Cherenkov radiation from the quantum vacuum

TL;DR

This paper explores the theoretical possibility of Cherenkov radiation emitted from the quantum vacuum under strong electromagnetic fields, with potential implications for astrophysical high-energy photon observations.

Contribution

It introduces a model for vacuum Cherenkov radiation induced by quantum fluctuations in intense electromagnetic fields, a novel concept in quantum field theory and astrophysics.

Findings

Vacuum Cherenkov radiation can occur in strong laser pulses and pulsar magnetic fields.

Regimes identified where vacuum Cherenkov radiation dominates other emission mechanisms.

Potential explanation for excess high-energy photon signals in astrophysical data.

Abstract

A charged particle moving through a medium emits Cherenkov radiation when its velocity exceeds the phase velocity of light in that medium. Under the influence of a strong electromagnetic field, quantum fluctuations can become polarized, imbuing the vacuum with an effective anisotropic refractive index and allowing the possibility of Cherenkov radiation from the quantum vacuum. We analyze the properties of this vacuum Cherenkov radiation in strong laser pulses and the magnetic field around a pulsar, finding regimes in which it is the dominant radiation mechanism. This radiation process may be relevant to the excess signals of high energy photons in astrophysical observations.