Quantum fluctuations and CMB anisotropies in one-bubble open inflation models

Yamamoto, Kazuhiro; Sasaki, Misao; Tanaka, Takahiro

doi:10.1103/physrevd.54.5031

Cited by 62 publications

(148 citation statements)

References 44 publications

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“…Although this is a novel feature in the context of inflationary tensor perturbations, it is not surprising. In conventional open inflationary scenarios for instance, the coupling of scalar field fluctuations with scalar metric perturbations introduces a supercurvature mode with an eigenvalue of the Laplacian close to the discrete de Sitter gauge mode [42,35]. The former discrete mode at p ′ = iΛ 1 ∼ 3i/2 in equation 3.66 is nothing else than the analogue of this well known supercurvature mode in the scalar fluctuation spectrum.…”

Section: Resultsmentioning

confidence: 99%

Brane new world

2000

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We study a Randall-Sundrum cosmological scenario consisting of a domain wall in anti-de Sitter space with a strongly coupled large N conformal field theory living on the wall. The AdS/CFT correspondence allows a fully quantum mechanical treatment of this CFT, in contrast with the usual treatment of matter fields in inflationary cosmology. The conformal anomaly of the CFT provides an effective tension which leads to a de Sitter geometry for the domain wall. This is the analogue of Starobinsky's four dimensional model of anomaly driven inflation. Studying this model in a Euclidean setting gives a natural choice of boundary conditions at the horizon. We calculate the graviton correlator using the Hartle-Hawking "No Boundary" proposal and analytically continue to Lorentzian signature. We find that the CFT strongly suppresses metric perturbations on all but the largest angular scales. This is true independently of how the de Sitter geometry arises, i.e., it is also true for four dimensional Einstein gravity. Since generic matter would be expected to behave like a CFT on small scales, our results suggest that tensor perturbations on small scales are far smaller than predicted by all previous calculations, which have neglected the effects of matter on tensor perturbations.

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Section: Resultsmentioning

confidence: 99%

Brane new world

2000

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“…(3), and hence the field perturbations of have the same form as computed in Ref. [24]. This gives a curvaton spectrum featuring a sharp supercurvature spike and a nearly scaleinvariant subcurvature spectrum, as required for a successful modulation scenario.…”

Section: 111302 (2013) P H Y S I C a L R E V I E W L E T T E R Smentioning

confidence: 68%

“…Moreover, it was discovered that open inflation models typically excite a single one of those modes, whose amplitude can be found by matching the pretunneling quantum fluctuations across the bubble wall into the open universe. If the vacuum energy density before tunneling is much greater than that immediately afterward, the amplitude of the supercurvature mode may be much higher than that of the subsequently generated spectrum of subcurvature modes which provide the main contribution to CMB anisotropies on all scales [24]. Hence, such models give exactly the type of power spectrum phenomenology required by the modulation scenario.…”

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confidence: 92%

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Is the Lopsided Universe an Open Universe?

Kamionkowski¹

2013

Physics

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We argue that the observed large-scale cosmic microwave anomalies, discovered by WMAP and confirmed by the Planck satellite, are most naturally explained in the context of a marginally open universe. Particular focus is placed on the dipole power asymmetry, via an open universe implementation of the large-scale gradient mechanism of Erickcek et al. Open inflation models, which are motivated by the string landscape and which can excite ''supercurvature'' perturbation modes, can explain the presence of a very-large-scale perturbation that leads to a dipole modulation of the power spectrum measured by a typical observer. We provide a specific implementation of the scenario which appears compatible with all existing constraints.

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“…for the 3-dimensional scalar mode, and 27) for the 3-dimensional vector mode. When we require the normalization condition eq.…”

Section: Even Parity Modesmentioning

confidence: 99%

Is there supercurvature mode of massive vector field in open inflation?

Yamauchi

Fujita

Mukohyama

2014

J. Cosmol. Astropart. Phys.

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Abstract. We investigate the Euclidean vacuum mode functions of a massive vector field in a spatially open chart of de Sitter spacetime. In the one-bubble open inflationary scenario that naturally predicts a negative spatial curvature after a quantum tunneling, it is known that a light scalar field has the so-called supercurvature mode, i.e. an additional discrete mode which describes fluctuations over scales larger than the spatial curvature scale. If such supercurvature modes exist for a vector field with a sufficiently light mass, then they would decay slower and easily survive the inflationary era. However, the existence of supercurvature mode strongly depends on details of the system. To clarify whether a massive vector field has supercurvature modes, we consider a U(1) gauge field with gauge and conformal invariances spontaneously broken through the Higgs mechanism, and present explicit expressions for the Euclidean vacuum mode functions. We find that, for any values of the vector field mass, there is no supercurvature mode. In the massless limit, the absence of supercurvature modes in the scalar sector stems from the gauge symmetry.

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Quantum fluctuations and CMB anisotropies in one-bubble open inflation models

Cited by 62 publications

References 44 publications

Brane new world

Brane new world

Is the Lopsided Universe an Open Universe?

Is there supercurvature mode of massive vector field in open inflation?

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