Hints of dark matter-neutrino interactions in Lyman-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>α</mml:mi></mml:math> data
Deanna C. Hooper, Matteo Lucca
Abstract
In this work we investigate the possibility that dark matter and (massive) neutrinos can interact via a simple, constant cross section. Building on previous numerical efforts, we constrain this model with Cosmic Microwave Background, Baryon Acoustic Oscillations, and, in particular, Lyman-$\ensuremath{\alpha}$ data. We find that the latter hint to a significant departure from $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$, with a preference for an interaction strength about $3\ensuremath{\sigma}$ away from zero. We trace the origin of this preference back to the additional tilt that the interacting scenario can imprint on the Lyman-$\ensuremath{\alpha}$ flux power spectrum, solving a well-known tension in the determination of this quantity between early-time and Lyman-$\ensuremath{\alpha}$ probes. Future work including complementary Lyman-$\ensuremath{\alpha}$ data as well as dedicated numerical simulations will be crucial in order to test these results.