TY - JOUR
T1 - Inflationary paradigm in trouble after Planck2013
AU - Ijjas, Anna
AU - Steinhardt, Paul J.
AU - Loeb, Abraham
N1 - Funding Information:
We thank T. Baker, W. Jones, J. Kovac, J.-L. Lehners, D. Spergel, and B. Xue for helpful discussions. This work was supported in part by the US Department of Energy grant DE-FG02-91ER40671 (P.J.S.) and by NSF grant AST-0907890 and NASA grants NNX08AL43G and NNA09DB30A (A.L.). A.I. gratefully acknowledges the support of the Fritz Thyssen Foundation . P.J.S. is grateful to the Simons Foundation and the Radcliffe Institute for providing support during his leave at Harvard and to the Institute for Theory and Computation at the Harvard–Smithsonian for hosting him during the period that this work was done.
PY - 2013/6/25
Y1 - 2013/6/25
N2 - 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.
AB - 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.
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U2 - 10.1016/j.physletb.2013.05.023
DO - 10.1016/j.physletb.2013.05.023
M3 - Article
AN - SCOPUS:84878906806
SN - 0370-2693
VL - 723
SP - 261
EP - 266
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
IS - 4-5
ER -