News from 'El Gordo': Study suggests dark matter may have collisional properties after all

Contrary to what is established by the standard model, dark matter may indeed be self-interacting. This was the conclusion of a piece of research published in Astronomy & Astrophysics and conducted by Riccardo Valdarnini of SISSA's Astrophysics and Cosmology group. Using numerical simulations, the study analyzed what happens inside "El Gordo" (literally "The Fat One" in Spanish), a giant cluster merger seven billion light years away from us.