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lepton era comparison table

Subject	has start time	has definition	is preceded by	is followed by	is a kind of	has duration	has temperature
Big Bang era	relative to the Big Bang	A theoretical era postulated to have occurred after the Big Bang. They are in order : Planck era hadron era inflation era lepton era nucleosynthetic era radiation era matter era			era
lepton era	10-5 s after Big Bang	The Big Bang era when the temperature had dropped to about 1012 K and when the Universe consisted mainly of leptons and photons. It lasted until the temperature fell below 1010 K. At this stage, the characteristic photon energy fell below the rest mass energy of an electron, and the abundance of electron-positron pairs fell by many orders of magnitude. Only one electron survived for every 108 photons. The universe was subsequently radiation-dominated (substantial numbers of neutrinos were also present, but they did not interact directly with the matter or the radiation).	hadron era	nucleosynthetic era	Big Bang era	1 s	1010 K to 1012 K

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