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arXiv · 2607.01399

Secondary Production of Photons from ALP Dark Matter interacting with a Cosmological Magnetic Field

Abdias Aires·Robert Brandenberger·Ashu Kushwaha
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Abstract

Under the assumption that dark matter is a coherently oscillating pseudoscalar field coupled to electromagnetism by the usual Chern-Simons term, we study the production of secondary photons from dark matter fluctuations coupled to a pre-existing magnetic field, taking into account the spectral distribution of the magnetic field. Specifically, we apply the formalism to the case of a large-scale magnetic field generated previously via a parametric resonance instability due to the same Chern-Simons coupling. However, our analysis is applicable to any spectrum of cosmological scale magnetic field fluctuations present at the time of recombination. We show that obtaining a sufficiently large flux of photons in the Lyman-Werner frequency range is consistent with constraints from CMB and X-ray observations.

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Abdias Aires, Robert Brandenberger, Ashu Kushwaha. 2026-07-01. Secondary Production of Photons from ALP Dark Matter interacting with a Cosmological Magnetic Field. https://arxiv.org/abs/2607.01399

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