Pre-inflationary vacuum in the cosmic microwave background

2006/12/31 by Brian A. Powell, William H. Kinney · 4 citations
Earth and Planetary Sciences · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #astro-ph

paper · pdf · doi:10.1103/physrevd.76.063512

published as Phys.Rev.D76:063512,2007 · 4 pages, 2 figures, references added. Version submitted to PRL. (v3: 9 pages, 4 figures, detailed justification of Eq. 11 of v2. Version accepted for publication by PRD.)

arxiv created 2007/08/09 · openalex publication_date 2007/09/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We consider the effects on the primordial power spectrum of a period of radiation-dominated expansion prior to the inflationary era. If inflation lasts a total of only 60 e-folds or so, the boundary condition for quantum modes cannot be taken in the short-wavelength limit as in the standard perturbation calculation. Instead, the boundary condition is set by the vacuum state of the prior radiation-dominated epoch, which only corresponds to the inflationary vacuum state in the ultraviolet limit. This altered vacuum state results in a modulation of the inflationary power spectrum. We calculate the modification to a best-fit model from the WMAP3 data set, and find that power is suppressed at large scales. The modified power spectrum is favored only very weakly by the WMAP3 temperature and polarization data.

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