QCD axion window and low-scale inflation
By F. Takahashi, W. Yin, A. Guth. Physical Review D, 2018
140 citations recorded by the source corpus.
We show that the upper bound of the classical QCD axion window can be significantly relaxed for low-scale inflation. If the Gibbons-Hawking temperature during inflation is lower than the QCD scale, the initial QCD axion misalignment angle follows the Bunch-Davies distribution. The distribution is peaked at the strong $CP$ conserving minimum if there is no other light degree of freedom contributing to the strong $CP$ phase. As a result, the axion overproduction problem is significantly relaxed even for an axion decay constant larger than $1{0}^{12}\text{ }\text{ }\mathrm{GeV}$. We also provide concrete hilltop inflation models where the Hubble parameter during inflation is comparable to or much smaller than the QCD scale, with successful reheating taking place via perturbative decays or dissipation processes.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/62fa4183c3da7379dd4babecb04ce323101293fb
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In Astronomy and Astrophysics
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- Igor G. Irastorza
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- G. Ghisellini
- F. Tavecchio
- Marek Lewicki
- John Ellis
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In Nuclear and High Energy Physics
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- Maurizio Giannotti
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Citations in the corpus
- AION: an atom interferometer observatory and network (2019, background): “, through the misalignment mechanism [31–33] or quantum fluctuations during inflation [34–36], and such DM bosons are naturally cold, as required by the standard cosmological paradigm for astrophysical structure formation.”
- Physics potential of the International Axion Observatory (IAXO) (2019, background): “around and showed that the quantum fluctuations during a low-HI period of inflation may also be responsible for generating a large enough misalignment angle to give rise to QCD axion or ALP DM [108, 109].”
- The landscape of QCD axion models (2020, background): “without any fine tuning, in low-scale inflation models in which inflation lasts sufficiently long [275, 276].”