B Dark Energy Fluids: Read the Latest Research

[wolram]

Although I am unable to judge this paper it should make an interesting read to toughs that can.
https://arxiv.org/abs/1810.00269

 

[.Scott]

It is an interesting article.

One of their claims:

Here we investigate the limits imposed by thermodynamics to a DE fluid. We proof that thermodynamics rule out DE fluids.

Their conclusion:

Therefore, we believe that we have demonstrated precisely that the vacuum energy remains the strongest candidate to explain the current accelerated expansion of the Universe and the cosmological constant problem remains as one of the biggest problems of the theoretical cosmology.

 

[kimbyd]

Haven't read it yet, but at first blush this would seem to also rule out inflation, which makes me immediately skeptical.

 

[kimbyd]

Okay, I've skimmed the paper, and I really doubt that this is saying anything of note. Their thought process is to apply classical (non-quantum) thermodynamics to perfect fluids, and derive the consequences for these fluids in an expanding universe. It's an interesting bit of math, but I really don't think it applies to the problem at hand.

Dark energy models are fundamentally quantum-mechanical, and I don't think that conclusions can be drawn about their thermodynamic properties without using that fact.

There's also the potential issue that we don't yet know how to do the thermodynamics of gravity except in certain special cases. It might be possible that this complication doesn't apply here (a homogeneous, isotropic universe with dark energy might be fine), but it's a major caveat that needs to be examined.