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arXiv · 2610.40766

Hints of self-interacting dark matter from strong gravitational lensing

Daniel Gilman·Kalliopi Petraki·Thomas Pignard·James Gurian·Alex Kusenko·Anna Nierenberg
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Abstract

An analysis of 29 quadruply imaged quasars hints at dark matter halo densities consistent with gravothermal core collapse, a key prediction of self-interacting dark matter. We interpret this evidence through elastic Yukawa scattering, combining lensing with upper limits on the cross-section strength from galaxy clusters and Milky Way satellite evaporation. Favored models have dark matter masses of $20$-$80\,{\rm GeV}$, MeV-scale mediators, and Yukawa-potential strengths near $10^{-3}$, yielding cross-sections of $10^2$--$10^4 \, {\rm cm^2\,g^{-1}}$ at $10\,{\rm km\,s^{-1}}$. Cosmological, direct and indirect detection bounds on MeV-scale mediators motivate a neutrinophilic scalar dilepton that decays invisibly without Higgs mixing. These results demonstrate how inferences on core collapse constrain dark sector physics.

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Daniel Gilman, Kalliopi Petraki, Thomas Pignard, James Gurian, Alex Kusenko, Anna Nierenberg. 2026-10-29. Hints of self-interacting dark matter from strong gravitational lensing. https://arxiv.org/abs/2610.40766

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