@article{25bb6ce7548f4e20b8858e44750450f1,
title = "Shapes and features of the primordial bispectrum",
abstract = "If time-dependent disruptions from slow-roll occur during inflation, the correlation functions of the primordial curvature perturbation should have scale-dependent features, a case which is marginally supported from the cosmic microwave background (CMB) data. We offer a new approach to analyze the appearance of such features in the primordial bispectrum that yields new consistency relations and justifies the search of oscillating patterns modulated by orthogonal and local templates. Under the assumption of sharp features, we find that the cubic couplings of the curvature perturbation can be expressed in terms of the bispectrum in two specific momentum configurations, for example local and equilateral. This allows us to derive consistency relations among different bispectrum shapes, which in principle could be tested in future CMB surveys. Furthermore, based on the form of the consistency relations, we construct new two-parameter templates for features that include all the known shapes.",
keywords = "cosmological perturbation theory, inflation, non-gaussianity",
author = "Gong, {Jinn Ouk} and Palma, {Gonzalo A.} and Spyros Sypsas",
note = "Funding Information: TJ Park Science Fellowship of POSCO TJ Park Foundation and the Basic Science Research Program through the National Research Foundation of Korea Research Grant NRF-2016R1D1A1B03930408. GAP is supported by the Fondecyt project 1171811. SS is supported by the Fondecyt 2016 Post-doctoral Grant 3160299. Funding Information: Groups at the Asia Pacific Center for Theoretical Physics. JG is also supported in part by a TJ Park Science Fellowship of POSCO TJ Park Foundation and the Basic Science Research Program through the National Research Foundation of Korea Research Grant NRF-2016R1D1A1B03930408. GAP is supported by the Fondecyt project 1171811. SS is supported by the Fondecyt 2016 Post-doctoral Grant 3160299. Funding Information: We thank Xingang Chen and Daniel Meerburg for useful discussions and comments. JG is grateful to DFI, FCFM, Universidad de Chile for hospitality while this work was under progress. JG acknowledges the support from the Korea Ministry of Education, Science and Technology, Gyeongsangbuk-Do and Pohang City for Independent Junior Research Publisher Copyright: {\textcopyright} 2017 IOP Publishing Ltd and Sissa Medialab srl.",
year = "2017",
month = may,
day = "8",
doi = "10.1088/1475-7516/2017/05/016",
language = "English",
volume = "2017",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing Ltd.",
number = "5",
}