Abstract
The swampland de Sitter conjecture in combination with upper limits on the tensor-to-scalar ratio derived from observations of the cosmic microwave background endangers the paradigm of slow-roll single-field inflation. This conjecture constrains the first and the second derivatives of the inflationary potential in terms of two constants and . In view of these restrictions, we reexamine single-field inflationary potentials with -duality symmetry, which ameliorate the unlikeliness problem of the initial condition. We compute at next-to-leading order in slow-roll parameters for the most general form of -dual potentials and confront model predictions to constraints imposed by the de Sitter conjecture. We find that and can accommodate the 95% C.L. upper limit on . By imposing at least -folds of inflation with the effective field theory description valid only over a field displacement when measured as a distance in the target space geometry, we further restrict , while the constraint on remains unchanged. We comment on how to accommodate the required small values of and .
- Received 25 March 2021
- Accepted 3 June 2021
DOI:https://doi.org/10.1103/PhysRevD.103.123537
Published by the American Physical Society under the terms of the 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. Funded by SCOAP3.
Published by the American Physical Society