A new constraint on millicharged dark matter from galaxy clusters

• DOI: 10.48550/arxiv.1602.04009
• Publication Date: 2016-01-01
• Authors: Kenji Kadota; Toyokazu Sekiguchi; Hiroyuki Tashiro
• Keywords: High Energy Physics - Phenomenology; Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); 0103 physical sciences; FOS: Physical sciences; General Relativity and Quantum Cosmology (gr-qc); 01 natural sciences; General Relativity and Quantum Cosmology; Astrophysics - Cosmology and Nongalactic Astrophysics

We propose a new constraint on millicharged dark matter from considerations galaxy clusters. The charged moves under the influence of randomly oriented magnetic fields in clusters, and corresponding density profile can significantly differ concordance CDM predictions which are well supported cluster observations. With typical amplitude $B=\mathcal O(1)\,μ$G velocity $v=\mathcal O(100)\,$km/sec at radius $R\simeq 1\,$Mpc, we claim that charge $εe$ ($e$ is elementary charge) with mass $m$ should be bounded as $ε\lesssim 10^{-14}(m/{\rm GeV})$ substantially tighter than other previous constraints.