Scale-dependent non-Gaussianity and the CMB power asymmetry

Byrnes, Christian T and Tarrant, Ewan R M (2015) Scale-dependent non-Gaussianity and the CMB power asymmetry. Journal of Cosmology and Astroparticle Physics, 2015 (07). 007-007. ISSN 1475-7516

[img] PDF - Accepted Version
Download (598kB)

Abstract

We introduce an alternative parametrisation for the scale dependence of the non–linearity parameter fNL in quasi-local models of non–Gaussianity. Our parametrisation remains valid when fNL changes sign, unlike the commonly adopted power law ansatz fNL(k) ∝ knfNL. We motivate our alternative parametrisation by appealing to the self-interacting curvaton scenario, and as an application, we apply it to the CMB power asymmetry. Explaining the power asymmetry requires a strongly scale dependent non-Gaussianity. We show that regimes of model parameter space where fNL is strongly scale dependent are typically associated with a large gNL and quadrupolar power asymmetry, which can be ruled out by existing observational constraints.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QB Astronomy > QB0980 Cosmogony. Cosmology
Depositing User: Christian Byrnes
Date Deposited: 15 Jul 2016 15:11
Last Modified: 07 Mar 2017 08:16
URI: http://sro.sussex.ac.uk/id/eprint/62028

View download statistics for this item

📧 Request an update