Classical and quantum radiation from a moving charge in an expanding universe

Hidenori Nomura, Misao Sasaki, Kazuhiro Yamamoto

Research output: Contribution to journalReview articlepeer-review

15 Citations (Scopus)


We investigate photon emission from a moving particle in an expanding universe. This process is analogous to the radiation from an accelerated charge in the classical electromagnetic theory. Using the framework of quantum field theory in curved spacetime, we demonstrate that the Wentzel-Kramers-Brillouin (WKB) approximation leads to the Larmor formula for the rate of the radiation of energy from a moving charge in an expanding universe. Using exactly solvable models in a radiation-dominated universe and in a Milne universe, we examine the validity of the WKB formula. It is shown that the quantum effect suppresses the radiation energy in comparison with the WKB formula.

Original languageEnglish
Article number013
JournalJournal of Cosmology and Astroparticle Physics
Issue number11
Publication statusPublished - Nov 1 2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics


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