# rmx-s-astrophys: even darker than once thought

<< Astronomers (..) have studied how dark matter in clusters of galaxies behaves when the clusters collide. >>

<< (..) dark matter interacts with itself even less than previously thought >>

http://www.spacetelescope.org/news/heic1506/

David Harvey, Richard Massey, et al. The nongravitational interactions of dark matter in colliding galaxy clusters. Science, 27 March 2015: 1462-1465

http://dx.doi.org/10.1126/science.1261381