On the prior dependence of constraints on the tensor-to-scalar ratio

Cortes, Marina, Liddle, Andrew R. and Parkinson, David (2011) On the prior dependence of constraints on the tensor-to-scalar ratio. Journal of Cosmology and Astroparticle Physics, 2011 9: 027.1-027.15. doi:10.1088/1475-7516/2011/09/027

Author Cortes, Marina
Liddle, Andrew R.
Parkinson, David
Title On the prior dependence of constraints on the tensor-to-scalar ratio
Journal name Journal of Cosmology and Astroparticle Physics   Check publisher's open access policy
ISSN 1475-7516
Publication date 2011-09
Sub-type Article (original research)
DOI 10.1088/1475-7516/2011/09/027
Volume 2011
Issue 9
Start page 027.1
End page 027.15
Total pages 15
Place of publication Bristol, United Kingdom
Publisher Institute of Physics Publishing
Collection year 2012
Language eng
Formatted abstract
We investigate the prior dependence of constraints on cosmic tensor perturbations. Commonly imposed is the strong prior of the single-field inflationary consistency equation, relating the tensor spectral index nT to the tensor-to-scalar ratio r. Dropping it leads to significantly different constraints on nT, with both positive and negative values allowed with comparable likelihood, and substantially increases the upper limit on r on scales k = 0.01Mpc−1 to 0.05Mpc−1, by a factor of ten or more. Even if the consistency equation is adopted, a uniform prior on r on one scale does not correspond to a uniform one on another; constraints therefore depend on the pivot scale chosen. We assess the size of this effect and determine the optimal scale for constraining the tensor amplitude, both with and without the consistency relation.
Keyword inflation
alternatives to inflation
primordial gravitational waves (theory)
cosmological parameters from CMBR
Observations Cosmological Interpretation
Inflationary Universe
Extended Inflation
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Article number 027

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2012 Collection
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Citation counts: TR Web of Science Citation Count  Cited 2 times in Thomson Reuters Web of Science Article | Citations
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