Colloquium
Dark Energy and Cosmic Sound
Abstract
I will discuss how the acoustic oscillations that propagate in the photon-baryon fluid during the first million years of the Universe provide a robust method for measuring the cosmological distance scale. The distance that the sound can travel can be computed to high precision and creates a signature in the late-time clustering of matter that serves as a standard ruler. Galaxy clustering results from the Sloan Digital Sky Survey reveal this feature, giving a geometric distance to a redshift of 0.3 and an accurate measurement of Omega_matter. I will review our recent work on the theory and practice of the acoustic oscillation method and our latest cosmology results from SDSS-II. I will then present SDSS-III, which will use the acoustic method to produce 1% distance measurements in order to map the curvature and expansion history of the Universe and measure the evolution of dark energy.
About the talk
SLOAN Digital Sky Survey, CfA Harvard, USA
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About the speaker
Dr. Daniel Eisenstein studies cosmology and extragalactic astronomy with a mix of theoretical and observational methods. His dominant focus over the last decade has been on the development of the baryon acoustic oscillation method to measure the cosmic distance scale and tudy dark energy. Dr. Eisenstein received his Ph.D. from Harvard University and then held postdoctoral positions at the Institute for Advanced Study and the University of Chicago. He was on the University of Arizona astronomy faculty before moving to his current position as a professor of astronomy at Harvard University. He has beenactive in the Sloan Digital Sky Survey since 1998 and is currently the irector of SDSS-III. He is now serving as chair of the National Science oundation Astronomy Portfolio Reviewcommittee. He has been a member of numerous other scientific collaborations and national committees.
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