[Inyokern]

Since only ~50,000 Judeans returned from Babylon, that leaves another half million unaccounted for. Technically they are not Jews since only those who returned from Babylon were accorded that name, but they certainly were Judeans, and essentially the same people.

There is no evidence that the Jews who returned to Israel thought of the ones who stayed behind in Babylonia (and the ones in Egypt) as anything but EXACTLY the same people as themselves. Your attempt to make a distinction between Jews and Judeans is silly because the language of the time made no such distinction.

FYI, it is believed that the synagogue was invented in Babylonia during the captivity and so there was some sort of Jewish religious practice going on in Babylonia between the captivity and the time many Jews from Israel returned there after the failed revolt against the Romans.

[LostTribe]

I'll say it a third time. ...they certainly were Judeans, and essentially the same people.. If you insist in making more of that than was intended or implied, then I really don't much care.