2019/09/30 by Renata Kallosh, Andrei Linde
Physics and Astronomy · #hep-th #astro-ph.CO #gr-qc #hep-ph
paper · pdf · doi:10.1103/physrevd.100.123523
published as Phys. Rev. D 100, 123523 (2019) · 20 pages, 11 figures. few typos corrected
arxiv created 2021/10/25 · arxiv updated 2021/10/26
We show that a combination of the simplest α-attractors and KKLTI models related to Dp-brane inflation covers most of the area in the (ns, r) space favored by Planck 2018. For α-attractor models, there are discrete targets 3α=1,2,...,7, predicting 7 different values of r = 12α/N2 in the range 10-2 \gtrsim r \gtrsim 10-3. In the small r limit, α-attractors and Dp-brane inflation models describe vertical β-stripes in the (ns, r) space, with ns=1-β/N, β=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 1σ area in the (ns, r) space favored by Planck 2018 can be covered models with β= 2 and β= 5/3. Future precision data on ns may help to discriminate between these models even if the precision of the measurement of r is insufficient for the discovery of gravitational waves produced during inflation.