19 February 2004

Speaker: David Spergel (Princeton University)

Title: WMAP and Beyond

Abstract: The Wilkinson Microwave Anisotropy Probe (WMAP) has made an accurate full-sky measurement of the microwave background temperature and polarization fluctuations. These measurements probe both the physics of the very early universe and the basic properties of the universe today. The WMAP measurements rigorously test our standard cosmological model and provide an accurate determination of basic comological parameters (the curvature of the universe, its matter density and composition). When combined with other astronomical measurements, the WMAP measurements contrain the properties of the dark energy and the mass of the neutrino. The observations also directly probe the physics of inflation: the current data imply that the primordial fluctuations were primarily adiabatic and nearly scale invariant. Many key cosmological questions remain unanswered: what happened during the first moments of the big bang? what is the dark energy? what were the properties of the first stars? I will discuss the role of on-going and future CMB observations in addressing these key cosmological questions.

References for students:

1. Kosowsky, A, astro-ph/0102402, The Cosmic Microwave Background Lectures given at the Italian Society of Gravitational Physics summer school in Como, Italy, May 2000
2. Spergel et al.,First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters, ApJ, astro-ph/0302209, ApJSuppl. 148 (2003) 175
3. Peiris et al., First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Inflation,astro-ph/0302225, Astrophys.J.Suppl. 148 (2003) 213