Quantum larmor radiation in a conformally flat universe

Rampei Kimura, Gen Nakamura, Kazuhiro Yamamoto

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We investigate the quantum effect on the Larmor radiation from a moving charge in an expanding universe based on the framework of the scalar quantum electrodynamics. A theoretical formula for the radiation energy is derived at the lowest order of the perturbation theory with respect to the coupling constant of the scalar quantum electrodynamics. We evaluate the radiation energy on the background universe so that the Minkowski spacetime transits to the Milne universe, in which the equation of motion for the mode function of the free complex scalar field can be exactly solved in an analytic way. Then, the result is compared with the WKB approach, in which the equation of motion of the mode function is constructed with the WKB approximation which is valid as long as the Compton wavelength is shorter than the Hubble horizon length. This demonstrates that the quantum effect on the Larmor radiation of the order e2 is determined by a nonlocal integration in time depending on the background expansion. We also compare our result with a recent work by Higuchi and Walker, which investigated the quantum correction to the Larmor radiation from a charged particle in a nonrelativistic motion in a homogeneous electric field.

Original languageEnglish
Article number045015
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Volume83
Issue number4
DOIs
Publication statusPublished - 2011 Feb 17
Externally publishedYes

Fingerprint

universe
radiation
quantum electrodynamics
scalars
equations of motion
Wentzel-Kramer-Brillouin method
transit
horizon
charged particles
perturbation theory
expansion
electric fields
energy
wavelengths

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)

Cite this

Quantum larmor radiation in a conformally flat universe. / Kimura, Rampei; Nakamura, Gen; Yamamoto, Kazuhiro.

In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 83, No. 4, 045015, 17.02.2011.

Research output: Contribution to journalArticle

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