On the accuracy of slow-roll inflation given current observational constraints

dc.creatorMakarov, Alexey
dc.date2005-06-14
dc.date2005-10-19
dc.date.accessioned2026-07-07T06:37:12Z
dc.date.available2026-07-07T06:37:12Z
dc.descriptionWe investigate the accuracy of slow-roll inflation in light of current observational constraints, which do not allow for a large deviation from scale invariance. We investigate the applicability of the first and second order slow-roll approximations for inflationary models, including those with large running of the scalar spectral index. We compare the full numerical solutions with those given by the first and second order slow-roll formulae. We find that even first order slow-roll is generally accurate; the largest deviations arise in models with large running where the error in the power spectrum can be at the level of 1-2%. Most of this error comes from inaccuracy in the calculation of the slope and not of the running or higher order terms. Second order slow-roll does not improve the accuracy over first order. We also argue that in the basis $ε_0=1/H$, $ε_{n+1}={d\ln|ε_n|}/{dN}$, introduced by Schwarz et al. (2001), slow-roll does not require all of the parameters to be small. For example, even a divergent $ε_3$ leads to finite solutions which are accurately described by a slow-roll approximation. Finally, we argue that power spectrum parametrization recently introduced by Abazaijan, Kadota and Stewart does not work for models where spectral index changes from red to blue, while the usual Taylor expansion remains a good approximation.
dc.descriptionMatches the published PRD version; added comments on Abazaijan, Kadota and Stewart (2005) parameterization
dc.identifierhttps://arxiv.org/abs/astro-ph/0506326
dc.identifierhttp://arxiv.org/abs/astro-ph/0506326
dc.identifierPhys.Rev. D72 (2005) 083517
dc.identifierdoi:10.1103/PhysRevD.72.083517
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/100309
dc.subjectAstrophysics
dc.subjectGeneral Relativity and Quantum Cosmology
dc.subjectHigh Energy Physics - Theory
dc.titleOn the accuracy of slow-roll inflation given current observational constraints
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