A central focus of my work has been the development of the baryon acoustic oscillation method for the study of the cosmological distance scale and the evolution of dark energy. My collaborators and I have studied the behavior of the acoustic peak in both linear perturbation theory and numerical simulations and the practical implementation of the method on real data. I have been involved in many of the largest survey projects in astronomy, most notably the Sloan Digital Sky Survey.
Currently I am the Director of the Sloan Digital Sky Survey III, which includes a major large-scale structure known as the Baryon Oscillation Spectroscopic Survey. SDSS-III/BOSS will soon produce the most stringent cosmological tests from any redshift survey. Check this space!
I continue to work on SDSS-II data as well. Our 2005 paper announcing the discovery of the acoustic peak in the correlation function of SDSS data led to the development of a web page with various explanations and illustrations of the baryon acoustic oscillation phenomenon. Our most recent papers in 2012 achieve a 2% measurement of the distance to redshift 0.35; we infer from this a Hubble constant of 70 +- 2 km/s/Mpc and Omega_m of 0.27 +- 0.015!
In recent years, the acoustic peak method has become one of the mainstays of the study of dark energy. I have been involved with several different survey concepts, including ADEPT/JDEM/WFIRST and the Gemini/Subaru Wide-Field Multi-Object Spectrograph (which has now evolved into the Prime Focus Spectrograph concept).
My group has been pushing to demonstrate the reliability of the acoustic peak method down to 0.1% in distance, the statistical limit of the most aggressive of these surveys. We have developed large suites of cosmological simulations to achieve this. We are now working on the development of a new generation of cosmological N-body simulation code.
The evolution of a point-like initial density perturbation from Eisenstein, Seo, and White (2007). The graph shows the motion of the four cosmic components in spherical comoving coordinates. The baryon-photon acoustic wave travels outward to reach a radius of 150 Mpc (500 million light-years) and then stalls, creating an excess in the clustering of galaxies that we can still detect today. More information about this animation.