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arXiv · 1208.0210

Theoretical bounds on the tensor-to-scalar ratio in the cosmic microwave background

Lotfi Boubekeur
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Abstract

Tensor modes in the cosmic microwave background are one of the most robust signatures of inflation. We derive theoretical bounds on the tensor fraction, as a generalization of the well-known Lyth bound. Under reasonable assumptions, the new bounds are at least two orders of magnitude stronger than the original one. We comment on a previously derived generalization, the so-called Efstathiou-Mack relationship. We also derive a new absolute upper bound on tensors using de Sitter entropy bounds.

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Lotfi Boubekeur. 2013-03-11. Theoretical bounds on the tensor-to-scalar ratio in the cosmic microwave background. https://doi.org/10.1103/physrevd.87.061301

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