title: ϕ(2) or not ϕ(2): testing the simplest inflationary potential.
abstract: The simplest inflationary model V=1/2m(2)ϕ(2) represents the benchmark for future constraints. For a quadratic potential, the quantity (n(s)-1)+r/4+11(n(s)-1)(2)/24 vanishes (up to corrections which are cubic in slow roll) and can be used to parametrize small deviations from the minimal scenario. Future constraints on this quantity will be able to distinguish a quadratic potential from a pseudo-Nambu-Goldstone boson with f≲30M(pl) and set limits on the deviation from unity of the speed of sound |c(s)-1|≲3×10(-2) (corresponding to an energy scale Λ≳2×10(16)  GeV) and on the contribution of a second field to perturbations (≲6×10(-2)). The limiting factor for these bounds will be the uncertainty on the spectral index. The error on the number of e-folds will be ΔN≃0.4, corresponding to an error on the reheating temperature ΔT(rh)/T(rh)≃1.2. We comment on the relevance of non-Gaussianity after BICEP2 results.
authors.affiliation: Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy and Institute for Advanced Study, Princeton, New Jersey 08540, USA.
authors.forename: Paolo
authors.initials: P
authors.lastname: Creminelli
authors.affiliation: Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy and Departamento de Física and IFIBA, FCEyN UBA, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellón I, 1428 Buenos Aires, Argentina.
authors.forename: Diana
authors.initials: D
authors.lastname: López Nacir
authors.affiliation: SISSA, via Bonomea 265, 34136 Trieste, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34136 Trieste, Italy.
authors.forename: Marko
authors.initials: M
authors.lastname: Simonović
authors.affiliation: SISSA, via Bonomea 265, 34136 Trieste, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34136 Trieste, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Trevisan
authors.affiliation: Institute for Advanced Study, Princeton, New Jersey 08540, USA.
authors.forename: Matias
authors.initials: M
authors.lastname: Zaldarriaga