Predictions of quantum gravity in inflationary cosmology: effects of the Weyl-squared term - Archive ouverte HAL Access content directly
Journal Articles Journal of High Energy Physics Year : 2020

Predictions of quantum gravity in inflationary cosmology: effects of the Weyl-squared term

Abstract

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 $R+R^{2}$ 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 ($m_{\chi }>m_{\phi }/4$) on the mass $m_{\chi }$ of the fakeon with respect to the mass $m_{\phi }$ of the inflaton. The tensor-to-scalar ratio $r$ is predicted within less than an order of magnitude ($4/3 < N^{2}r<12$ to the leading order in the number of $e$-foldings $N$). Moreover, the relation $r\simeq -8n_{T}$ is not affected by the Weyl-squared term. No vector and no other scalar/tensor degree of freedom is present.

Dates and versions

hal-03059912 , version 1 (13-12-2020)

Identifiers

Cite

Damiano Anselmi, Eugenio Bianchi, Marco Piva. Predictions of quantum gravity in inflationary cosmology: effects of the Weyl-squared term. Journal of High Energy Physics, 2020, 2020 (7), ⟨10.1007/JHEP07(2020)211⟩. ⟨hal-03059912⟩
16 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More