English

Multi-field Inflation in High-Slope Potentials

High Energy Physics - Theory 2020-04-29 v4 Cosmology and Nongalactic Astrophysics

Abstract

We present two families of multi-field potentials that support inflation while satisfying the refined de Sitter and the distance swampland conjectures. Both families feature Planck-compatible phenomenology. The first is a helix-type potential, in a flat field-space metric, that satisfies the conjectures via a high turning rate. This model has a tensor-toscalar ratio close to, but below, the current experimental limits and small non-gaussianities. The second family, an example of orbital inflation, utilizes a negatively curved field metric to achieve prolonged inflation with nontrivial turning in the presence of a tachyonic direction. Although perturbations in this model undergo an exponential growth before horizon exit, it is always possible to match the measured amplitude of the power spectrum by lowering the scale of inflation if the turning rate is low enough. We identify a Planck-compatible region of parameter space in which the scale of inflation is above that of nucleosynthesis. Due to the rapid growth, this model predicts an exponentially suppressed value for the tensor-to-scalar ratio.

Keywords

Cite

@article{arxiv.1905.07495,
  title  = {Multi-field Inflation in High-Slope Potentials},
  author = {Vikas Aragam and Sonia Paban and Robert Rosati},
  journal= {arXiv preprint arXiv:1905.07495},
  year   = {2020}
}

Comments

34 pages, 10 figures. v2: updated section 4 and appendix B to properly give credit to previous work. v3: fix geodesic prefactor in appendix C. v4: include new analysis of both potentials, matches version accepted for publication in JCAP

R2 v1 2026-06-23T09:11:19.434Z