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arXiv · 1711.07344

A novel way to determine the scale of inflation

Kari Enqvist·Robert J. Hardwick·Tommi Tenkanen·Vincent Vennin·David Wands
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Abstract

We show that in the Feebly Interacting Massive Particle (FIMP) model of Dark Matter (DM), one may express the inflationary energy scale $H_*$ as a function of three otherwise unrelated quantities, the DM isocurvature perturbation amplitude, its mass and its self-coupling constant, independently of the tensor-to-scalar ratio. The FIMP model assumes that there exists a real scalar particle that alone constitutes the DM content of the Universe and couples to the Standard Model via a Higgs portal. We consider carefully the various astrophysical, cosmological and model constraints, accounting also for variations in inflationary dynamics and the reheating history, to derive a robust estimate for $H_*$ that is confined to a relatively narrow range. We point out that, within the context of the FIMP DM model, one may thus determine $H_*$ reliably even in the absence of observable tensor perturbations.

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Kari Enqvist, Robert J. Hardwick, Tommi Tenkanen, Vincent Vennin, David Wands. 2018-02-02. A novel way to determine the scale of inflation. https://doi.org/10.1088/1475-7516%2F2018%2F02%2F006

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