Session 62 - Workshop on the Future of Antarctic Astrophysics - II.
Topical, Oral session, Wednesday, June 10
Presidio,

## [62.11] Scientific Context for CMB Anisotropy Observations

E. L. Wright (UCLA Astronomy)

The anisotropy of the Cosmic Microwave Background provides a wealth of information about the initial state and subsequent evolution of the Universe. The primary anisotropies, present at the time of recombination only 300,000 years after the Big Bang, provide information about the primordial perturbation power spectrum for angular scales larger than the horizon at decoupling (\theta > 2^\circ), and further information about the modification of this power spectrum by the interactions with matter at angular scales from \theta = 1^\circ to 0.06^\circ (from the Doppler peaks to the thickness of the last scattering surface). Secondary anisotropies produced by non-linear matter density perturbations after recombination extend to even smaller angular scales and can have either a thermal spectrum (\Delta T) or a Sunyaev-Zeldovich spectrum (\Delta y). The Microwave Anisotropy Probe (MAP), to be launched in 2000, will measure \Delta T and its polarization for angular scales \theta \geq 0.21^\circ, but further ground-based, balloon-borne, and space-borne (PLANCK) observations will be needed to provide better polarization sensitivity, measurements of the \Delta y anisotropy, and sensitivity to smaller angular scales. Observations from the South Pole can provide the short wavelength data needed for the determination of \Delta y and the large telescopes needed for small angular scales, and will provide a powerful test of cosmological models.