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arXiv · 1405.7969

A Universal Bound on Excitations of Heavy Fields during Inflation

Thorsten Battefeld·R. C. Freitas
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Abstract

We discuss a universal bound on any excitation of heavy fields during inflation: the ratio of the heavy field's energy density to the one driving inflation must be less than the maximally allowed relative amplitude of oscillations in the power-spectrum (less than one percent according to PLANCK). This bound can be traced back to the sudden change of the equation of state parameter across the excitation event. We employ a sudden transition approximation at the perturbed level, which has been used before in different settings; we check its validity by comparison to the full multi-field result in a concrete case study involving a sudden mass change of an inflaton.

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Thorsten Battefeld, R. C. Freitas. 2014-06-13. A Universal Bound on Excitations of Heavy Fields during Inflation. https://doi.org/10.1088/1475-7516%2F2014%2F09%2F029

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