Towards the physical vacuum of cosmic inflation

There have been long debates about the initial conditions of inflationary perturbations. In this work we explicitly show the decay of excited states during inflation via interactions from the renormalization group point of view. For this purpose, we note that the folded shape non-Gaussianity can be...

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Main Authors: Hongliang Jiang, Yi Wang
Format: Article
Language:English
Published: Elsevier 2016-09-01
Series:Physics Letters B
Online Access:http://www.sciencedirect.com/science/article/pii/S037026931630329X
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spelling doaj-0c71bbdad9cc4aad8db40cd0d15875fa2020-11-25T00:01:36ZengElsevierPhysics Letters B0370-26931873-24452016-09-01760C20220610.1016/j.physletb.2016.06.069Towards the physical vacuum of cosmic inflationHongliang JiangYi WangThere have been long debates about the initial conditions of inflationary perturbations. In this work we explicitly show the decay of excited states during inflation via interactions from the renormalization group point of view. For this purpose, we note that the folded shape non-Gaussianity can be interpreted as the decay of the non-Bunch–Davies initial condition. The one loop diagrams with non-Bunch–Davies propagators are calculated to uncover the decay of such excited states. We find that the decay of amplitude is contributed by the folded shape of loop momentum and is irrelevant to the UV part. The conformal decay rate is related to the strength of non-Gaussianity via Γ∼(fNLλ)2Pζk5O(τ4,τ04). The observed smallness of non-Gaussianity keeps the window open for probing inflationary initial conditions and trans-Planckian physics.http://www.sciencedirect.com/science/article/pii/S037026931630329X
collection DOAJ
language English
format Article
sources DOAJ
author Hongliang Jiang
Yi Wang
spellingShingle Hongliang Jiang
Yi Wang
Towards the physical vacuum of cosmic inflation
Physics Letters B
author_facet Hongliang Jiang
Yi Wang
author_sort Hongliang Jiang
title Towards the physical vacuum of cosmic inflation
title_short Towards the physical vacuum of cosmic inflation
title_full Towards the physical vacuum of cosmic inflation
title_fullStr Towards the physical vacuum of cosmic inflation
title_full_unstemmed Towards the physical vacuum of cosmic inflation
title_sort towards the physical vacuum of cosmic inflation
publisher Elsevier
series Physics Letters B
issn 0370-2693
1873-2445
publishDate 2016-09-01
description There have been long debates about the initial conditions of inflationary perturbations. In this work we explicitly show the decay of excited states during inflation via interactions from the renormalization group point of view. For this purpose, we note that the folded shape non-Gaussianity can be interpreted as the decay of the non-Bunch–Davies initial condition. The one loop diagrams with non-Bunch–Davies propagators are calculated to uncover the decay of such excited states. We find that the decay of amplitude is contributed by the folded shape of loop momentum and is irrelevant to the UV part. The conformal decay rate is related to the strength of non-Gaussianity via Γ∼(fNLλ)2Pζk5O(τ4,τ04). The observed smallness of non-Gaussianity keeps the window open for probing inflationary initial conditions and trans-Planckian physics.
url http://www.sciencedirect.com/science/article/pii/S037026931630329X
work_keys_str_mv AT hongliangjiang towardsthephysicalvacuumofcosmicinflation
AT yiwang towardsthephysicalvacuumofcosmicinflation
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