Primordial spikes from wrapped brane inflation
- Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 3H8 (Canada)
- Research Center for the Early Universe, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
Cosmic inflation driven by branes wrapping the extra dimensions involves Kaluza-Klein (KK) degrees of freedom in addition to the zero-mode position of the brane which plays the role of the inflaton. As the wrapped brane passes by localized sources or features along its inflationary trajectory in the extra dimensional space, the KK modes along the wrapped direction are excited and start to oscillate during inflation. We show that the oscillating KK modes induce parametric resonance for the curvature perturbations, generating sharp signals in the perturbation spectrum. The effective four dimensional picture is a theory where the inflaton couples to the heavy KK modes. The Nambu-Goto action of the brane sources couplings between the inflaton kinetic terms and the KK modes, which trigger significant resonant amplification of the curvature perturbations. We find that the strong resonant effects are localized to narrow wave number ranges, producing spikes in the perturbation spectrum. Investigation of such resonant signals opens up the possibility of probing the extra dimensional space through cosmological observations.
- OSTI ID:
- 22283005
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2013, Issue 02; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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