Disappearing inflaton potential via heavy field dynamics

Journal Article · Mon Feb 01 04:00:00 EST 2016 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2016/02/041· OSTI ID:22524996

Kitajima, Naoya; Takahashi, Fuminobu ^[1]

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1. Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

We propose a possibility that the inflaton potential is significantly modified after inflation due to heavy field dynamics. During inflation such a heavy scalar field may be stabilized at a value deviated from the low-energy minimum. In extreme cases, the inflaton potential vanishes and the inflaton becomes almost massless at some time after inflation. Such transition of the inflaton potential has interesting implications for primordial density perturbations, reheating, creation of unwanted relics, dark radiation, and experimental search for light degrees of freedom. To be concrete, we consider a chaotic inflation in supergravity where the inflaton mass parameter is promoted to a modulus field, finding that the inflaton becomes stable after the transition and contributes to dark matter. Another example is a hilltop inflation (also called new inflation) by the MSSM Higgs field which acquires a large expectation value just after inflation, but it returns to the origin after the transition and finally rolls down to the electroweak vacuum. Interestingly, the smallness of the electroweak scale compared to the Planck scale is directly related to the flatness of the inflaton potential.

• OSTI ID: 22524996
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 02 Vol. 2016; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CHAOS THEORY
COMPARATIVE EVALUATIONS
COSMOLOGICAL INFLATION
DEGREES OF FREEDOM
DENSITY
DISTURBANCES
EXPECTATION VALUE
HIGGS BOSONS
HIGGS MODEL
INFLATIONARY UNIVERSE
INFLATONS
MASS
NONLUMINOUS MATTER
POTENTIALS
SCALAR FIELDS
SUPERGRAVITY
VISIBLE RADIATION