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arXiv · 2407.18252

From 100 kpc to 10 Gpc: Dark Matter self-interactions before and after DESI

Salvatore Bottaro·Emanuele Castorina·Marco Costa·Diego Redigolo·Ennio Salvioni
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Abstract

We consider Dark Matter self-interactions mediated by ultralight scalars. We show that effectively massless mediators lead to an enhancement of the matter power spectrum, while heavier mediators lead to a suppression, together with a feature around their Jeans scale. We derive the strongest present constraints by combining Planck and BOSS data. The recent DESI measurements of Baryon Acoustic Oscillations exhibit a mild $2\sigma$ preference for long-range self-interactions, as strong as $4$ per mille of the gravitational coupling. Full-shape analyses of forthcoming DESI and Euclid data will confirm or disprove such a hint.

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Salvatore Bottaro, Emanuele Castorina, Marco Costa, Diego Redigolo, Ennio Salvioni. 2024-07-25. From 100 kpc to 10 Gpc: Dark Matter self-interactions before and after DESI. https://doi.org/10.1103/gc78-96l5

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