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arXiv · 1306.6518

Cosmological constraints on axionic dark radiation from axion-photon conversion in the early Universe

Tetsutaro Higaki·Kazunori Nakayama·Fuminobu Takahashi
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Abstract

Axions seem ubiquitous in string theories and some of them may be produced non-thermally by heavy scalar decays, contributing to dark radiation. We study various cosmological effects of photons produced from the axionic dark radiation through axion-photon conversion in the presence of primordial magnetic fields, and derive tight constraints on the combination of the axion-photon coupling and the primordial magnetic field.

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Tetsutaro Higaki, Kazunori Nakayama, Fuminobu Takahashi. 2013-08-28. Cosmological constraints on axionic dark radiation from axion-photon conversion in the early Universe. https://doi.org/10.1088/1475-7516%2F2013%2F09%2F030

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