Friction from dark matter got so hot in the early universe that it actually stopped the very first stars from being born.
March 23, 2026
Original Paper
Impact of subhalo dynamical friction heating on the formation of the first structures in the universe
arXiv · 2603.19385
The Takeaway
Dark matter is usually thought of as a cold, ghostly substance, but this study shows its gravitational pull can churn gas into a 'fever' that prevents it from cooling into stars. This friction effectively changed the birth conditions of the entire universe.
From the abstract
We present a model for gas heating, driven by dynamical friction from orbiting subhalos within dark matter halos. Using data from the TNG50 simulation, we derive the subhalo mass function and calculate the dynamical friction heating rate for a wide range of halo masses and redshifts from $z = 15$ to 0. Our results show that, by converting gravitational potential energy into thermal energy, dynamical friction is an important mechanism for galaxy quenching in massive halos at low redshifts, consis