Ancient galaxies: lack of mergers vs. subsequent spatial expansion

[hkyriazi]

TL;DR

Has anyone had success in disentangling the phenomenon of galaxy mergers from that of spatial expansion in explaining the fact that distant galaxies are closer together?

Galaxies far away---that evolved soon after the Big Bang---are reported to be closer together than the galaxies we observe near us. This could be due to two distinct reasons. One is that relatively nearby galaxies, over time, tend to merge, and the ones we see from far away haven't had time to coalesce yet. The other reason is that the assumed spatial expansion of Big Bang Theory hadn't yet had time to separate those galaxies. Have any cosmologists succeeded in distinguishing these two possibilities?

 

[Jaime Rudas]

The fact that galaxies in the past were closer together isn't something we would have determined observationally, but something that follows from the expansion of the universe.

 

[hkyriazi]

I think I read a recent (and not definitive) article about observations from the James Webb Space Telescope, dealing somewhat with the issue (maybe in Nature or Nature Astronomy). I'll see if I can track it down.

 

[Jaime Rudas]

I think I read a recent (and not definitive) article about observations from the James Webb Space Telescope, dealing somewhat with the issue (maybe in Nature or Nature Astronomy). I'll see if I can track it down.

If that is so, in effect, it could be just one more of the millions of fulfilled predictions of the Big Bang theory, as well as any other exotic thing that comes to mind.

 

[Vanadium 50]

"I think I read somewhere" is hard to follow up on. I would hope that the article defines what "closer" means in an infinite universe where galaxies clump on multiple scales so we're all talking about the same thing.

 

[PeterDonis]

Galaxies far away---that evolved soon after the Big Bang---are reported to be closer together than the galaxies we observe near us.

Reported where? As has already been commented, you need to give a specific reference. Otherwise we don't have a valid basis for discussion.