English

Inflation in a scale invariant universe

Cosmology and Nongalactic Astrophysics 2018-06-26 v2 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

A scale-invariant universe can have a period of accelerated expansion at early times: inflation. We use a frame-invariant approach to calculate inflationary observables in a scale invariant theory of gravity involving two scalar fields - the spectral indices, the tensor to scalar ratio, the level of isocurvature modes and non-Gaussianity. We show that scale symmetry leads to an exact cancellation of isocurvature modes and that, in the scale-symmetry broken phase, this theory is well described by a single scalar field theory. We find the predictions of this theory strongly compatible with current observations.

Keywords

Cite

@article{arxiv.1802.06069,
  title  = {Inflation in a scale invariant universe},
  author = {Pedro G. Ferreira and Christopher T. Hill and Johannes Noller and Graham G. Ross},
  journal= {arXiv preprint arXiv:1802.06069},
  year   = {2018}
}

Comments

9 pages, 2 figures; v2: minor clarifications added, matches published version

R2 v1 2026-06-23T00:24:54.161Z