Paper detail

The twilight of the single field slow rolling inflaton

We present an study from PLANCK2013+WP+BAO:$Λ$CDM+$r$+$α_s$ data, where 49 slow roll inflationary potentials are tested, showing that the theoretical value of the running provided by 48 of these potentials has a deviation to the expected observational value larger than $1.6σ$, and its modulus is smaller than the modulus of the expected observational one, what disfavours these models at 94.5 \% of Confidence Level (C.L.), concluding from these results that, inflationary cosmology may require multiple fields or a breakdown of slow roll condition. This conclusion has drastically changed with the last data provided by PLANCK2015 where the modulus of the expected observational value of the running has been reduced one order, getting shorter the distance to its theoretical value $1σ$ or more, what allows the viability of the majority of the potentials disfavored by the running provided by PLANCK2013 data. However if one takes into account the running of the running, its theoretical value, which in the slow roll regime depends on the slow roll parameters at third order, is incompatible with the expected observational value provided by PLANCK2013 and PLANCK2015, disfavouring at 92.8 \% C.L. or more, 39 of the 49 slow roll potentials tested. Moreover, if one restricts the number of e-folds to be between 30 and 80, then only two potentials will survive to this test.