What I would like to know is whether there is any indication from the DES whether there is, in fact, any Dark Energy activity at all.
Last I heard, DE was discovered to be, probably, a product of a pervasive miscalibration. I have not heard of any retraction or rebuttal. The recognition coincides with evaporation of galactic rotation curves as an indication of Dark Matter, also not, to my knowledge, rebutted. Cosmology is not unique in systematically ignoring evidence against the existence of its favorite phenomena -- Nessie and Bigfoot fans, either -- but its claims are the biggest.
Huh? There is zero argument about the existence of dark energy in the scientific community. It's existence is obvious because you can actively see galaxies accelerating, on average, away from each other in all kinds of datasets observing the sky.
The questions are all about what actually causes it / the mechanism behind it, and details about its workings.
> It's existence is obvious because you can actively see galaxies accelerating, on average, away from each other in all kinds of datasets observing the sky.
No. Acceleration is inferred by fitting observed values of other quantities to the Friedmann equations.
I gather the precise validity of the Friedman equations depends on the universe being "homogeneous and isotropic", on a large-enough scale, yet not so large a scale as to render the terms meaningless.
But we keep finding the universe not to be uniform, even on a 100M parsec scale. A much larger scale would be uncomfortably close to the perceived size of the universe itself, flirting with that meaninglessness. So, it seems hard to know how the results are affected by such non-uniformity, or how much correction is needed.
There is plenty of debate still about Dark Energy.
...and it's been getting stronger lately as we've been finding more evidence that the visible universe is not homogeneous as we thought - which is one of the pieces of evidence for dark energy. We seem to be in a local empty area, and thus dark energy may no longer be needed to explain post-big-bang inflation.
Last I heard, DE was discovered to be, probably, a product of a pervasive miscalibration. I have not heard of any retraction or rebuttal. The recognition coincides with evaporation of galactic rotation curves as an indication of Dark Matter, also not, to my knowledge, rebutted. Cosmology is not unique in systematically ignoring evidence against the existence of its favorite phenomena -- Nessie and Bigfoot fans, either -- but its claims are the biggest.