Big Rip
The truth of the hypothesis relies on the type of dark energy present in our universe. The type that could prove this hypothesis is a constantly increasing form of dark energy, known as phantom energy. If the dark energy in the universe increases without limit, it could destroy all forces that hold the universe together. The key value is the equation of state parameter w, the ratio between the dark energy pressure and its energy density. If -1 < w < 0, the expansion of the universe continues to increase, but the dark energy tends to stop over time. So the Big Rip does not happen. Phantom energy has w < −1, which means that its density increases as the universe expands.