TY - JOUR

T1 - Predictions of quantum gravity in inflationary cosmology

T2 - effects of the Weyl-squared term

AU - Anselmi, Damiano

AU - Bianchi, Eugenio

AU - Piva, Marco

N1 - Funding Information:
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited
Publisher Copyright:
© 2020, The Author(s).

PY - 2020/7/1

Y1 - 2020/7/1

N2 - We derive the predictions of quantum gravity with fakeons on the amplitudes and spectral indices of the scalar and tensor fluctuations in inflationary cosmology. The action is R +R2 plus the Weyl-squared term. The ghost is eliminated by turning it into a fakeon, that is to say a purely virtual particle. We work to the next-to-leading order of the expansion around the de Sitter background. The consistency of the approach puts a lower bound (mχ > mϕ /4) on the mass mχ of the fakeon with respect to the mass mϕ of the inflaton. The tensor-to-scalar ratio r is predicted within less than an order of magnitude (4/2 < N2r <12 to the leading order in the number of e-foldings N). Moreover, the relation r ≃ –8nT is not affected by the Weyl-squared term. No vector and no other scalar/tensor degree of freedom is present.

AB - We derive the predictions of quantum gravity with fakeons on the amplitudes and spectral indices of the scalar and tensor fluctuations in inflationary cosmology. The action is R +R2 plus the Weyl-squared term. The ghost is eliminated by turning it into a fakeon, that is to say a purely virtual particle. We work to the next-to-leading order of the expansion around the de Sitter background. The consistency of the approach puts a lower bound (mχ > mϕ /4) on the mass mχ of the fakeon with respect to the mass mϕ of the inflaton. The tensor-to-scalar ratio r is predicted within less than an order of magnitude (4/2 < N2r <12 to the leading order in the number of e-foldings N). Moreover, the relation r ≃ –8nT is not affected by the Weyl-squared term. No vector and no other scalar/tensor degree of freedom is present.

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U2 - 10.1007/JHEP07(2020)211

DO - 10.1007/JHEP07(2020)211

M3 - Article

AN - SCOPUS:85088798276

SN - 1126-6708

VL - 2020

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 7

M1 - 211

ER -