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Title: Linearized Israel matching conditions for cosmological perturbations in a moving brane background

Journal Article · · Physical Review. D, Particles Fields
 [1];  [2]
  1. Laboratoire de Physique Theorique, Universite Paris-Sud, 91405 Orsay (France)
  2. Departament de Fisica Fondamental, Universitat de Barcelona, 08028 Barcelona (Spain)

In the Randall-Sundrum cosmological models, a (3+1)-dimensional brane subject to a Z{sub 2} orbifold symmetry is embedded in a (4+1)-dimensional bulk spacetime empty except for a negative cosmological constant. The unperturbed braneworld cosmological solutions, subject to homogeneity and isotropy in the three transverse spatial dimensions, are most simply presented by means of a moving brane description. Owing to a generalization of Birkhoff's theorem, as long as there are no perturbations violating the three-dimensional spatial homogeneity and isotropy, the bulk spacetime remains stationary and trivial. For the spatially flat case, the bulk spacetime is described by one of three bulk solutions: a pure AdS{sup 5} solution, an AdS{sup 5}-Schwarzschild black hole solution, or an AdS{sup 5}-Schwarzschild naked singularity solution. The brane moves on the boundary of one of these simple bulk spacetimes, its trajectory determined by the evolution of the stress-energy localized on the brane. We derive here the form of the Israel matching conditions for the linearized cosmological perturbations in this moving brane picture. These Israel matching conditions must be satisfied in any gauge. However, they are not sufficient to determine how to describe in a specific gauge the reflection of the bulk gravitational waves off the brane boundary. In this paper we adopt a fully covariant Lorentz gauge condition in the bulk and find the supplementary gauge conditions that must be imposed on the boundary to ensure that the reflected waves do not violate the Lorentz gauge condition. Compared to the form obtained from Gaussian normal coordinates, the form of the Israel matching conditions obtained here is more complex. However, the propagation of the bulk gravitons is simpler because the coordinates used for the background exploit fully the symmetry of the bulk background solution.

OSTI ID:
20709062
Journal Information:
Physical Review. D, Particles Fields, Vol. 71, Issue 8; Other Information: DOI: 10.1103/PhysRevD.71.083511; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
Country of Publication:
United States
Language:
English