Steps to reconcile inflationary tensor and scalar spectra

Vinícius Miranda, Wayne Hu, Peter Adshead

Research output: Contribution to journalArticlepeer-review


The recent BICEP2 B-mode polarization determination of an inflationary tensor-scalar ratio r=0.2-0.05+0.07 is in tension with simple scale-free models of inflation due to a lack of a corresponding low multipole excess in the temperature power spectrum which places a limit of r0.002<0.11 (95% C.L.) on such models. Single-field inflationary models that reconcile these two observations, even those where the tilt runs substantially, introduce a scale into the scalar power spectrum. To cancel the tensor excess, and simultaneously remove the excess already present without tensors, ideally the model should introduce this scale as a relatively sharp transition in the tensor-scalar ratio around the horizon at recombination. We consider models which generate such a step in this quantity and find that they can improve the joint fit to the temperature and polarization data by up to 2ΔlnL≈-14 without changing cosmological parameters. Precision E-mode polarization measurements should be able to test this explanation.

Original languageEnglish (US)
Article number101302
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number10
StatePublished - May 22 2014

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'Steps to reconcile inflationary tensor and scalar spectra'. Together they form a unique fingerprint.

Cite this