From: Greg Aldering (aldering@panisse.lbl.gov)
Date: Sun May 04 2003 - 10:32:44 PDT
>On Sun, May 04, 2003 at 10:06:20AM -0700, Greg Aldering wrote:
>>
>> >I ended up just adding this text to the $w$ section, and nowhere else:
>> >
>> > The 95\% confidence limits on $w$ when our data is combined with WMAP
>> > and 2dFGRS are \mbox$-1.68<w<-0.85$ for the low-extinction primary
>> > subset, or \mbox$-1.82<w<-0.75$ for the full extinction-corrected
>> > primary subset. If we add an additional prior that $w\geq-1$, we
>> > obtain a 99\% upper confidence upper on $w$ of $w<-0.77$ for the
>> > low-extinction primary subset, or $w<-0.60$ for the
>> > extinction-corrected full primary subset.
>> >
>> >Is that good enough, if we just leave the normal 1-sigma error bars in
>> >the abstract and conclusion?
>>
>> Did you really mean 99% CL?
>>
>> The Spergel et al limit using CMB, 2dFGRS power spectrum, and HST Key
>> Project Hubble-constant limits is w < -0.78 at 95% CL. You should add
>> a sentance to that effect and note that our constraints are as good and
>> are complimentary in the sense that he do not use the Hubble constant
>> If we then add 2dFGRS, we can quote that separately in this context,
>> but then us it in the abstract.
>
>Note that the one I'm quoting right now *does* use the 2dFGRS galaxy
>distortion whatsit.
Right - but the 2dFGRS distortion measurement is independent of the
2dFGRS power-spectrum measurement. For the redshift distortion you use
the power-spectrum in a very different way. You rely on the fact that
the power-spectrum is spherically symmetric, and you assume that galaxy
fluctuations (related to the power spectrum, of course) trace mass
fluctuation. You also need the bias parameter, which comes from
internal comparisons of the power spectrum (from from the bispectrum to
be more precise), to relate the galaxy fluctuations to mass
fluctuations.
This is in contrast to the 2dFGRS power spectrum measurements, which
a) are useless without assuming a Hubble constant
b) rely on model-dependent fits to the power spectrum shape, like
the CMB but with much more of the power spectrum in the non-linear
regime which is model-dependent. (It is the non-linear regime
that gives most of the redshift distortion signal, but there
you are comparing the line-of-sight redshift power spectrum
with the transverse spatial power spectrum, and that comparison,
isn't model dependent.)
Since the WMAP constraint on w also needs the Hubble constant, the
Spergel limits are wholely dependent on the Hubble constant. Ours are
not.
>I will change my 99% to 95%. (That really was 99%.) Then I will spit
>sub cand 2 at you.
Cheers,
Greg
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