Self-Interacting Dark Matter in Cosmology: accurate numerical implementation and observational constraints

RAFAEL YUNIS; CARLOS ARGUELLES; CLAUDIA G. SCÓCCOLA; DIANA LOPEZ-NACIR; GASTON GIORDANO

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2021

1475-7516

This paper presents a systematic and accurate treatment of the evolution ofcosmological perturbations in self-interacting dark matter models, forparticles which decoupled from the primordial plasma while relativistic. Weprovide a numerical implementation of the Boltzmann hierarchies developed in aprevious paper [JCAP, 09 (2020) 041] in a publicly available Boltzmann code andshow how it can be applied to realistic DM candidates such as sterile neutrinoseither under resonant or non-resonant production mechanisms, and for differentfield mediators. At difference with traditional fluid approximations - alsoknown as a ceff−cvis parametrizations- our approach follows theevolution of phase-space perturbations under elastic DM interactions for a widerange of interaction models, including the effects of late kinetic decoupling.Finally, we analyze the imprints left by different self interacting models onlinear structure formation, which can be constrained using Lyman-αforest and satellite counts. We find new lower bounds on the particle mass thatare less restrictive than previous constraints.