Catastrophic particle production under periodic perturbation

Jun, 1995
33 pages
Published in:
  • Prog.Theor.Phys. 94 (1995) 873-898
e-Print:
Report number:
  • TU-484,
  • TU-95-484

Citations per year

199520022009201620230510152025
Abstract:
We develop a formalism to investigate the behavior of quantum field and quantum ground state when the field is coupled to perturbation that periodically oscillates. Working in the Schroedinger picture of quantum field theory, we confirm that the phenomenon of parametric resonance in the classical theory implies an instability of quantum vacuum, and correspondingly it gives rise to catastrophic particle production if the oscillation lasts indefinitely; the produced number of particles exponentially increases without bound as time proceeds. The density matrix describing the limiting stage of the quantum state is determined by a small set of parameters. Moreover, the energy spectrum and the intensity of produced particles are worked out in greatest detail in the limit of weak coupling or small amplitude perturbation. In the case of strong coupling or large amplitude perturbation the leading adiabatic formula is derived. Application to cosmological fate of weakly interacting spinless fields (WISF) such as the invisible axion, the Polonyi, and the modular fields is discussed. Although very little effect is expected on the invisible axion, the Polonyi type field has a chance that it catastrophically decays at an early epoch without much production of entropy, provided that an intrinsic coupling is large enough.
  • particle: production
  • production: particle
  • ground state: perturbation
  • Gauss model
  • oscillation
  • density matrix
  • unitarity
  • energy spectrum
  • expansion: weak coupling
  • weak coupling: expansion