Discover the Latest Baryonic Mass Figures from the Galaxy Red Shift Survey

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The latest analysis from the 2dF Galaxy Redshift Survey indicates a baryonic matter density of approximately 23%, significantly lower than the previously accepted figure of 30%. This study utilized a sample of over 221,000 galaxies and employed a direct Fourier method for power spectrum analysis, revealing evidence for baryon oscillations consistent with Cold Dark Matter (CDM) models. The findings suggest a need for reevaluation of the matter content of the universe, particularly in light of cosmic microwave background (CMB) data. Discussions among participants highlight concerns about the implications of these new figures for the Big Bang model and the potential for unknown factors in quantum physics. The evolving understanding of cosmic composition continues to challenge established theories in cosmology.
wolram
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The latest figures for baryonic mass etc.
 
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wolram said:
The latest figures for baryonic mass etc.

Hi wolram, I think for some reason you did not get the URL into the post, at least at first.

I think the URL is
http://arxiv.org/abs/astro-ph/0501174

The 2dF Galaxy Redshift Survey: Power-spectrum analysis of the final dataset and cosmological implications
S. Cole et al., (The 2dFGRS Team)


"We present a power spectrum analysis of the final 2dF Galaxy Redshift Survey, employing a direct Fourier method. The sample used comprises 221,414 galaxies with measured redshifts. We investigate in detail the modelling of the sample selection. A new angular mask is derived, based on revisions to the photometric calibration. The redshift selection function is determined by dividing the survey according to rest-frame colour, and deducing a self-consistent treatment of k-corrections and evolution for each population. The covariance matrix for the power-spectrum estimates is determined using two different approaches to the construction of mock surveys which are used to demonstrate that the input cosmological model can be correctly recovered. We are confident that the 2dFGRS power spectrum can be used to infer the matter content of the universe. On large scales, our estimated power spectrum shows evidence for the `baryon oscillations' that are predicted in CDM models...
... This shift is largely due to the signal from the newly-sampled regions of space, rather than the refinements in the treatment of observational selection. This analysis therefore implies a density significantly below the standard $\Omega_{M} =0.3$: in combination with CMB data from WMAP, we infer $\Omega_{M} =0.231\pm 0.021$."

stranger and stranger
It used to be that Dark Energy was 70 percent and Matter (baryonic plus dark) was 30 percent

now, if I understand the abstract, they want us to believe that Matter is only 23 percent. Maybe i am missing something. i will take more of a look.
they could be wrong, I guess. Maybe someone who follows this will comment.
 
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Sorry Marcus i did post the url, maybe some problem my end.
This one has me thinking, perish the thought, i think that something
is going on in the quantum world that we do not know about.
 
The bimodal distribution of the data is really striking.
 
marcus said:
now, if I understand the abstract, they want us to believe that Matter is only 23 percent. Maybe i am missing something. i will take more of a look.
they could be wrong, I guess. Maybe someone who follows this will comment.
The best guess numbers have hovered around 25 - 75 for the past few years:
http://arxiv.org/abs/astro-ph/0302207
This flat universe model is composed of 4.4% baryons, 22% dark matter and 73% dark energy
 
marcus said:
if I understand the abstract, they want us to believe that Matter is only 23 percent.
I could have told you that! [http://www.kluweronline.com/oasis.htm/5092775 predicts a cold matter density of 22.2% (2/9)]

Garth
 
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By CHRONOS
This flat universe model is composed of 4.4% baryons, 22% dark matter and 73% dark energy
--------------------------------------------------------
I think i read somewhere that if baryonic mass exceeded 4.4% by
a few percent, then the big bang model would be in trouble, if this
is so what is the max min baryonic matter allowable in the BB model
 
wolram said:
By CHRONOS
This flat universe model is composed of 4.4% baryons, 22% dark matter and 73% dark energy
--------------------------------------------------------
I think i read somewhere that if baryonic mass exceeded 4.4% by
a few percent, then the big bang model would be in trouble, if this
is so what is the max min baryonic matter allowable in the BB model
Start here:
Primordial Alchemy: From The Big Bang To The Present Universe
http://arxiv.org/abs/astro-ph/0208186
Steigman is one of the foremost authorities on BBN.
 

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