Unexciting classical backgrounds

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Quantum fields in time-dependent backgrounds generally lead to particle production. Here we consider "unexciting"backgrounds for which the net particle production vanishes. We start by considering the simple harmonic oscillator and explicitly construct all unexciting time-dependent frequencies. This allows us to construct homogeneous backgrounds in field theory for which there is no particle production in any given mode, though we are able to show that there are no homogeneous backgrounds for which the particle production vanishes in every mode. We then construct general inhomogeneous unexciting field theory backgrounds. The set of all unexciting field theory backgrounds will be further restricted by the choice of physical interactions and this leads to an interesting open problem.

Original languageEnglish (US)
Article number056008
JournalPhysical Review D
Issue number5
StatePublished - Mar 1 2022

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'Unexciting classical backgrounds'. Together they form a unique fingerprint.

Cite this