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

The correspondence principle is important in quantum theory on both thefundamental and practical levels: it is needed to connect theory to experiment,and for calculations in the technologically important domain lying between theatomic and classical regimes. Moreover, a correspondence-principle part of theS-matrix is normally separated out in quantum electrodynamics in order toobtain a remainder that can be treated perturbatively. But this separation, asusually performed, causes an apparent breakdown of the correspondence principleand the associated pole-factorization property. This breakdown is spurious. Itis shown in this article, and a companion, in the context of a special case,how to extract a distinguished part of the S-matrix that meets thecorrespondence-principle and pole-factorization requirements. In a secondcompanion paper the terms of the remainder are shown to vanish in theappropriate macroscopic limits. Thus this work validates the correspondenceprinciple and pole factorization in quantum electrodynamics, in the specialcase treated here, and creates a needed computational technique.Comment: 55 pages, 3 Figures included as uuencoded, gzipped, tarred  encapsulated postscript files, uses math_macros.te

Quantum electrodynamics at large distances. I. Extracting the correspondence-principle part