The 'Huge-LQG' quasar 'structure' does not violate homogeneity

[Sesh]

There was some excitement a few months ago about the discovery of the Huge-LQG quasar structure, claimed to be the "largest structure in the Universe", which was said to violate the cosmological principle and the assumption of homogeneity of the Universe. Some previous threads on this topic on this forum are here and here.

Turns out this claim is wrong. A recently published paper (journal version here, free access version here) shows that the quasars actually support homogeneity as expected. A blog post explaining the issues at a less technical level is

Quasars, homogeneity and Einstein

A one-line summary would be "structures do not invalidate homogeneity; and the Huge-LQG is not really a structure anyway".

 

[skydivephil]

Very interesting, thanks for the link

 

[Mordred]

thats good news thanks for posting that, lol I will have to adjust my thinking on when Homogenous is considered. I used to use the value 100 Mpc. I'll have to adjust to 130 Mpc.

 

[marcus]

It seems that cosmologists like to challenge their own assumption of uniformity. From time to time some observations are found that seem to indicate significant nonuniformity and we hear doubts about homogeneity and isotropy (the roughly even distribution of matter at large scale).
Examples: "dark flow", Large Quasar Group (LQG), "Sloan Great Wall", "cold spot" or "great void".

After a while the excitement about a particular challenge quiets down and whatever it is seems to be accepted as understandable as a fluke or statistical fluctuation within the context of overall large-scale average uniformity. I don't know much about this at a detailed level, only a vague impression of general consensus that the Cosmological Principle still seems acceptable.

I wonder if there's a recent review article about this. Not just Large Quasar Group or anyone specific challenge, but giving an overview.

 

[sardar]

I am always excited about new discoveries and their potential to challenge our current understanding of the universe. However, it is important to approach these claims with a critical and analytical mindset. In the case of the Huge-LQG quasar structure, the initial claim of it violating homogeneity was based on a misunderstanding of the data. The recent paper and accompanying blog post provide a thorough and well-supported explanation of how the quasars actually support the assumption of homogeneity in the universe. This serves as a reminder of the importance of careful analysis and interpretation of data in the scientific community. While the discovery of the Huge-LQG may not be as groundbreaking as initially thought, it is still a valuable addition to our understanding of the universe. It is through these continuous efforts and corrections that we can continue to improve and refine our understanding of the cosmos.