Research Interests

My research is on the testing of cosmological models of the Universe using new telescopes and instruments to image the intensity and polarization of the cosmic microwave background radiation, the fossil radiation from the early Universe. Through detailed measurements of the background radiation, my research group and I have shown that the curvature of the Universe is flat, supporting inflationary models and providing a determination of the total density of the Universe. We find that ordinary matter, the stuff of stars and us, accounts for only about 5 percent of the density. Another roughly 30 percent is composed of dark matter, presumably a yet-to-be-identified particle. Even less is known about the remaining, dominant component: the mysterious dark energy that apparently is causing the expansion of the Universe to accelerate. I plan to learn more about the nature of dark energy by measuring its affect on the density evolution of the largest bound objects in the Universe: clusters of galaxies. I will inventory the clusters in the distant Universe by surveying large regions of the sky for the small distortions in the background radiation caused by its interaction with hot cluster atmospheres, the Sunyaev-Zel?dovich effect.

Membership Type

Member

Election Year

2002

Primary Section

Section 12: Astronomy

Secondary Section

Section 13: Physics