A massive blow for $\Lambda$CDM $-$ the high redshift, mass, and collision velocity of the interacting galaxy cluster El Gordo contradicts concordance cosmology

E. Asencio, I. Banik, P. Kroupa

El Gordo (ACT-CL J0102-4915) is an extremely massive galaxy cluster ($M_{200}\approx 3\times 10^{15}$ $M_{\odot }$) at redshift $z=0.87$ composed of two subclusters with mass r…