This paper was submitted nearly two weeks ago.

One would expect Dr Penrose to have issued a statement by now if he wasn't involved.

Instead, ten seconds on google reveals him discussing the research in question with a reporter from the BBC ...

http://www.bbc.co.uk/news/science-environment-11837869

I am becoming concerned about these comments on articles that seek to discredit them without putting in effort commensurate with the article itself. I saw another earlier today where someone claimed that a statistical test used in an article was not correct, but provided little rationale other than the claim. Perhaps the commenter was right, but it strikes me that I must be more careful in believing off the cuff remarks, especially when comparing them with research papers that have been written only through much effort and care.

I suppose this is just another variant on cheap criticism that lacks the kind of expertise and context as the author of the thing criticized. You have to treat it with even more skepticism than the original.

"without putting in effort commensurate with the article itself"? You're suggesting that in order to be allowed to criticize something on a web forum, one would have to invest months of one's time beforehand?

Your own criticism seems to commit the logical fallacy of "argument by effort" (and assumes that there can't be any shoddily-thrown-together research papers or ones written by outright cranks).

How about we judge both articles and comments on the merit of their specific content?

Besides, reminding people that arxiv is not a peer-reviewed source and does not by itself lend credibility to a paper does not even represent criticism of the paper itself, just some additional context in which to judge it.

The fact is, the arXiv is seen as a legitimate and respectable place for scientists to post preprints.

V.G. Gurzadyan is well-known in the physics community and wouldn't risk his reputation by posting papers with phony coauthors.

Peer review and reputation are nice, but the acid test of any scientific model is whether it works. For example, is the model consistent with known observations, and does it make good predictions?

Right, but the problem is that us non-experts can't tell whether something posted on the arXiv holds water or not. Being posted on the arXiv carries very little signal.

Don't get me wrong: I love the arXiv and use it regularly. Long papers can be posted there, get disseminated quickly, and can be downloaded freely. The problem I have is that many people think anything on the arXiv is automatically true -- but there's lots of cranks posting proofs of P ?= NP and etc.

Yes, the acid test is obviously whether or not it works, but that's why we need to wait for the experts to figure it out and vet it.

The world in general is a legitimate and respectable place for physicists to publish preprints, but you still shouldn't believe everything you hear in the world. I think that's the point. It's not that arxiv sucks, but that it doesn't lend any credibility to the things published there, so we need to be skeptical. For those of us who are not the author's peers, taking non-peer reviewed work as anything more than speculation is likely to lead to false beliefs.