2013/04/30 by Anna Ijjas, Paul J. Steinhardt, Abraham Loeb · 3 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Particle physics theoretical and experimental studies #astro-ph.CO #hep-ph #hep-th
paper · pdf · doi:10.1016/j.physletb.2013.05.023
published as Phys.Lett.B 723 (2013) 261-266 · 6 pages, 1 figure, accepted for publication in Phys.Lett.B
openalex publication_date 2013/05/14 · arxiv created 2013/06/01 · arxiv updated 2013/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Recent results from the Planck satellite combined with earlier observations from WMAP, ACT, SPT and other experiments eliminate a wide spectrum of more complex inflationary models and favor models with a single scalar field, as reported by the Planck Collaboration. More important, though, is that all the simplest inflaton models are disfavored statistically relative to those with plateau-like potentials. We discuss how a restriction to plateau-like models has three independent serious drawbacks: it exacerbates both the initial conditions problem and the multiverse-unpredictability problem and it creates a new difficulty that we call the inflationary "unlikeliness problem." Finally, we comment on problems reconciling inflation with a standard model Higgs, as suggested by recent LHC results. In sum, we find that recent experimental data disfavors all the best-motivated inflationary scenarios and introduces new, serious difficulties that cut to the core of the inflationary paradigm. Forthcoming searches for B-modes, non-Gaussianity and new particles should be decisive.