Approximately how long after the Big Bang did matter's density surpass that of radiation, initiating the matter-dominated era?

Answer

47,000 years

Around 47,000 years after the Big Bang, the energy density of matter exceeded that of radiation because radiation's energy density drops faster as the universe expands and photons redshift.

Approximately how long after the Big Bang did matter's density surpass that of radiation, initiating the matter-dominated era?
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