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arXiv · 1802.06069

Inflation in a scale invariant universe

Pedro G. Ferreira·Christopher T. Hill·Johannes Noller·Graham G. Ross
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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.

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Pedro G. Ferreira, Christopher T. Hill, Johannes Noller, Graham G. Ross. 2018-02-16. Inflation in a scale invariant universe. https://doi.org/10.1103/physrevd.97.123516

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