Debate: the Values of Cosmic Parameters
H0 | q0 | Ωm |
Ωb | fb | σ8 | n
Topics to Investigate: Observational Constraints
The goal is to learn about observational constraints on cosmological
- H0 from direct measurements (e.g., HSTKP)
- q0 from type Ia supernovae (e.g., Hi-z;
- Age constraints [f(q0,1/H0)] from globular clusters
- Ωb from deuterium & other light element abundances
- Ωm from
- large scale structure (e.g., 2dF;
2dF-lite, and many, many SDSS works)
- cluster baryon fractions (e.g., Evrard)
- cluster mass-to-light ratios (e.g., BCDO; CNOC)
SHF combine several of these
- ΩΛ from gravitational lensing statistics (e.g.,
- Ωm + ΩΛ from the cosmic microwave
background (e.g., WMAP)
- See the more general list of
for more ideas.
Also see the extended reference list for further pointers.
A brief discussion combining many of these topics is given by
The Observational Case for a Low Density Universe with a Non-Zero Cosmological Constant
Ostriker & Steinhardt 1995, Nature, 377, 600
I will lead a discussion of this paper to launch our more detailed
discussion of the individual observational constraints.
Note that many of the observational constraints often boil down to a statement
like "Ωbh2 = 0.019 +/- 0.001." This is the
essence of what you're after, though of course you need to understand the
method in order to appreciate how the result is obtained and what might go
wrong. But we will need something like this as a bottom-line answer for
intercomparison of results in the culminating debate.
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