Talk:Dark radiation

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 1 September 2020 and 18 December 2020. Further details are available on the course page. Student editor(s): Ellistrev.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 19:48, 17 January 2022 (UTC)

Random Quotes From Papers Removes

Just removed the three-sentence last paragraph. Of the three, the first is not only meaningless without context, but also mis-quoted from the paper abstract, so wrong even with context. The second is just meaningless without context (but a straight quote from the abstract). The third might be a paraphrase or interpolation of the abstract (or might be quoted direct from the body, which isn't freely available), but it's still difficult to see how it could, alone, have any direct relevance to the article. The papers themselves might be interesting and relavent sources for an article on an as yet unproven theoretical subject, and so could be added back if someone knows offhand the wiki magic for non-inlined refs. 86.9.109.71 (talk) 03:37, 13 December 2014 (UTC)

What exactly is dark radiation?

If the sources currently linked in the article are anything to go by, there's no consensus for what is dark radiation. The Ackerman et al paper posits that dark radiation is a new electromagnetic-style field that couples only with dark matter (see also dark photon). The Archidiacono et al paper makes the more general case for dark radiation being an extra relativistic component in the universe.

I think the Archidiacono et al definition is more intuitively accurate. Ackerman et al's postulate is like calling a new matter-style field that couples only with dark energy, "dark matter". One could argue that it's a suitable name, but it's not something that most cosmologists will immediately think about. If "dark matter" is a matter-like component that we cannot directly observe, then "dark radiation" should be a radiation-like component that we cannot directly observe, too (i.e. Archidiacono et al's definition). A new kind of neutrino, for example, would qualify as dark radiation even though it may still not interact with dark matter.

Putting "dark radiation" into Google yields results like this, this and this which all adopt the Archidiacono et al definition. I think the current first sentence in the article should be changed then. If nobody objects I'll change it in a few days' time. Banedon (talk) 22:39, 14 September 2017 (UTC)

On second thoughts, I'm removing the disputed tag since I don't see the difference between an extra relativistic component and Hot dark matter. If anyone has a clearer idea of what dark radiation is, please share. Banedon (talk) 22:16, 18 September 2017 (UTC)