What are the stages in the life of a universe? Geological periods describe varying phases in the last few hundred million years on earth.
Are there any names for the periods on a timescale 1-2 orders of magnitude greater, that is, for the stages of a/the universe?
I found some bits and pieces of information but nothing as clear as I did for geological periods, possibly because of the conjecture involved.
Yes there are. They are mainly based on what dominates the energy density of the universe at the time and they are known as epochs.
Thus we have the inflationary epoch in the first tiny fraction ($\sim 10^{-32}$) of a second, when the energy density was dominated by an inflationary field.
Then we are in the electroweak epoch, when the weak nuclear and electromagnetic forces were united.
This is followed by the quark epoch when the electromagnetic and weak nuclear forces separate at about $10^{-12}$s, which is followed by the hadron epoch between about a millionth of a second and 1 second, when quarks were able to be confined into multi-quark hadrons.
Then the lepton epoch between about 1 second and a minute when most of the hadrons have annihilated with each other and the energy density is dominated by electrons, positrons and neutrinos, although this also coincides with the &quot;epoch of primordial nucleosynthesis&quot; when the first multi-nucleon nuclei were built.
From there until about 300,000 years, we have the radiation epoch, when photons dominated the energy density of the universe.
After that, the universe entered the matter-dominated epoch for about 5 billion years and now we are in the epoch where the universe is dominated by dark energy.
There are other schemes and other nomenclatures depending on what physics is being focused on. For example, people interested in the formation of the first stars will talk about the &quot;epoch of reionization&quot;, which occurred some 100 million years after the big-bang. Those studying the cosmic microwave background talk about the &quot;epoch of recombination&quot;, which coincides roughly with the transition from a radiation to a matter-dominated universe.