Modified light cone condition via vacuum polarization in a time dependent field

TL;DR

This paper analytically derives a modified light cone condition for probe light passing through a vacuum influenced by intense, time-dependent laser fields, revealing differences from conventional models and implications for vacuum birefringence measurements.

Contribution

It provides an analytical derivation of the vacuum polarization effect in a time-dependent field without assuming a constant pump field, advancing understanding of vacuum birefringence.

Findings

Derived modified light cone condition for time-dependent fields

Identified differences from conventional light cone models

Discussed implications for vacuum birefringence experiments

Abstract

The appearance of unconventional vacuum properties in intense fields has long been an active field of research. In this paper the vacuum polarization effect is investigated via a pump probe scheme of a probe light propagating in the vacuum excited by two counter-propagating laser beams. The modified light cone condition of the probe light is derived analytically for the situation that it passes through the electric/magnetic antinode plane of the pump field. The derivation does not follow the commonly adopted assumption of treating the pump field as a constant field. Differences from the conventional light cone conditions are identified. The implications of the result are discussed with a consideration of the vacuum birefringence measurement.