The endpoint formalism for the calculation of electromagnetic radiation and its applications in astroparticle physics
Abstract
We present the "endpoint" formalism for the calculation of electromagnetic radiation and illustrate its applications in astroparticle physics. We use the formalism to explain why the coherent radiation from the Askaryan effect is not in general Cherenkov radiation, as the emission directly results from the timevariation of the net charge in the particle shower. Secondly, we illustrate how the formalism has been applied in the air shower radio emission code REAS3 to unify the microscopic and macroscopic views of radio emission from extensive air showers. Indeed, the formalism is completely universal and particularly wellsuited for implementation in Monte Carlo codes in the time and frequencydomains. It easily reproduces wellknown "classical mechanisms" such as synchrotron radiation, VavilovCherenkov radiation and transition radiation in the adequate limits, but has the advantage that it continues to work in realistic, complex situations, where the "classical mechanisms" tend to no longer apply and adhering to them can result in misleading interpretations.
 Publication:

International Cosmic Ray Conference
 Pub Date:
 2011
 DOI:
 10.7529/ICRC2011/V04/0653
 arXiv:
 arXiv:1112.2126
 Bibcode:
 2011ICRC....4..308H
 Keywords:

 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 4 pages, contribution to the 32nd ICRC, Beijing, China