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DOE OSTI · 21550314

Ultraviolet-Protected Inflation

Germani, Cristiano·Kehagias, Alex
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Abstract

In natural inflation, the inflaton is a pseudo-Nambu-Goldstone boson which acquires a mass by explicit breaking of a global shift symmetry at scale f. In this case, for small field values, the potential is flat and stable under radiative corrections. Nevertheless, slow roll conditions enforce f>>M{sub p}, making the validity of the whole scenario questionable. In this Letter, we show that a coupling of the inflaton kinetic term to the Einstein tensor allows f<<M{sub p} by enhancing the gravitational friction acting on the inflaton during inflation. This new unique interaction (a) keeps the theory perturbative in the whole inflationary trajectory, (b) preserves the tree-level shift invariance of the pseudo-Nambu-Goldstone boson, and (c) avoids the introduction of any new degrees of freedom with respect to standard natural inflation.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSBOSONSCORRECTIONSCOUPLINGDEGREES OF FREEDOMELECTROMAGNETIC RADIATIONELEMENTARY PARTICLESFRICTIONGOLDSTONE BOSONSINTERACTIONSMASSPOSTULATED PARTICLESPOTENTIALSRADIATIONSRADIATIVE CORRECTIONSSYMMETRYTENSORSTRAJECTORIESULTRAVIOLET RADIATION

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Germani, Cristiano, Kehagias, Alex. 2011-04-22. Ultraviolet-Protected Inflation. https://doi.org/10.1103/physrevlett.106.161302

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