On 10/25/18 12:15 PM, Phillip Helbig (undress to reply) wrote:
In article ,=20
"Richard D. Saam" writes:

There have been recent cosmological experimental disclosures
represented in part by the following:

The 7Be(n,p)7Li reaction and the Cosmological Lithium Problem:=20
measurement of the cross section in a wide energy range at n\_TOF (CERN)
https://arxiv.org/abs/1806.03050
"The new estimate of the 7Be destruction rate based on the new results
yields a decrease of the predicted cosmological Lithium abundance of
~10%, insufficient to provide a viable solution to the Cosmological
Lithium Problem."
What is the resolution to the Lithium problem?

I, personally, don't know. Note, however, that the observations are not
easy.
something amiss with BBN?

No WIMPS have been found in reference to the dark matter problem.
What are the dark matter alternatives?

Primordial black holes are still viable.
but there are arguments against black holes as dark matter
https://arxiv.org/abs/1808.05910
Also, absence of evidence is
not evidence of absence. Even though we knew the sources and how many
were produced, it still took a long time before neutrinos were
discovered. Since practically nothing is known about WIMPs, there are
no robust predictions for cross sections and hence reaction rates.

Collective Effects in Nuclear Collisions: Experimental Overview
https://arxiv.org/abs/1810.06978
Viscosity plays an important role in measured LHC RHIC nuclear dynamics
Does this viscosity experimental result
influence BBN gas phased mechanisms?

Do you have reason to think so? BBN seems reasonably successful.

Yes, observed BBN expressions are reasonably successful
(except for the Lithium problem),
but the realm of fluid viscosity is different the gas kinematics.
It implies that we are looking at gas phase BBN
and there also exists a viscous BBN,
something like looking at the steam
but knowing the presence of water somewhere.

MILKY WAY CEPHEID STANDARDS FOR MEASURING COSMIC DISTANCES AND
APPLICATION TO Gaia DR2:
IMPLICATIONS FOR THE HUBBLE CONSTANT
https://arxiv.org/abs/1804.10655
The Planck H0 =3D 67.4 km/s/Mpc is based on CMB.
The reported H0 =3D 73.24 km/s/Mpc is based on photometric parallaxes.
What mechanism explains the difference?

Add the error bars and you have a three-sigma difference. Most would
consider it irresponsible to base a detection on three sigma, so why
base a tension on it.

The paper reports a 96.5% confidence level
for the difference in the HOs 67.4 and 73.24 km/s/Mpc:
'The best-fit distance scale is 1.006 =C2=B1 0.033 , relative to the scale
from Riess et al. (2016) with H0 = 73.24 km s--1 Mpc--1 used to predict
the parallaxes photometrically, and is inconsistent with the scale
needed to match the Planck 2016 CMB data combined with =CE=9BCDM at the 2.9\sigma
confidence level (99.6%). At 96.5% confidence we find that the formal
DR2 errors may be underestimated as indicated.'

The universe increased expanding rate
is an expression of dark energy measured by supernovae type II events.
What is dark energy?

Observationally, it is indistinguishable from a cosmological constant.
Theoretically, there is no reason it is not the cosmological constant.
There is no problem.

Here are some Weinberg's thoughts on the problem:
http://supernova.lbl.gov/~evlinder/weinberg.pdf

'The problem of the dark energy is also central to today's physics.
Our best attempts at a fundamental theory
suggest the presence of a cosmological constant
that is many (perhaps as many as 120) orders of magnitude greater
than the upper bound set by astronomical observations.Until it is
solved, the problem of the dark energy
will be a roadblock on our path
to a comprehensive fundamental physical theory.'

The cosmological constant problem or the vacuum catastrophe
indicates a vacuum energy theory differing from experiment
by 120 orders of magnitude.
What is the vacuum energy?

It is clear from quantum field theory what it is. Why the observed
cosmological constant is much smaller is not completely clear, but
years ago Weinberg came up with an anthropic explanation, which no-one
has refuted. Also, look for the paper by Bianchi and Rovelli. This is
probably another non-problem.

ditto Weinberg's thoughts from above

Is there a common theoretical mechanistic thread
connecting these experimental dots?

Probably not. To prove that there is, one would have to construct such
a theory.

Maybe the mechanism as simple as recognizing an entirely different phase
analogous to liquid and gas relationships.
Then observational cosmology and associated theories
are not eliminated but complemented.