HOW many free parameters in the standard model?
Chalky
at Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
Cosmological Interpretation
E. Komatsu, et al., 2009, ApJS, 180, 330-376
Table 1
This is available for free via
http://lambda.gsfc.nasa.gov/product/map/current/map_bibliography.cfm
However, AFAICT, they actually used SIX free parameters in their
lambda cdm model.
Can anyone confirm if this is correct?
If so, this would seem to refute Von Neumann's assertion that, with 4
one could make an elephant, and with 5, make it wave its trunk.
AFAICT there is still significant tension between the WMAP (only)
Maximum Likelihood Parameters, and those for WMAP + BAO + SN
In fact, the WMAP (only) Maximum Likelihood Parameter for Omega_Lambda
is more than 1.5 standard deviations away from the posterior
distribution mean for WMAP + BAO + SN
Oh No
>As you may have noticed, I have been examining the latest WMAP data
>at Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations:
>Cosmological Interpretation
>E. Komatsu, et al., 2009, ApJS, 180, 330-376
>Table 1
>
>This is available for free via
>http://lambda.gsfc.nasa.gov/product/map/current/map_bibliography.cfm
>
>However, AFAICT, they actually used SIX free parameters in their
>lambda cdm model.
>
>Can anyone confirm if this is correct?
There should be four cosmological parameters, H0, Omega, Omega_Lambda,
Omega_R, but
Omega+ Omega_Lambda + Omega_R = 1,
so that is three. I guess for WMAP there is also Omega_baryon, for CDM
models, which brings us back up to four, and some people make
Omega_Lambda variable (for which there is no meaningful evidence), which
makes five. Not sure what the sixth is, off the top of my head.
Regards
--
Charles Francis
moderator sci.physics.foundations.
charles (dot) e (dot) h (dot) francis (at) googlemail.com (remove spaces and
braces)
Chalky
> There should be four cosmological parameters, H0, Omega, Omega_Lambda,
> Omega_R, but
>
> Omega+ Omega_Lambda + Omega_R = 1,
Agreed
> so that is three. I guess for WMAP there is also Omega_baryon, for CDM
> models, which brings us back up to four, and some people make
> Omega_Lambda variable (for which there is no meaningful evidence), which
> makes five. Not sure what the sixth is, off the top of my head.
IIRC there is also an "equation of state" parameter (which I have
never actually understood), but which, perhaps, could encompass
variable Lambda, (and lots more besides)
There is also something about neutrinos embedded in the presented data
conclusions, which, I guess, makes the 6
Oh No
>On Dec 13, 10:04�am, Oh No <N...@charlesfrancis.wanadoo.co.uk> wrote:
>
>> There should be four cosmological parameters, H0, Omega, Omega_Lambda,
>> Omega_R, but
>>
>> Omega+ Omega_Lambda + Omega_R = 1,
>
>Agreed
>
>> so that is three. I guess for WMAP there is also Omega_baryon, for CDM
>> models, which brings us back up to four, and some people make
>> Omega_Lambda variable (for which there is no meaningful evidence), which
>> makes five. Not sure what the sixth is, off the top of my head.
>
>IIRC there is also an "equation of state" parameter (which I have
>never actually understood), but which, perhaps, could encompass
>variable Lambda, (and lots more besides)
yes, iiuc that is correct
>
>There is also something about neutrinos embedded in the presented data
>conclusions, which, I guess, makes the 6
>