"Titanic Galaxy Cluster Collision Challenges Cosmology Theories"

The collision of two massive galaxy clusters, including El Gordo, challenges the predictions of the Lambda-cold dark matter (ΛCDM) cosmological model, which suggests that galaxy clusters should take a long time to form. The collision occurred when the Universe was only half its current age, defying the standard theory of cosmology. The study, published in the Astrophysical Journal, used updated estimates of El Gordo's mass and simulations to analyze the collision, revealing a severe tension with ΛCDM for any plausible collision velocity. This collision, along with other examples, suggests that structure formation in the Universe may have occurred faster than expected in ΛCDM.