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Title: Scalar field dynamics in Friedmann-Robertson-Walker spacetimes

Journal Article · · Physical Review, D
 [1]; ;  [2];  [3]; ;  [4]
  1. Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
  2. Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
  3. Laboratoire de Physique Theorique et Hautes Energies Universite Pierre et Marie Curie (Paris VI), Tour 16, 1er. etage, 4, Place Jussieu 75252 Paris, Cedex 05 (France)
  4. Department of Physics, University of California, Santa Barbara, California 93106 (United States)

We study the nonlinear dynamics of quantum fields in matter- and radiation-dominated universes, using the nonequilibrium field theory approach combined with the nonperturbative Hartree and the large N approximations. We examine the phenomenon of explosive particle production due to spinodal instabilities and parametric amplification in expanding universes with and without symmetry breaking. For a variety of initial conditions, we compute the evolution of the inflaton, its quantum fluctuations, and the equation of state. We find explosive growth of quantum fluctuations, although particle production is somewhat sensitive to the expansion of the universe. In the large N limit for symmetry-breaking scenarios, we determine generic late time solutions for any flat Friedmann-Robertson-Walker (FRW) cosmology. We also present a complete and numerically implementable renormalization scheme for the equation of motion and the energy momentum tensor in flat FRW cosmologies. In this scheme the renormalization constants are independent of time and of the initial conditions. {copyright} {ital 1997} {ital The American Physical Society}

Research Organization:
Carnegie-Mellon University
DOE Contract Number:
FG02-91ER40682
OSTI ID:
538648
Journal Information:
Physical Review, D, Vol. 56, Issue 4; Other Information: PBD: Aug 1997
Country of Publication:
United States
Language:
English