Fast-forward scheme reexamined: Choice of time and quantization

TL;DR

This paper reexamines the fast-forward scheme for quantum state evolution acceleration, concluding that it does not achieve its intended purpose due to covariance issues under time reparametrization.

Contribution

It provides a theoretical analysis showing the limitations of the fast-forward scheme based on Dirac's formalism and canonical quantization.

Findings

Fast-forward scheme does not accelerate quantum evolution as intended.

Covariance under time reparametrization prevents scheme's effectiveness.

Theoretical reexamination challenges previous assumptions about scheme's utility.

Abstract

The fast-forward scheme for accelerating time evolution of quantum states through change of time is reexamined. Dirac's homogeneous formalism for classical dynamics and canonical quantization warrant that the Schr\"odinger equation is covariant under reparametrization of time. From this, it is concluded that the scheme does not attain its objective.