Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/144887
Title: Thermalized axion inflation: Natural and monomial inflation with small r
Author: Ferreira, Ricardo Z.
Notari, Alessio
Keywords: Cosmologia
Gravitació
Cosmology
Gravitation
Issue Date: 29-Mar-2018
Publisher: American Physical Society
Abstract: A safe way to reheat the Universe, in models of natural and quadratic inflation, is through shift symmetric couplings between the inflaton ϕ and the Standard Model (SM), since they do not generate loop corrections to the potential V ( ϕ ) . We consider such a coupling to SM gauge fields, of the form ϕ F F / f , with sub-Planckian f . In this case, gauge fields can be exponentially produced already during inflation and thermalize via interactions with charged particles, as pointed out in previous work. This can lead to a plasma of temperature T during inflation, and the thermal masses g T of the gauge bosons can equilibrate the system. In addition, inflaton perturbations δ ϕ can also have a thermal spectrum if they have sufficiently large cross sections with the plasma. In this case, inflationary predictions are strongly modified: (1) scalar perturbations are thermal, and so enhanced over the vacuum, leading to a generic way to suppress the tensor-to-scalar ratio r ; (2) the spectral index is n s − 1 = η − 4 ε . After presenting the relevant conditions for thermalization, we show that thermalized natural and monomial models of inflation agree with present observations and have r ≈ 10 − 3 − 10 − 2 , which is within reach of next generation CMB experiments.
Note: Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.97.063528
It is part of: Physical Review D, 2018, vol. 97, num. 6, p. 063528
URI: http://hdl.handle.net/2445/144887
Related resource: https://doi.org/10.1103/PhysRevD.97.063528
ISSN: 2470-0010
Appears in Collections:Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB))
Articles publicats en revistes (Física Quàntica i Astrofísica)

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