Large non-Gaussianities in single-field inflation

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dc.contributor.author Chen, X en
dc.contributor.author Easther, Richard en
dc.contributor.author Lim, EA en
dc.date.accessioned 2012-04-02T00:48:34Z en
dc.date.issued 2006-11-22 en
dc.identifier.citation JCAP 2007(6):1-20 22 Nov 2006 en
dc.identifier.issn 1475-7516 en
dc.identifier.uri http://hdl.handle.net/2292/16320 en
dc.description.abstract We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which contribute to the 3-point function. Consequently, we can analyze models where the potential has a "feature", in the vicinity of which the slow roll parameters may take on large, transient values. This introduces both scale and shape dependent non-Gaussianities into the primordial perturbations. As an example of our methodology, we examine the ``step'' potentials which have been invoked to improve the fit to the glitch in the $<TT>$ $C_l$ for $l \sim 30$, present in both the one and three year WMAP data sets. We show that for the typical parameter values, the non-Gaussianities associated with the step are far larger than those in standard slow roll inflation, and may even be within reach of a next generation CMB experiment such as Planck. More generally, we use this example to explain that while adding features to potential can improve the fit to the 2-point function, these are generically associated with a greatly enhanced signal at the 3-point level. Moreover, this 3-point signal will have a very nontrivial shape and scale dependence, which is correlated with the form of the 2-point function, and may thus lead to a consistency check on the models of inflation with non-smooth potentials. en
dc.publisher IOP Publishing Ltd; SISSA en
dc.relation.ispartofseries Journal of Cosmology and Astroparticle Physics en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. en
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.title Large non-Gaussianities in single-field inflation en
dc.type Journal Article en
dc.identifier.doi 10.1088/1475-7516/2007/06/023 en
pubs.issue 6 en
pubs.begin-page 1 en
pubs.volume 2007 en
dc.rights.holder Copyright: IOP Publishing Ltd; SISSA en
pubs.author-url http://arxiv.org/abs/astro-ph/0611645v3 en
pubs.end-page 20 en
dc.rights.accessrights http://purl.org/eprint/accessRights/RestrictedAccess en
pubs.subtype Article en
pubs.elements-id 264319 en
pubs.org-id Science en
pubs.org-id Physics en
pubs.arxiv-id astro-ph/0611645 en
pubs.record-created-at-source-date 2012-04-02 en


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