Space begins expanding. 10 -43 seconds. The Planck time . We do not know what happened before this time, because our knowledge of physics breaks down at this point. At the Planck time, symmetry breaks.
Gravity becomes a distinct force.
We have entered the GUT era . 10 -35 seconds . The electro-weak and the strong nuclear forces become distinct. 10 -32 seconds . The inflation smooths out all irregularities, ensuring that the entire visible universe was in causal contact, and makes the geometry of the universe flat.