Talk:Dark matter

Preprints to add after peer review

Putting these here to remember to check in on later:

• Oncins (2022) "Constraints on PBH as dark matter from observations: a review", comes with a video
• Bernard Carr et al. (2023) "Observational Evidence for Primordial Black Holes: A Positivist Perspective"
• Su, Li, and Feng (2023) "An inflation model for massive primordial black holes to interpret the JWST observations"
• Depta et al. (2023) "Do pulsar timing arrays observe merging primordial black holes?"

All four are pretty juicy relative to the dark matter composition question, which is why I'm a bit reluctant to add until they pass review. Sandizer (talk) 02:21, 5 October 2023 (UTC)

Probably worth checking in on those peer review statuses, as https://iopscience.iop.org/article/10.3847/2041-8213/ad1bf0 states as an unqualified premise that AGN were around from z ≳ 15 (see the second line in the Discussion section.)

... Carr et al. 2024 made it in Physics Reports: https://www.sciencedirect.com/science/article/pii/S0370157323003976 -- it's a pretty ambitious review with 68 pages and 451 references.

From the Conclusions: "much of the evidence point towards dark matter in PBHs with around a solar mass ... naturally explained if PBHs form at the QCD epoch and this is our preferred scenario." Sandizer (talk) 20:59, 15 February 2024 (UTC)

How old is matter?

Motsaathebekhanyisile (talk) 07:45, 18 February 2024 (UTC)

@Motsaathebekhanyisile: 13.8 billion years. Before that everything was energy, and before that it was basically only geometry. But logic is and has been forever. Sandizer (talk) 05:24, 27 February 2024 (UTC)

21st century history

@Johnjbarton: what is the reason for this deletion? Is there a way to keep the sources? Do you think they can be summarized better? 141.239.252.245 (talk) 08:16, 19 April 2024 (UTC)

Thanks for opening this topic.

I reverted the edit as I said in the summary because the content is not "History" of Dark Matter. No historian has analyzed the history of Dark Matter and shown how primordial black holes became the alternative. On the contrary, the current consensus is cold dark matter: Lambda-CDM.

The sources and a summary are already in the article in the section "Alternative hypotheses". As it stands it appears to be WP:UNDUE: with in the section "Alternative hypotheses" primordial black hole is given an entire paragraph while other alternatives rate a couple of words. Johnjbarton (talk) 15:18, 19 April 2024 (UTC)

Short description

@Banedon the short description for this article currently reads as

Hypothetical form of matter that interacts with gravity, ...

getting cut off. Remember, the short description doesn't need to have as much detail as a lead sentence and is mostly used to disambiguate. Most people see the SD in the search bar, where they've typed in something that is similarly-titled, not similarly-themed.

I believe "Hypothetical form of matter" would scan quickly, as guidelines suggest, and disambiguate well enough from the other articles that have "dark matter" in the name, which are mostly works of fiction. The closest that might cause confusion is Dark matter halo, which has SD "Theoretical cosmic structure". But since you are engaged on this topic I will leave it to your judgement. Wizmut (talk) 04:16, 31 May 2024 (UTC)

I think it needs to say more than that, but a little m:ore brief, such as "Hypothetical form of matter that interacts with gravity, but not with the electromagnetic field" Bubba73 ^{You talkin' to me?} 05:01, 31 May 2024 (UTC)