On the prior dependence of constraints on the tensor-to-scalar ratio
- Berkeley Lab, Berkeley, CA 94720 (United States)
- Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom)
- School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia)
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 n{sub T} to the tensor-to-scalar ratio r. Dropping it leads to significantly different constraints on n{sub T}, with both positive and negative values allowed with comparable likelihood, and substantially increases the upper limit on r on scales k = 0.01 Mpc{sup -1} to 0.05 Mpc{sup -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.
- OSTI ID:
- 22277732
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2011, Issue 09; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
CONSTRAINTS ON SCALAR AND TENSOR PERTURBATIONS IN PHENOMENOLOGICAL AND TWO-FIELD INFLATION MODELS: BAYESIAN EVIDENCES FOR PRIMORDIAL ISOCURVATURE AND TENSOR MODES
Planck 2015 results: XX. Constraints on inflation