A 'runaway demolition derby' of colliding stars in the early universe may explain the mystery of how massive galaxies formed so quickly after the Big Bang.
March 31, 2026
Original Paper
A cosmological framework for stellar collisions at high redshift in proto-globular clusters, nuclear star clusters, and Little Red Dots
arXiv · 2603.26872
The Takeaway
Instead of growing slowly by pulling in gas, stars in the dense environments of the early universe likely grew by smashing into each other in head-on collisions. This runaway effect creates massive stars and gas clouds rapidly enough to explain the 'impossible' galaxies recently spotted by the James Webb Space Telescope.
From the abstract
Observations and cosmological simulations indicate that the early Universe hosted numerous compact, high-density stellar systems, where close encounters and physical collisions between stars were likely common. We develop a bottom-up framework for stellar dynamics in such environments, spanning systems with and without intermediate- and supermassive black holes, and covering regimes where stellar collisions may or may not dominate the evolution. This radially-resolved analytic model connects den