Asymptotic symmetries in de Sitter and inflationary spacetimes

Ricardo J. Z. Ferreira, McCullen Sandora, Martin S. Sloth

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Abstract

Soft gravitons produced by the expansion of de Sitter can be viewed as the Nambu-Goldstone bosons of spontaneously broken asymptotic symmetries of the de Sitter spacetime. We explicitly construct the associated charges, and show that acting with the charges on the vacuum creates a new state equivalent to a change in the local coordinates induced by the soft graviton. While the effect remains unobservable within the domain of a single observer where the symmetry is unbroken, this change is physical when comparing different asymptotic observers, or between a transformed and un-transformed initial state, consistent with the scale-dependent statistical anisotropies previously derived using semiclassical relations. We then compute the overlap, (0| 0′), between the unperturbed de Sitter vacuum |0), and the state

Original languageEnglish
Article number033
JournalJournal of Cosmology and Astroparticle Physics
Volume2017
Issue number4
Number of pages35
ISSN1475-7516
DOIs
Publication statusPublished - 2017

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gravitons
vacuum
symmetry
bosons
anisotropy
expansion

Keywords

  • gravity
  • ination
  • physics of the early universe

Cite this

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title = "Asymptotic symmetries in de Sitter and inflationary spacetimes",
abstract = "Soft gravitons produced by the expansion of de Sitter can be viewed as the Nambu-Goldstone bosons of spontaneously broken asymptotic symmetries of the de Sitter spacetime. We explicitly construct the associated charges, and show that acting with the charges on the vacuum creates a new state equivalent to a change in the local coordinates induced by the soft graviton. While the effect remains unobservable within the domain of a single observer where the symmetry is unbroken, this change is physical when comparing different asymptotic observers, or between a transformed and un-transformed initial state, consistent with the scale-dependent statistical anisotropies previously derived using semiclassical relations. We then compute the overlap, (0| 0′), between the unperturbed de Sitter vacuum |0), and the state",
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Asymptotic symmetries in de Sitter and inflationary spacetimes. / Ferreira, Ricardo J. Z. ; Sandora, McCullen; Sloth, Martin S.

In: Journal of Cosmology and Astroparticle Physics, Vol. 2017, No. 4, 033, 2017.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Asymptotic symmetries in de Sitter and inflationary spacetimes

AU - Ferreira, Ricardo J. Z.

AU - Sandora, McCullen

AU - Sloth, Martin S.

PY - 2017

Y1 - 2017

N2 - Soft gravitons produced by the expansion of de Sitter can be viewed as the Nambu-Goldstone bosons of spontaneously broken asymptotic symmetries of the de Sitter spacetime. We explicitly construct the associated charges, and show that acting with the charges on the vacuum creates a new state equivalent to a change in the local coordinates induced by the soft graviton. While the effect remains unobservable within the domain of a single observer where the symmetry is unbroken, this change is physical when comparing different asymptotic observers, or between a transformed and un-transformed initial state, consistent with the scale-dependent statistical anisotropies previously derived using semiclassical relations. We then compute the overlap, (0| 0′), between the unperturbed de Sitter vacuum |0), and the state

AB - Soft gravitons produced by the expansion of de Sitter can be viewed as the Nambu-Goldstone bosons of spontaneously broken asymptotic symmetries of the de Sitter spacetime. We explicitly construct the associated charges, and show that acting with the charges on the vacuum creates a new state equivalent to a change in the local coordinates induced by the soft graviton. While the effect remains unobservable within the domain of a single observer where the symmetry is unbroken, this change is physical when comparing different asymptotic observers, or between a transformed and un-transformed initial state, consistent with the scale-dependent statistical anisotropies previously derived using semiclassical relations. We then compute the overlap, (0| 0′), between the unperturbed de Sitter vacuum |0), and the state

KW - gravity

KW - ination

KW - physics of the early universe

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DO - 10.1088/1475-7516/2017/04/033

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JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

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