CMB Science Goals

 

 Origin of Large Scale Structure The CMB provides information on the initial conditions for large scale structure such as galaxies, clusters of galaxies, etc.

Origin of the Universe and Ultra-High Energy Physics CMB observations reveal information on the origin of space-time and the energetic processes occurring at that epoch and succeeding epochs.

Geometry & Dynamics of the Universe CMB observations provide information on the geometry and dynamics of the Universe. These include: the metric, open/flat/closed, shear, vorticity, and anisotropic expansion. The current limits on the rotation of the Universe are quite tight.

Determination of Cosmological Parameters Accurate, high-resolution CMB observations provide can provide precise determination of various cosmological parameters, e.g. the total mass-energy density of the Universe (Omega_total), the Hubble expansion rate (Ho), the density of baryons (Omega_b) in the Universe, various parameters of inflation or of topological defects, and the cosmological constant. These must be determined within the context of a specific model. Detailed CMB observations are capable of discriminating between cosmological models.

Discriminate between various cosmological models and provide a precision test of them in addition to determining their cosmological parameters. As shown in the figure below, the anisotropy power spectrum -- rms fluctuation power at each angular frequency ( proportional to 1/angle) -- is a strong means to discriminate between cosmological models.

 

Figure caption notes:
sCDM is standard Cold Dark Matter model with critical density.
oCDM is an open universe with Cold Dark Matter model
Lambda CDM is a model universe with Cold Dark Matter and enough cosmological constant to make space flat
STRINGS is a model where large scale structure is seeded by GUT strings.