Optimal bispectrum constraints on single-field models of inflation

Anderson, Gemma J, Regan, Donough and Seery, David (2014) Optimal bispectrum constraints on single-field models of inflation. Journal of Cosmology and Astroparticle Physics, 2014 (7). 017. ISSN 1475-7516

[img]
Preview
PDF - Submitted Version
Download (2MB) | Preview

Abstract

We use WMAP 9-year bispectrum data to constrain the free parameters of an 'effective field theory' describing fluctuations in single-field inflation. The Lagrangian of the theory contains a finite number of operators associated with unknown mass scales. Each operator produces a fixed bispectrum shape, which we decompose into partial waves in order to construct a likelihood function. Based on this likelihood we are able to constrain four linearly independent combinations of the mass scales. As an example of our framework we specialize our results to the case of 'Dirac-Born-Infeld' and 'ghost' inflation and obtain the posterior probability for each model, which in Bayesian schemes is a useful tool for model comparison. Our results suggest that DBI-like models with two or more free parameters are disfavoured by the data by comparison with single parameter models in the same class.

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: David Seery
Date Deposited: 08 Sep 2014 09:18
Last Modified: 06 Mar 2017 10:50
URI: http://sro.sussex.ac.uk/id/eprint/49757

View download statistics for this item

📧 Request an update