English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We investigate, in the case of the $2\mathrm{p}-1\mathrm{s}$ transition inatomic Hydrogen, the behaviour of the spontaneously emitted electromagneticfield in spacetime. We focus on Glauber's wave function for the emitted photon,a quantity which we find is nonzero outside the lightcone at all times afterthe start of the emission. We identify the uncertainty on the position of thedecaying electron as a source of departure from causality in the naive sense ofthe term. We carry out a detailed study of the emitted electric field in themid- and far-field regions, through analytical and numerical computations aswell as asymptotic arguments.

Mid- and far-field deviations from causality in spontaneous light emission by atomic Hydrogen