TY - JOUR

T1 - Small field models of inflation that predict a tensor-to-scalar ratio r=0.03

AU - Wolfson, Ira

AU - Brustein, Ram

N1 - Funding Information:
The research of R. B. and I. W. was supported by the Israel Science Foundation Grant No. 1294/16. I. W. would like to acknowledge Ido Ben-Dayan for useful discussions regarding the swampland conjecture and its cosmological implications.
Publisher Copyright:
© 2019 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/" Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

PY - 2019/8/13

Y1 - 2019/8/13

N2 - Future observations of the cosmic microwave background polarization are expected to set an improved upper bound on the tensor-to-scalar ratio of r0.03. Recently, we showed that small field models of inflation can produce a significant primordial gravitational wave signal. We constructed viable small field models that predict a value of r as high as 0.01. Models that predict higher values of r are more tightly constrained and lead to larger field excursions. This leads to an increase in tuning of the potential parameters and requires higher levels of error control in the numerical analysis. Here, we present viable small field models which predict r=0.03. We further find the most likely candidate among these models which fit the most recent Planck data while predicting r=0.03. We thus demonstrate that this class of small field models is an alternative to the class of large field models. The BICEP3 experiment and the Euclid and SPHEREx missions are expected to provide experimental evidence to support or refute our predictions.

AB - Future observations of the cosmic microwave background polarization are expected to set an improved upper bound on the tensor-to-scalar ratio of r0.03. Recently, we showed that small field models of inflation can produce a significant primordial gravitational wave signal. We constructed viable small field models that predict a value of r as high as 0.01. Models that predict higher values of r are more tightly constrained and lead to larger field excursions. This leads to an increase in tuning of the potential parameters and requires higher levels of error control in the numerical analysis. Here, we present viable small field models which predict r=0.03. We further find the most likely candidate among these models which fit the most recent Planck data while predicting r=0.03. We thus demonstrate that this class of small field models is an alternative to the class of large field models. The BICEP3 experiment and the Euclid and SPHEREx missions are expected to provide experimental evidence to support or refute our predictions.

UR - http://www.scopus.com/inward/record.url?scp=85072223077&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.100.043522

DO - 10.1103/PhysRevD.100.043522

M3 - Article

AN - SCOPUS:85072223077

SN - 1550-7998

VL - 100

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

IS - 4

M1 - 043522

ER -