Has DeSitter radiation been observed or experimentally verified?

Question

I found an interesting article by Paul Davies (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.30.737) which involves radiation emmited by DeSitter horizons. But is it a fact that this radiation exists? Has it been verified?

And also, in the abstract he says:

Does the mining process allow the recovery of unlimited energy from the cosmological gravitational field?

What does this exactly mean?

"What does this exactly mean?" Davies seems to discuss this in the introduction. Could you be more precise on what you did not understand? — Níckolas Alves, Aug 29 '22 at 02:34
Hello, sorry for commenting after almost a month, I didn't see your comment. Anyways, what I don't understand is that: Is Davies' description of how energy would be mined from the cosmological gravitational field mainstream physics or is it an alternative hypothesis without much verification? And also, if it is mainstream physics, does it mean that as the universe expands, vacuum energy increases turning the vacuum into a metastable vacuum that (as Davies mentioned in the intro), due to quantum instability of false vacuum, would decay? @NíckolasAlves — vengaq, Sep 24 '22 at 14:27
And also, in the intro, he says that an effective lambda would make energy to appear in the universe, and therefore, the universe could avoid a final state of maximum entropy (i.e heat death). How would this mechanism work? How could the universe avoid such final? @NíckolasAlves — vengaq, Sep 24 '22 at 14:30
@vengaq I suggest editing these remarks into the original question.This way, it will be more clear (and it will also bump the question to the front page, so more people can see). — Níckolas Alves, Oct 01 '22 at 19:35

score 1 · Answer 1 · answered Aug 29 '22 at 02:37

De Sitter radiation as discussed by Davies in this paper is an instance of the Unruh effect in curved spacetime, as I discussed, e.g., in this answer.

As far as I know, there is no direct experimental evidence of the detection of this sort of radiation. However, there is indirect evidence in analogous situations. Namely

For the Unruh effect in flat spacetime, the existence of the effect can be understood as a requirement for consistency with usual Quantum Field Theory in flat spacetime, as discussed in arXiv:gr-qc/0205078
For the Unruh effect in flat spacetime, the existence of the effect can be understood as a prediction of classical electrodynamics. This is discussed in arXiv:1701.03446 [gr-qc]
arXiv:1903.00043 [gr-qc] "present[s] the evidence for the first observation of acceleration-induced thermality in a non-analogue system." (quoted from its abstract). Also, see arXiv:2205.06591 [gr-qc]
For Hawking radiation, an effect analogue to the Unruh effect, there is direct observation in analogue systems, as discussed by DOI:10.1038/s41586-019-1241-0

In short, there is no direct evidence of de Sitter radiation. Nevertheless, there is indirect evidence in similar situations.

Has DeSitter radiation been observed or experimentally verified?

1 Answers1

Linked