Unsqueezing of standing waves due to inflationary domain structure

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Title: Unsqueezing of standing waves due to inflationary domain structure
Authors: Contaldi, CR
Magueijo, J
Item Type: Journal Article
Abstract: The so-called trans-Planckian problem of inflation may be evaded by positing that modes come into existence only when they became “cis-Planckian” by virtue of expansion. However, this would imply that for any mode a new random realization would have to be drawn every N wavelengths, with N typically of order 1000 (but it could be larger or smaller). Such a redrawing of realizations leads to a heteroskodastic distribution if the region under observation contains several such independent domains. This has no effect on the sampled power spectrum for a scale-invariant raw spectrum, but at very small scales, it leads to a spectral index bias toward scale invariance and smooths oscillations in the spectrum. The domain structure would also “unsqueeze” some of the propagating waves, i.e., dismantle their standing wave character. By describing standing waves as traveling waves of the same amplitude moving in opposite directions, we determine the observational effects of unsqueezing. We find that it would erase the Doppler peaks in the cosmic microwave background, but only on very small angular scales, in which the primordial signal may not be readily accessible. The standing waves in a primordial gravitational wave background would also be turned into traveling waves. This unsqueezing of the gravitational wave background may constitute a detectable phenomenon.
Issue Date: 15-Aug-2018
Date of Acceptance: 1-Aug-2018
ISSN: 2470-0010
Publisher: American Physical Society
Journal / Book Title: Physical Review D
Volume: 98
Issue: 4
Copyright Statement: © 2018 American Physical Society
Sponsor/Funder: Science and Technology Facilities Council
Science and Technology Facilities Council (STFC)
Funder's Grant Number: ST-N000838
Keywords: Science & Technology
Physical Sciences
Astronomy & Astrophysics
Physics, Particles & Fields
Publication Status: Published
Open Access location:
Article Number: 043523
Online Publication Date: 2018-08-21
Appears in Collections:Physics
Theoretical Physics
Faculty of Natural Sciences

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