 Flatness problem

In a decelerating expanding universe, $|\Omega -1|$ grows, so its small present value requires extremely fine-tuned early initial data unless an earlier mechanism drives $\Omega$ toward one.

The Flatness Problem is a cosmological issue that arises in the context of the Big Bang model of the universe. It pertains to the observed geometry of the universe and the specific conditions necessary for it to be flat. ### Key Points: 1. **Cosmological Parameters**: - The density of the universe, represented as \( \Omega \), compares the actual density (matter and energy) to the critical density needed for a flat universe.