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arXiv · 2505.20396

Cosmological impact of $ν$DM interactions enhanced in narrow redshift ranges

Sebastian Trojanowski·Lei Zu
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Abstract

The impact of dark matter-neutrino ($ν$DM) interactions on cosmological perturbations has regained attention, spurred by indications of non-zero couplings from high-multipole cosmic microwave background data, weak lensing, and Lyman-$α$ observations. We demonstrate that a similar observational preference is obtained if $ν$DM interactions are primarily enhanced during a specific epoch, $z\sim (10^4-10^5)$, leading to $>3σ$ preference for a non-zero interaction in the combined Atacama Cosmology Telescope and cosmic shear data. This redshift-limited enhancement circumvents other cosmological and astrophysical bounds and can be achieved within a neutrino portal dark matter framework incorporating resonantly enhanced scattering rates.

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Sebastian Trojanowski, Lei Zu. 2025-05-26. Cosmological impact of $ν$DM interactions enhanced in narrow redshift ranges. https://arxiv.org/abs/2505.20396

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