Time delays and advances in classical and quantum systems

TL;DR

This paper reviews and analyzes positive and negative time delays in classical and quantum systems, covering classical mechanics, quantum tunneling, scattering, quantum field theory, and experimental implications.

Contribution

It provides a comprehensive overview of time delays and advances across classical and quantum physics, including new interpretations and potential experimental measurements.

Findings

Quantum tunneling durations are quantified.

An interpretation of the Hartman paradox is proposed.

Possible experimental measurements of time delays are discussed.

Abstract

The paper reviews positive and negative time delays in various processes of classical and quantum physics. In the beginning, we demonstrate how a time-shifted response of a system to an external perturbation appears in classical mechanics and classical electrodynamics. Then we quantify durations of various quantum mechanical processes. The duration of the quantum tunneling is studied. An interpretation of the Hartman paradox is suggested. Time delays and advances appearing in the three-dimensional scattering problem on a central potential are considered. Then we discuss delays and advances appearing in quantum field theory and after that we focus on the issue of time delays and advancements in quantum kinetics. We discuss problems of the application of generalized kinetic equations in simulations of the system relaxation towards equilibrium and analyze the kinetic entropy flow. Possible measurements of time delays and advancements in experiments similar to the recent OPERA neutrino experiment are also discussed.