Unexciting classical backgrounds

  title={Unexciting classical backgrounds},
  author={Tanmay Vachaspati},
  journal={Physical Review D},
  • T. Vachaspati
  • Published 6 January 2022
  • Mathematics
  • Physical Review D
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… 

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  • Rev. D 84, 125028
  • 2011


  • Rev. D 81, 085020
  • 2010


  • Phys. B 157, 285 (1979), [Erratum: Nucl.Phys.B 172, 544
  • 1980