when we talk abt BBN, we only talk abt the nucleons. whr did th electrons come from? was it just beta decay or something else?
At what time frame do photon's appear in the current Big Bang Theory?
Actually nucleons did not form during big-bang nucleosynthesis. The big-bang nucleosynthesis fuses them into light elements, fixing relative abundances of the elements. The nucleons formed previously in a period or process called baryogenesis. For electrons, the corresponding process is called leptogenesis.