English

CMB targets after the latest Planck data release

High Energy Physics - Theory 2021-10-26 v4 Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Phenomenology

Abstract

We show that a combination of the simplest α\alpha-attractors and KKLTI models related to Dp-brane inflation covers most of the area in the (nsn_{s}, rr) space favored by Planck 2018. For α\alpha-attractor models, there are discrete targets 3α=1,2,...,73\alpha=1,2,...,7, predicting 7 different values of r=12α/N2r = 12\alpha/N^{2} in the range 102r10310^{-2} \gtrsim r \gtrsim 10^{-3}. In the small rr limit, α\alpha-attractors and Dp-brane inflation models describe vertical β\beta-stripes in the (nsn_{s}, rr) space, with ns=1β/Nn_{s}=1-\beta/N, β=2,53,85,32,43\beta=2, {5\over 3},{8\over 5}, {3\over 2},{4\over 3}. A phenomenological description of these models and their generalizations can be achieved in the context of pole inflation. Most of the 1σ1\sigma area in the (nsn_{s}, rr) space favored by Planck 2018 can be covered models with β=2\beta = 2 and β=5/3\beta = 5/3. Future precision data on nsn_s may help to discriminate between these models even if the precision of the measurement of rr is insufficient for the discovery of gravitational waves produced during inflation.

Keywords

Cite

@article{arxiv.1909.04687,
  title  = {CMB targets after the latest Planck data release},
  author = {Renata Kallosh and Andrei Linde},
  journal= {arXiv preprint arXiv:1909.04687},
  year   = {2021}
}

Comments

20 pages, 11 figures. few typos corrected

R2 v1 2026-06-23T11:11:35.518Z