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Cosmological Parameters from Fits to WMAP Data (2003)
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| Description |
Symbol |
Value |
+ Uncertainty |
- Uncertainty |
| Total density |
Ωo |
1.02 |
0.02 |
0.02 |
| Dark energy density |
ΩΛ |
0.73 |
0.04 |
0.04 |
| Equation of state |
w |
< - 0.78 |
95% CL* |
-- |
| Baryon density |
Ωb |
0.044 |
0.004 |
0.004 |
| Matter density |
Ωm |
0.27 |
0.04 |
0.04 |
| Light neutrino density |
Ων |
< 0.015 |
95% CL* |
-- |
| CMB temperature (K) |
Tcmb |
2.725 |
0.002 |
0.002 |
| CMB photon density (cm-3) |
nγ |
410.4 |
0.9 |
0.9 |
| Baryon to photon ratio |
η |
6.1 x 10-10 |
0.3 x 10-10 |
0.2 x 10-10 |
| Redshift at decoupling |
zdec |
1089 |
1 |
1 |
| Hubble constant (km/s/Mpc) |
H |
71 |
4 |
3 |
| Age of Universe (109 yr) |
to |
13.7 |
0.2 |
0.2 |
| Age at decoupling (yr) |
tdec |
379,000 |
8000 |
7000 |
| Age at reionization (106 yr) |
tr |
180 |
220 |
80 |
| Redshift of reionization |
zr |
20 |
10 |
9 |
| Sound horizon at decoupling (o) |
θA |
0.598 |
0.002 |
0.002 |
| Sound horizon at decoupling (Mpc) |
rs |
147 |
2 |
2 |
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