Original title: How much chaos can be generated by gravitational collapse before reaching the Planck scale?
David Brizuela, Sara F. Uria, Edward Wilson-Ewing · September 2026
General relativity suggests that gravity becomes wildly chaotic near a singularity, a point where gravity turns infinitely strong. However, general relativity breaks down there, and quantum gravity should take over near tiny limits called the Planck scaleThe extremely small scale where quantum gravity effects become important, about 10^-35 meters.. Researchers wanted to know how much chaos actually builds up during a gravitational collapse before reaching this boundary, while ordinary physics still works. They tracked the collapse from a strong classical setting down to the Planck scale. They measured the disorder using mathematical tools that track randomness and wave patterns, called Shannon entropyA measure of how much disorder or uncertainty is in a system., Kullback-Leibler divergenceA way to measure how different two probability distributions are., and Fourier analysis. They discovered that chaos remains relatively underdeveloped by the time collapse hits the Planck scale. This means the chaotic motion is not strong enough to wipe out all information about the starting state of the universe, or about an earlier universe in models where the cosmos bounces.
You are trying to fold a crumpled map back into a perfect rectangle. Normally, as you smooth it out, the creases become predictable. But if the map gets small enough, the folds become chaotic and impossible to follow. Here, the map is the universe collapsing, and the creases are the gravitational fluctuations. The researchers measured how messy the map gets right before it becomes too small to handle, and found it is still surprisingly neat.
If the chaos is weak, the universe's initial conditions might survive a collapse and carry over into a new cosmic bounce. That means information about the past is not completely lost inside a singularity. It also shows exactly where classical physics stops being reliable before quantum gravity takes over.
This work only studies classical general relativity up to the Planck scale, ignoring quantum gravity. It does not model realistic matter distributions or full numerical simulations. The results are based on a specific anisotropic model (Bianchi IX), so applicability to generic collapses is uncertain.
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How much chaos can be generated by gravitational collapse before reaching the Planck scale? — David Brizuela, Sara F. Uria, Edward Wilson-Ewing
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.