Quantum field theory in de Sitter space: renormalization by point-splitting

Bunch, T S; Davies, Paul

doi:10.1098/rspa.1978.0060

Cited by 1,068 publications

(503 citation statements)

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“…The mode in (2.11) is generally called the adiabatic mode, which in curved space in many instances is the closest to the usual definition of vacuum in Minkowski space [59,73]. The "in" solution (2.8) can be recognized as the Bunch-Davies vacuum [74,75]. Its asymptotic behavior as k ph → ∞ coincides with the adiabatic mode (2.11), which implies that it is the solution that describes a mode that was in the vacuum at early times.…”

Section: Jhep01(2017)133mentioning

confidence: 99%

Massive scalar field evolution in de Sitter

Markkanen

Rajantie

2017

J. High Energ. Phys.

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The behaviour of a massive, non-interacting and non-minimally coupled quantised scalar field in an expanding de Sitter background is investigated by solving the field evolution for an arbitrary initial state. In this approach there is no need to choose a vacuum in order to provide a definition for particle states, nor to introduce an explicit ultraviolet regularization. We conclude that the expanding de Sitter space is a stable equilibrium configuration under small perturbations of the initial conditions. Depending on the initial state, the energy density can approach its asymptotic value from above or below, the latter of which implies a violation of the weak energy condition. The backreaction of the quantum corrections can therefore lead to a phase of super-acceleration also in the non-interacting massive case.

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Section: Jhep01(2017)133mentioning

confidence: 99%

Massive scalar field evolution in de Sitter

Markkanen

Rajantie

2017

J. High Energ. Phys.

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“…A much more stringent constraint is obtained from the requirement that the field φ is effectively massless during (at least) the last 50 − 60 inflationary e-foldings so that it receives a superhorizon spectrum of perturbations [42] …”

Section: The Pq Field As Curvatonmentioning

confidence: 99%

The Peccei-Quinn field as curvaton

Dimopoulos

Lazarides

Lyth

et al. 2003

J. High Energy Phys.

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A simple extension of the minimal supersymmetric standard model which naturally and simultaneously solves the strong CP and µ problems via a PecceiQuinn and a continuous R symmetry is considered. This model is supplemented with hybrid inflation and leptogenesis, but without taking the specific details of these scenarios. It is shown that the Peccei-Quinn field can successfully act as a curvaton generating the total curvature perturbation in the universe in accord with the cosmic background explorer measurements. A crucial phenomenon, which assists us to achieve this, is the 'tachyonic amplification' of the perturbation acquired by this field during inflation if the field, in its subsequent evolution, happens to be stabilized for a while near a maximum of the potential. In this case, the contribution of the field to the total energy density is also enhanced ('tachyonic effect'), which helps too. The cold dark matter in the universe consists, in this model, mainly of axions which carry an isocurvature perturbation uncorrelated with the total curvature perturbation. There are also lightest sparticles (neutralinos) which, like the baryons, originate from the inflationary reheating and, thus, acquire an isocurvature perturbation fully correlated with the curvature perturbation. So, the overall isocurvature perturbation has a mixed correlation with the adiabatic one. It is shown that the presently available bound on such an isocurvature perturbation from cosmic microwave background radiation and other data is satisfied. Also, the constraint on the non-Gaussianity of the curvature perturbation obtained from the recent Wilkinson microwave anisotropy probe data is fulfilled thanks to the 'tachyonic effect'.

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“…At first sight this seems hard to imagine, as the Bunch-Davies/HartleHawking vacuum wave function of a massless free scalar is an almost trivial Gaussian at all times [16,17]. Nevertheless, we will show in this paper that it emerges in a very sharp sense.…”

Section: Jhep06(2016)181mentioning

confidence: 88%

“…We can however approximate its logarithm by an integral, taking into account the momentum quantization k i ∈ 2π L Z: 16) where for dS d+1 in the late time limit η 0 → 0, according to (3.9), we have β(k) = The chosen value of the IR cutoff β 0 corresponds to k 0 ≡ 2π L . This integral is easily computed, and we can evaluate the inverse Laplace transform again in saddle point approximation, yielding again a Gumbel distribution: with ψ the digamma function.…”

Section: Ds D+1mentioning

confidence: 99%

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Cosmic clustering

Anninos

Denef

2016

J. High Energ. Phys.

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We show that the late time Hartle-Hawking wave function for a free massless scalar in a fixed de Sitter background encodes a sharp ultrametric structure for the standard Euclidean distance on the space of field configurations. This implies a hierarchical, tree-like organization of the state space, reflecting its genesis as a branched diffusion process. An equivalent mathematical structure organizes the state space of the Sherrington-Kirkpatrick model of a spin glass.

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Quantum field theory in de Sitter space: renormalization by point-splitting

Cited by 1,068 publications

References 7 publications

Massive scalar field evolution in de Sitter

Massive scalar field evolution in de Sitter

The Peccei-Quinn field as curvaton

Cosmic clustering

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