Domain walls in a FRW universe
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
We solve the equations of motion for a scalar field with domain wall boundary conditions in a Friedmann-Robertson-Walker (FRW) spacetime. We find (in agreement with Basu and Vilenkin) that no domain wall solutions exist in de Sitter spacetime for {ital H}{equivalent_to}{ital H}/{ital m}{ge}1/2, where {ital H} is the Hubble parameter and {ital m} is the scalar mass. In the general FRW case we develop a systematic perturbative expansion in {ital h} to arrive at an approximate solution to the field equations. We calculate the energy-momentum tensor of the domain wall configuration, and show that the energy density can become {ital negative} at the core of the defect for some values of the nonminimal coupling parameter {xi}. We develop a translationally invariant theory for fluctuations of the wall, obtain the effective Lagrangian for these fluctuations, and quantize them using the Bunch-Davies vacuum in the de Sitter case. Unlike previous analyses, we find that the fluctuations act as zero-mass (as opposed to tachyonic) modes. This allows us to calculate the distortion and the normal-normal correlators for the surface. The normal-normal correlator decreases logarithmically with the distance between points for large times and distances, indicating that the interface becomes rougher than in Minkowski spacetime.
- Research Organization:
- Carnegie-Mellon University
- DOE Contract Number:
- FG02-91ER40682
- OSTI ID:
- 130742
- Journal Information:
- Physical Review, D, Vol. 52, Issue 10; Other Information: PBD: 15 Nov 1995
- Country of Publication:
- United States
- Language:
- English
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