Quantization of scalar perturbations in brane-world inflation

Nov, 2004
14 pages
Published in:
  • Phys.Rev.D 71 (2005) 043519
e-Print:
Report number:
  • UTAP-505

Citations per year

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Abstract:
We consider a quantization of scalar perturbations about a de Sitter brane in a 5-dimensional anti-de Sitter (AdS) bulk spacetime. We first derive the second order action for a master variable Ω\Omega for 5-dimensional gravitational perturbations. For a vacuum brane, there is a continuum of normalizable Kaluza-Klein (KK) modes with m>3H/2m>3H/2. There is also a light radion mode with m=2Hm=\sqrt{2}H which satisfies the junction conditions for two branes, but is non-normalizable for a single brane model. We perform the quantization of these bulk perturbations and calculate the effective energy density of the projected Weyl tensor on the barne. If there is a test scalar field perturbation on the brane, the m2=2H2m^2 = 2H^2 mode together with the zero-mode and an infinite ladder of discrete tachyonic modes become normalizable in a single brane model. This infinite ladder of discrete modes as well as the continuum of KK modes with m>3H/2m>3H/2 introduce corrections to the scalar field perturbations at first-order in a slow-roll expansion. We derive the second order action for the Mukhanov-Sasaki variable coupled to the bulk perturbations which is needed to perform the quantization and determine the amplitude of scalar perturbations generated during inflation on the brane.
  • 04.50.+h
  • 98.80.Cq
  • inflation
  • membrane model
  • perturbation: scalar
  • perturbation: quantization
  • dimension: 5
  • space-time: anti-de Sitter
  • energy: density
  • radiation