In physical cosmology the Quark epoch was
the period in the evolution of the early universe
when the fundamental interactions of gravitation,
electromagnetism, the strong interaction and
the weak interaction had taken their present
forms, but the temperature of the universe
was still too high to allow quarks to bind
together to form hadrons.
The quark epoch began approximately 10−12
seconds after the Big Bang, when the preceding
electroweak epoch ended as the electroweak
interaction separated into the weak interaction
and electromagnetism.
During the quark epoch the universe was filled
with a dense, hot quark–gluon plasma, containing
quarks, leptons and their antiparticles.
Collisions between particles were too energetic
to allow quarks to combine into mesons or
baryons.
The quark epoch ended when the universe was
about 10−6 seconds old, when the average
energy of particle interactions had fallen
below the binding energy of hadrons.
The following period, when quarks became confined
within hadrons, is known as the hadron epoch.
== See also ==
Chronology of the universe
Cosmogony
