Full-shape BOSS constraints on dark matter interacting with dark radiation and lifting the S8 tension

Henrique Rubira, Asmaa Mazoun, Mathias Garny

Submitted on 8 September 2022


In this work we derive constraints on interacting dark matter-dark radiation models from a full-shape analysis of BOSS-DR12 galaxy clustering data, combined with Planck legacy cosmic microwave background (CMB) and baryon acoustic oscillation (BAO) measurements. We consider a set of models parameterized within the effective theory of structure formation (ETHOS), quantifying the lifting of the S8 tension in view of KiDS weak-lensing results. The most favorable scenarios point to a fraction f10100% of interacting dark matter as well as a dark radiation temperature that is smaller by a factor ξ0.10.15 compared to the CMB, leading to a reduction of the tension to the 1σ level. The temperature dependence of the interaction rate favored by relaxing the S8 tension is realized for a weakly coupled unbroken non-Abelian SU(N) gauge interaction in the dark sector. To map our results onto this SU(N) model, we compute higher-order corrections due to Debye screening. We find a lower bound αdgd2/(4π)108(109) for dark matter mass 1000(1) GeV for relaxing the S8 tension, consistent with upper bounds from galaxy ellipticities and compatible with self-interactions relevant for small-scale structure formation.


Comment: 38 pages, 8 figures, 1 ancillary figure

Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics; High Energy Physics - Phenomenology