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Old September 1st 18, 10:33 AM posted to sci.astro.research
Steve Willner
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Posts: 1,172
Default Missing matter found in the cosmic web

In article ,
Bruce Scott writes:
Do we have solid evidence that it is _different from zero_


If by "it" you mean dark energy, yes. There are three independent
lines of evidence: the CMB fluctuations, the SN distances, and baryon
acoustic oscillations. All three agree on the values within their
respective uncertainties.

and if so what does the curvature of the universe have to be?


The universe is flat to within 0.5% or so.

You can find a good summary in the _Planck_ 2015 paper at
https://www.aanda.org/articles/aa/ab...a25830-15.html

The paper is open access, and there are links to both html and pdf
versions. Look in the various tables, but you will have to read the
text for the symbol definitions. In particular, watch out for h =
H_0/100 =~ 0.67, which is not very close to 1.

I guess [dark energy] is the same thing as "cosmological constant".


The term "dark energy" means something like a cosmological constant
but allows for a more general case where the (negative) pressure
varies with time. So far there is no evidence it does.

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