Ultradiffuse galaxies (UDGs) such as NGC 1052-DF2 and DF4 exhibit critically low dark matter content, challenging the standard LambdaCDM paradigm. We propose that in the early Universe (z > 10), differential spins of primordial gas clouds drove high-velocity collisions. Opposing spins channel shock compression within dense filaments; rapid radiative cooling reduces post-shock temperatures from ~10⁵ K to 10²-10⁴ K, enabling collapse and triggering star formation bursts independent of dark matter halos. This channel is transient: cosmic expansion reduces gas density, suppressing collisions at lower redshifts. We predict a population of young, turbulent, dark-matter-free starbursts at z > 10 detectable by JWST, which rapidly disperse due to feedback. This model reconciles dark-matter-deficient observables with LambdaCDM through baryon-dominated dynamics during Cosmic Dawn.
Stanislav Vasilyev (Fri,) studied this question.