Other epochs such as the grand unification epoch follow afterwards.

The grand unification epoch ended at approximately 10 seconds after the Big Bang.

During the grand unification epoch, physical characteristics such as mass, charge, flavour and colour charge were meaningless.

The rapid expansion of space meant that elementary particles remaining from the grand unification epoch were now distributed very thinly across the universe.

The grand unification epoch begins when gravitation separates from the other forces of nature, which are collectively known as gauge forces.

The grand unification epoch ends when the GUT forces further separate into the strong and electroweak forces.

The inflationary epoch comprises the first part of the electroweak epoch following the grand unification epoch.

The expansion is thought to have been triggered by the phase transition that marked the end of the preceding grand unification epoch at approximately 10 seconds after the Big Bang.

However, shortly thereafter, during the grand unification epoch (10 seconds after the Big Bang) gravity began to separate from the other three forces of electromagnetism, the strong, and weak nuclear force.

In modern inflationary cosmology, the traditional grand unification epoch, like the Planck epoch, does not exist, though similar conditions likely would have existed in the universe prior to inflation.

Modern cosmology now suggests that the Planck epoch may have inaugurated a period of unification, known as the grand unification epoch, and that symmetry breaking then quickly led to the era of cosmic inflation, the Inflationary epoch, during which the universe greatly expanded in scale over a very short period of time.