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Inflaton field potential producing the exactly flat spectrum of adiabatic perturbations

Alexei A. Starobinsky
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Abstract

Presented is the exact solution of the problem of finding a potential of an inflaton scalar field for which adiabatic perturbations generated during a de Sitter (inflationary) stage in the early Universe have the exactly flat (or, the Harrison-Zeldovich) initial spectrum. This solution lies outside the scope of the slow-roll approximation and higher-order corrections to it. The potential found depends on two arbitrary physical constants, one of those determines an amplitude of perturbations. For small (zero) values of the other constant, a long (infinite) inflationary stage with slow rolling of the inflaton field exists.

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Alexei A. Starobinsky. 2005-07-08. Inflaton field potential producing the exactly flat spectrum of adiabatic perturbations. https://doi.org/10.1134/1.2121807

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