Inflationary paradigm in trouble after Planck2013
Abstract
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.
- Publication:
-
Physics Letters B
- Pub Date:
- June 2013
- DOI:
- 10.1016/j.physletb.2013.05.023
- arXiv:
- arXiv:1304.2785
- Bibcode:
- 2013PhLB..723..261I
- Keywords:
-
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- 6 pages, 1 figure, accepted for publication in Phys.Lett.B