Alternatively , it was the time when the time scale for weak interactions became greater than the age of the universe at that time .
Decoupling occurred approximately at the time when the rate of those weak interactions was slower than the rate of expansion of the universe .
It was the time when the time scale for weak interactions became greater than the age of the universe at that time .
Decoupling occurred approximately at the time when the rate of those weak interactions was slower than the rate of expansion of the universe .