Primordial standing waves

File Description SizeFormat 
1711.05539-2.pdfAccepted version115.3 kBAdobe PDFView/Open
Title: Primordial standing waves
Authors: Gubitosi, G
Magueijo, J
Item Type: Journal Article
Abstract: We consider the possibility that the primordial fluctuations (scalar and tensor) might have been standing waves at their moment of creation, whether or not they had a quantum origin. We lay down the general conditions for spatial translational invariance, and isolate the pieces of the most general such theory that comply with, or break translational symmetry. We find that, in order to characterize statistically translationally invariant standing waves, it is essential to consider the correlator ⟨c0(k)c0(k′)⟩ in addition to the better known ⟨c0(k)c†0(k′)⟩ [where c0(k) are the complex amplitudes of traveling waves]. We then examine how the standard process of “squeezing” (responsible for converting traveling waves into standing waves while the fluctuations are outside the horizon) reacts to being fed primordial standing waves. For translationally invariant systems only one type of standing wave, with the correct temporal phase (the “sine wave”), survives squeezing. Primordial standing waves might therefore be invisible at late times—or not—depending on their phase. Theories with modified dispersion relations behave differently in this respect, since only standing waves with the opposite temporal phase survive at late times.
Issue Date: 12-Mar-2018
Date of Acceptance: 1-Mar-2018
ISSN: 2470-0010
Publisher: American Physical Society
Journal / Book Title: PHYSICAL REVIEW D
Volume: 97
Issue: 6
Copyright Statement: © 2018 American Physical Society
Sponsor/Funder: Science and Technology Facilities Council (STFC)
John Templeton Foundation
Funder's Grant Number: ST/L00044X/1
Keywords: Science & Technology
Physical Sciences
Astronomy & Astrophysics
Physics, Particles & Fields
Publication Status: Published
Article Number: ARTN 063509
Appears in Collections:Physics
Theoretical Physics
Faculty of Natural Sciences

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commonsx