perfectly appropriate, and is indeed forced by basic considerations about the nature of time in the quantum formalism.