Collisionless shocks in self-interacting dark matter
Abstract
Self-interacting dark matter has been proposed as a solution to small scale problems in cosmological structure formation, and hints of dark matter self scattering have been observed in mergers of galaxy clusters. One of the simplest models for self-interacting dark matter is a particle that is charged under dark electromagnetism, a new gauge interaction analogous to the usual electromagnetic force, but operating on the dark matter particle instead of the visible particles. In this case, the collisional behaviour of dark matter is primarily due to the formation of collisionless shocks, that should affect the distribution of DM in merging galaxy clusters. We evaluate the time and length scales of shock formation in cluster mergers, and discuss the implications for modelling charged dark matter in cosmological simulations.
Cite
@article{arxiv.1707.03662,
title = {Collisionless shocks in self-interacting dark matter},
author = {Matti Heikinheimo and Martti Raidal and Christian Spethmann and Hardi Veermae},
journal= {arXiv preprint arXiv:1707.03662},
year = {2017}
}
Comments
6 pages + references, based on a talk at EPS plasma physics conference, June 26-30, 2017